Durability of concrete as affected by low air temperature at time of placing
by Floyd D Swenson
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master Of Science in Civil Engineering
Montana State University
© Copyright by Floyd D Swenson (1952)
Abstract:
In this study, plain and air-entrained concrete specimens made with two Montana aggregates were
subjected to storage temperatures varying from 45° F. to 5° F. immediately after casting for a period of
24 hours. The concrete specimens were subsequently given 27 days curing at 70° and 100 per cent
humidity. At the total age of 28 days freezing and thawing cycles were started on the specimens. One
freezing and thawing cycle consisted of 24 hours in a freezer with an air temperature of approximately
5° F. and 24 hours in a water bath at a temperature of 70° F. At the end of about 50 such freezing and
thawing cycles, one-half of the specimens were tested to failure in compression, the other one-half
continued, the freezing and thawing cycles.
An attempt was made to estimate the detrimental effects of the initial storage temperatures and of the
freezing and thawing cycles and to correlate these results with conclusions drawn from similar tests by
other authors, Besults from this study show a decrease in compressive strength up to 30 per cent from
that of normally cured concrete of the same age due to the initial storage temperature. The percentage
of decrease was generally higher for the lower, values of storage temperature, Two appendixes are
attached giving a brief outline of the con- siderations involved in making freezing and thawing tests,
and of the mechanism of disintegration. DURABILITY" OF OOWGRBiTE AS, AFFECTED BY
DOW AIR TEMPERATURE ;AT TIME OF PLACING
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FLOYD D . : SWENSON
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• A THESIS
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p a r t i a l f u lf il lm e n t , of; t h e 1,req u irem en ts
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Exajnining Gotanitteer
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Bozeman #. M ontana■
F eb ru ary s .1952
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Page
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A cknowledgement
A b s tr a c t
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I n tr o d u c tio n
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Purpose
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In p o rta n ce
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P re v io u s Work
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L ab oratory Equipment
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C oncrete Mixer
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S p ecin en Molds
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Curing Room
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F r e e z e r C hest
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S to r a g e Tank
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A ir D eterm in ator
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M a te r ia ls
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Procedure
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M ixing and C a stin g
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I n i t i a l F r e e z e r Procedure
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Curing
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T e s tin g o f C on p ression Specim ens
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F r e e z in g and Thawing C y cles
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Mix D ata
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R e s u lt s
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I n te r p r e t a t io n o f R e s u lt s
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1033P8
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C o n clu sio n s
S u g g e s tio n s f o r F u rth er Studgr
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A ppendix A
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142
- C o n sid e r a tio n s I n v o lv e d i n t h e ,M king; o f f r e e z in g and
' Thawing T e s t s on C oncrete
Appendix, B ■
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■Mechanism o f •d is in t e g r a t i o n
l i t e r a t u r e ■C ite d -and C o n su lted
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ACKNOWLEDGEMENT
T h is o p p o rtm it-y i s ta k en b y th e au th or t o e g r e s s h i s g r a titu d e
t o th e fo llo w in g |B r o fe s s o r R o b ert Ge De H art5 f o r h i s a d v ic e and s u g g e s tio n s on
th e problem s en cou n tered ^
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D r0, E ldon R . B odge5 f o r h i s a d v ic e on th e com p letion o f th e
w r it t e n t h e s i s 5,
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Bruno D a n is e v s k is 5 f o r h i s a s s i s t a n c e in co n d u ctin g th e
r o u tin e la b o r a to r y in v e s t i g a t i o n s 1
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The Bureau o f R ecla m a tio n a t Canyon F er ry Pam5 H elen a 9 Io n ta n a 9
f o r su p p ly in g th e a g g r e g a te s n eeded f o r p a r t o f t h i s stu d y 3
The E n g in eer in g Experim ent S ta tio n 9 f o r th e f i n a n c i a l a s s is t a n c e
■ t h a t made t h i s stu d y p o s s ib le *
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ABSTRACT
. Ba t h i s stu d y ^ p la in and, a ir -e n t r a in e d c o n c r e te specim ens made
w ith two $$ontana a g g r e g a te s w ere s u b je c te d t o s to r a g e tem p eratu res vary­
in g from ItS0 Fe t o 5 ° F 0 im m ed iately a f t e r c a s t in g f o r a p e r io d o f 2it
hour s o The c o n c r e te specim ens w ere su b seq u en tly g iv e n 27 d ays c u r in g a t
.700 F i and 100 p e r c e n t hum idity= At. th e t o t a l a g e o f 28 d a y s9 f r e e z in g
and thaw ing, c y c l e s w ere s t a r t e d on t h e specim ens= One f r e e z in g and thaw­
in g c y c le c o n s is t e d o f 2It hou rs i n a f r e e z e r w ith an a i r tem perature o f
a p p ro x im a tely 5 ° F= and 2 it hou rs i n a w a ter b a th a t a tem perature o f 70°
Po A t. th e end o f a b o u t .$0 su ch fr e e z in g ' and th aw ing c y c l e s , one-**half o f
th e sp ecim en s w ere t e s t e d t o f a i l u r e i n co m p ressio n , th e o th e r o n e - h a lf
co n tin u ed th e f r e e z in g and thaw ing c y c le s=
An a ttem p t was made t o e s t im a t e th e d e tr im e n ta l e f f e c t s o f th e
i n i t i a l s to r a g e tem p era tu res and o f t h e fr e e z in g : and thaw ing c y c l e s and
t o c o r r e la t e t h e s e r e s u l t s w ith c o n c lu s io n s drawn from s im ila r t e s t s by
o th e r au th ors=
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J l o s u l t s from t h i s s t u d y . show a d e c r e a se i n com p ressive s t r e n g t h
up t o 30 p e r c e n t from t h a t o f n o rm a lly ,cu re d c o n c r e te Of th e same, a g e
due t o t h e . i n i t i a l s to r a g e tem perature= The p e rce n ta g e o f d e c r e a se was
g e n e r a lly h ig h e r f o r th e lo w er v a lu e s o f s to r a g e tem perature=
Two a p p en d ix es a r e a tta c h e d g iv in g a b r i e f o u t lin e o f th e c o n -s id e r a t io n s in v o lv e d i n making f r e e z in g and thaw ing t e s t s , and o f th e
mechanism o f d is in t e g r a t io n =
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Ther p u rp ose o f , t h i s t h e s i s -was to d eterm ine t h e , e f f e c t o f ,law'
tempei-a-bure >on th e s tr e n g th and d u r a b ilit y o f concrete=,
-The, c o n c r e te was
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e x p o s e d , t o ■te n p e r a tu r e s - v a r y in g from 1|5 ° F-« to. 5 ° F= im e .d ia .te ly a f t e r ■
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p roxim ate t h o s e w h ich m ight, occu r ,du ring ,c o n c r e tin g • o p e r a tio n s in .the. ,
f ie ld ,,
T h is study! en d eavors t o in d ic a t e t h e s tr e n g th and. d u r a b ilit y ,which
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c o n c r e te exp osed t o t h e s e tem peratures=
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C oncrete i s n o rm a lly p la c e d during, .warm .or m oderate w eath er t o
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p r e c lu d e th e p o s s i b i l i t y o f harm or damage t o th e c o n c r e te due t o th e
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,O fcpiaceiaent i s l i k e l y t o f a l l b elow -UO0 F= d u rin g th e Wi hour p e r io d
a f t e r p la c in g c o n c r e te Or b elow 3 0 ° F= d u rin g th e ,Su cceed in g 6 days*
it;id > o ep m m en d ed th a t'p r o te c tiv e " m e a s u r e s Oei taken
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To p ro v id e -Some a r b it r a r y stan d ard o f s tr e n g th s t o u se in c o ld
w eath er c o n c r e tin g o p e r a tio n s j t h e American C oncrete I n s t i t u t e h a s sug­
gested^ t h a t a minimum s tr e n g th o f ^OO pounds p er square in c h b e a t t a in e d
b e fo r e f r e e z in g t o p r e v e n t permanent damage=2
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■ 1Bdvzard E= Bauer 0, P la in . C o n c rete* (3d„ e d .; Mew Io r k s McGraw-Hill
Book Cbmpany9 I n c 09 1 9 h 9 \s 200-201=
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fin is i n th e n o rth ern clim a te's j, w h ere. th e tem p eratu res a r e more or
I e S s s e v e r e ,; th e p lacem en t o f c o n c r e te m ust be suspended d u rin g a la r g e
p o r tio n .of th e y e a r or* a s an a l t e r n a t i v e , t h e f r e s h l y p la c e d co n cre te'
m ust b e p r o t e c t e d from f r e e z in g * ' The v a r io u s p ro ced u res f o r th e:',b o ld -.'
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w eath er p r o t e c t io n o f c o n c r e te a r e s’ (I); h e a tin g o f th e m ixing w ater* ( 2 )
h e a tin g ,of th e w a ter !and th e a g g r e g a te s* ( 3 ) p ro tb o tiv O :.co v erin g Of' ■
fr ,e s h COncrete j (U ): .h e a te d :e n c lo su r e f o f .th e ,s t r u c t u r e , and' ( 5 ) th e use,
o f ad m ixtu res t o low er th e f r e e z in g p o in t o f th e w a t e r , ' Any o r .s e v e r a l .
o f th e s e p r e c a u tio n a r y o p e r a t io n s 'may be u sed depending, on th e c lim a te
and tem p era tu re, c o n d itio n s a f f e c t i n g a s p e c i f i c p r o j e c t .^
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, removed and rep la ced - r e g a r d le s s , o f t h e : c o n d itio n s ,under w hich i t w as,,
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f r o z e n . W hile, th e s e s p e c i f i c a t i o n s , d o u b tle s s have m e r it , t h e r e '.is ia ;
p o s s i b i l i t y t h a t much c o n c r e t e .rem oved under t h e s e c o n d itio n s, m ig h t w e ll,
have' r e t a in e d enough, s tr e n g th or has, th e , a b i l i t y ., t o s u b se q u e n tly .,gain, ■
s u f f i c i e n t s tr e n g th t o .m e e t a l l . th e s tr e n g th and d u r a b ilit y req u irem en ts
,for. some c o n c r e tin g w ork.
Thus* i f a method o f a c c u r a te ly p r e d ic t in g
th e u ltin ia te s tr e n g th o f p rem atu rely f r o z e n c o n c r e te c o u ld b e ;devi,sed>
■ • &ohn H.; Bateman * M aterials of Construction^ (Toronto i ;Pitman
Publishing C o r p o r a t i o n s ; , 1 S » B . ;,. : ‘ ''''vV'1'
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, ex p ed ie n c e # d o b s e r v a tio n ,; i -As, compared - t o ,o th er 'con crete, s t u d i e s , r e , ■I d tiv e ijr ' l i t t l e I m fo r m d tim r is a v a il a b l e on, th is-'" su b jectv ',Whet, d a t a ’i s :
■-',a v a ila b le vfr'om d i f f e r e h t " so u rces1, is ' no^,' in' ,',good agreements-' th e r e ^ b e ih g ;'.1 ■
'' t^ o ,.distdnot-- - b e l i e f s $ , ( i ) , t h a t ',con crete ,/w h ich ,,h asb een fr o z e n . Btejr'an V1 .• ''V
ea-zf]^-i'iage/'duffe r s ' i i t t l e ,damage-^-dmd ( 2 ) th a t- f r e ^ ; e n c o n c r e te s u f f e r s ' a
,• l o s s ' i n - s t r e n g t h rin th e-ra n g e-,.o f t.O, to' .60,,,per 'cebti.'" A p r M c ip le :'rea so n v ;
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t e s t s !Sometimes-, have-; v e r y l i t t l e , c o r r e la t io n “to-'each : o th e r ^vimd as,',a' p o n * .' •
Sequenc'd#: the- t y p e s 1,o f t e s t s u sed /a re' no't s ta n d a r d iz e d ,;., T h is -i'a-aS.' I t - '. ■
, should,-bej,.: a t l e a s t u n t i l - s u f f i c i e n t ‘knowledge,.' h as been, b u ilt , up: t o pro*
. v id e a ,s ta n d a r d iz e d ..te s t, an assurbrioe. o f s u c c e s s ., ; I n donstrtictibn,*:.no
, attem pt., i s . made t o c o r itr o l c o n d itio n s ,,a s i n a" la b o r a tory.j, ,and: p p in id h s 1 ■
and r e s u l t s can be .e x p e c t e d ' to., d i f f e r .
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The f o llo w in g , q u o ta tio n ,b y,A , :Me,; f Unzbergy .w ritten f Or th e ; Engin-.
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p r e s e n te d 'h e r e in, i t s ,e n t i r e t y t o , provid e, a thorough knowledge o f .th e
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. G p n cretin g during, s e v e r e w in te r w e a th e r , i n t h e open a i r a w it h the;
p u rp ose o f f Qroing th e c o n c r e te t o f r e e z e b e fo r e s e t t i n g b e g in s ,, h as .
. been, c a r r ie d on i n R u s s ia Under s p e c i a l m ethods. d e v is e d by th e author#
' , /.w h o ,s ta t e s t h a t s in c e XSO^ he h a s u sed t h e s e m ethods i n th e U kraine
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f o r JiJany la r g e c o n c r e te and r e in fo r c e d b u ild in g s , w hich have a l l prov- 1
; ed s a t i s f a c t o r y o G oncrete p la c e d i n t h i s manner i s p r o te c te d t o keep ,
v.; . - i t i n a- fr o z e n c o n d itio n u n t i l sp rin g * «— E d ito r* ■
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A t th e moment b e fo r e a c t u a l s e t t i n g o f c o n c r e te th e cement g r a i n s .
,are en v elo p ed i n a t h in m o lecu la r f i l m o f w ater; and th e g r e a te r the,',,.
■;;..^proportions o f w a ter ,in' th e m is , t h e low er w i l l be th e s t r e n g t h o f
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C oncrete* ,I f c o ld w a ter i s u s e d , 'th e ,volume w i l l be le h s tbati-';,,;v'_
-w ith , h e a te d w a ter b u t th e s t r e n g t h w i l l be g r e a te r * Xf th e concrete;'';..
, V / f r e e z e s w h ile s e t t i n g , i t w i l l become a r i g i d n o n e la s t ic mass o o n s is t 'ing o f san d, cem ent and i c e p a r t i c l e s , and su ch a mass w i l l f a i l a f t e r
thawing* B ut by a llo w in g th e c o n c r e te t o f r e e z e b e fo r e s e t t i n g i t , , ■
. . w i l l b e in norm al c o n d itio n a f t e r th aw in g,, s o t h a t s e t t i n g Can th en •
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b e g in and p ro ceed t o com p letion *
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As th e c o n c r e tin g must be done' r a p id ly , th e forms must n o t be
< deep and th e r e in f o r c in g b a rs must be s o arran ged t h a t th e c o n c r e te
. w i l l f lo w f r e e l y and f i l l t h e form e q u ic k ly w ith o u t v o id s* Xt i s
a b s o lu t e ly n e c e s s a r y f o r th e c o n c r e te t o f r e e z e b e fo r e s e t t i n g b e g in s *
Xhe cement i s C o ld , th e a g g r e g a te must be c o ld and dry and t h e w a ter
m ust have a tem perature o f IjQ t o 5>0 d eg , if . The l e s s w ater th e r e i d ,
■ : th e b e t t e r th e co n crete* The' c o n c r e te i s . m ixed i n a - s h e lt e r e d lo c a ­
t i o n and i s p la c e d q u ic k ly i n t h in l a y e r s , ea ch la y e r b ein g thorough­
l y b u t r a p id ly tamped so t h a t th e r e w i l l be no s e p a r a tio n , or f r o s t
p la n e ,'b e tw e e n the, l a y e r s , th e fundam ental req u irem en t b e in g 1co n tin u ­
ous p la c in g and com plete f r e e z in g o f th e e n t i r e mass*
As soon a s th e p la c in g ' is , com pleted th e form i s covered w ith
b o a r d s * ,, C on crete s la b s a r e covered w ith ' sand or str a w , over w hich
. w ater i s poured and a llo w e d ’t o f r e e z e , t o p r e v e n t a ry thaw ing and
con seq u en t s e t t i n g a c t io n i n th e co n c r e te * When i t i s n e c e s s a r y t o
. s to p work b e fo r e c o m p le tio n , b e f o r e s t a r t i n g a g a in ,, warm w a ter i s to
b e poured o v er th e fr o z e n s u r f a c e , w hich i s th en scrap ed and roughen­
ed b e fo r e th e new c o n c r e te i s placed*.
The m ost d i f f i c u l t and most; im p ortan t o p era tio n i s th e w e ttin g o f
c o n c r e te in th e s p r in g w h ile th aw in g, a s th e v ery d ry n o rth ern w inds
i n th e BkrSine d u rin g w in te r can. ev a p o ra te m o istu re even from th e
f r o z e n co n cre te* Thus i t w i l l '1be s o d ry t h a t i t can n ot s e t and , i t i s ,
n e c e s s a r y to ; a p p ly w a te r , b u t th e w a te r -m ust be a p p lie d v e r y ca re­
f u l l y i n o rd er n o t t o wash o u t . th e cem ent*.
. , W inter -c o n c r e tin g by ,,methods t h a t employ .th e. h e a tin g , o f ,m a t e r ia ls :
.arid.1- k eep in g -trie '.concrete-: warm ,go .,that ;4t. w i l l s e t , p ro p erly , ,have ,.trie,,.";'''
. ,',diSridy^ritage o f g iv in g t o o .h ig h a -tem perSW -e f o r p r b p e r v s e t t i r i g j . 1_, ^I :w it lr trie r e s u lt ' t h a t th e. f r e e z in g method l i e s up trie f orm;work>f or 'a •’
V ^ ''co n sid era b le t im e , t h i s o b j e c t io n i s . s l i g h t in co m p a riso n .w ith t h e .• ■/
Ipfv. ^ d yaritriges-O fv g ettin g -the-.-concrete'‘. p la ced d u rin g th e s e v e r e w i n t e r y
^'(^,iShie.'-free.z'ing -m eth od .is .not.-em ployed'near-trie ,e n d ,o f th e coid ysp agori/.. •
, when a lt e r n a t e s p e l l s o f c o ld and warm w eath er may be e x p e c te d ,a 'v .
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order- t o o b ta in - c o n c r e te o f -good ■s t r e n g t h , t h e s e p o in t s m ust be c o s p lie d
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i t ( t h e p r e v io u s a r t i c l e ) i s v e r y in tr ig u in g -a n d I have made
, s e v e r a l attem pts- t o ob tain - lik e v - r e s u lt s i n th e la b o r a to r y b u t have .
-- Ia ile d o - I- h a v e 'n e v e r been a b le t o f r e e z e c o n c r e te i d a way th a t
" d id riot g e t m t e r n a l s e g r e g a tio n o f t h e 'm ixing w ater i n t o i c e c r y s ­
t a l s =. As lo n g a s th a t- c o n d itio n .e x is t s ^ I -do n o t s e e ^how we can .'
-e x p e c t t o have con crete' a s d u rab le a s - i t would o th e r w is e have b een ,
u n le ss- something- i s done t o r e c o n s o lid a t e trie c o n c r e te and e lim in a te ■
p o r e s ',le f t by t h e s e i c e C r y s ta la 0. ’.fu rth er ,,, i n our t e s t s we have
n ev er been a b le t o g e t a n y th in g l i k e 95 p er c e n t Of trie - o r ig in a l
S tren gth : ou t. o f a t e s t 'c y lin d e r t h a t w as f i r s t q u ick f r o z e n ,,t h e n
thawed. ■o u t and ,cured norm ally*^
V f l r f T - 1I v . . ; n i ’- ' v. 'l i' :,.iii-i|-.fl.iii.-
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' ' ' &&/$<> Gunzbergj, "Frozen C oncrete Used' in R u ssia n B u ild in g s ,"
E n g in eer in g ,'H e w s GViI '(K ugust 6 , 1 9 3 1 ), 2 0 ? .
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c r e t e I n s t i t u t e J o u r n a l, XlV (Noven&er 19h 2) $i 127-129»
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t e s t s , were con d u cted . I t i s d i f f i c u l t t o c o r r e la t e h i s r e s u l t s r a th
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t e s t s con d u cted a t t h e S in n c s o ta Highway, Departm ent * T h eir r e s u l t s 'show.
t h a t f r e e z in g c o n c r e t e .im m ed iately a fter),C a ,'S t# g . i s th e w o r s t c o n d itio n ',
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h ib it e d o n ly 3 1 p e r c e n t Cf, th e u n frozen sam ples * '■However5. th e y d id f i n d
t h a t c o n c r e te is, n o t g r e a t l y harmed by f r o s t a f t e r 2k t o '7 2' hours, cu rin g
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i f su b se q u e n tly g iv e n good c u r in g * , and t h a t two weeks f r e e z in g h as1 l i t t l e
i f an y more e f f e c t th an s ix t e e n hours f r e e z in g e x c e p t t h a t c o n c r e te g a in s
l i t t l e S tr e n g th w h ile fro ze n * ^
': f u r t h e r -e x p erim en ta l r e s u l t s r e p o r te d by H* H* S c o f ie ld ' may be
summarized, "as 'fo llo w s #
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a v era g e o f about j?0 p e r c e n t o f th e s tr e n g th o f th e norm al u n fro zen c o n C rete a t th e same age* ,
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con ten d s th a t , no harm. I s done by f r e e z in g provided, th e ,c o n c r e te ■i s .f r o z e n
b e fo r e a c t u a l s e t t i n g b e g in s < E» A» - Hagy su p p o r ts iU M* -Gunsberg i n t h i s /
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. we .had a c o n d itio n o f -about th r e e w eeks o f CloSe t o z e r o weather.^
and we poured f o o t in g s o f th r e e t o f i v e y a r d s . • We d id n o t make any
a ttem p t w hatever t o p r o t e c t t h e 1c o n c r e te ^ we, j u s t poured i t and " le t ...
i t freeze*', and a f t e r th r e e Weqks i t thawed' o u t an d , t h e . co n cre te
seemed j u s t a s p l a s t i c a s when'we poured ■i t . , Then w e .commenced t o
tak e, c a r e o f i t > a f t e r i t thawed o n c e . We' had made c y lin d e r s a,t th e
' tim e' i t w as.p ou red and p r o te c te d them a l l * We .made c y lin d e r s front% . JHd S c o f i e l d 5 "Hot/ F r e e z in g and-Thawing A f f e c t Concrete*"
C o n crete, XLV ( J u l y , .1937)* 12-13«
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t h i s fro zen , c o n c r e te a f t e r i t became , p l a s t i c a n d , cu red them , and
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. a f t e r , a s i x months p eriod ^ ,there"w as n e t over a f i v e p e r c e n t d if ~ ■
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on t h e - ground, f r o z e n a f t e r i t was f r e s h l y p o u red ;a t a tem p eratu re o f "1
eig h t-.a b o v e zerot... A fte r . I b y e a r s of. u se * th e C oncrete was. i n good' -,
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th e .la c k o f ,knowledge o f / t h e e x t e n t o f t h e f r e e z in g damage t o th e .con­
c r e t e 0 I t i s : p o s s i b l e t h a t , t h e ■c o n c r e te i n th e f i e l d . s t r u c t u r e s d l s * .1
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p o r o s it y .and lo w str e n g th * t h e p r e se n c e o f w a te r .w ith in Or-In;. c o n ta c t
w it h t h e c o n cre te* .and c o o l in g .t o a tem perature s e v e r a l ;d e g r e e s b elow
th e f r e e z in g p o in t o v e r an -a p p recia b ly lo n g p erio d *
T h u s.a c o n c r e te
c o u ld c o n c e iv a b ly :be d e sig n e d w hich w ould r e s i s t f r e e z in g t o th e e x te n t
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t h a t . l t would remain- s e r v ic e a b le ., w h ile o th e r d e s ig n s would f a i l a f t e r
exp osu re t o f r e e z in g o , •
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...A . Hagy» ”19U2 ACl Convention, Quiz S e s s io n „ "American Con­
c r e t e I n s t i t u t e J o u rn a l* XlV (November 191*2) •> ( 1 2 7 - 1 2 9 ■ ■■ • ' •
?Bo Co W a tts5:'V-l91t2 AC! C onvention Quiz -S essib n j UAmerican Con­
c r e t e I n s t i t u t e Jou rn al* H ? (November 1 9 1 2 ) 5 127- 1 2 9 .,
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io ;A® Eo C O llih S 5 H b estru ctio n o f C oncrete by F rO st55! American
1
C oncrete I n s t i t u t e J o u m a l5. XTI: (June. 1 9 1 5 ) 5 726-727»
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•MiOEATOBt EQUIPMENT:
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Mte&rig b t' t h e cojabrete' was ic e o r a p lis ie c l thryugh 'the u se d f 'a
ia ip r k t d iy ’
c u b ic 1I e e t vC k p a c itto' -T hfm T xer i t e r im anufaeW ek
by S e a t s fl Roebuck' and Gbnpany0 ' I t i s powered b y a Dunlap 1 /3 h op .0 s p l i t
p h ase motor operat ir ig 'a t 1739 repein=
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The drum o f th e’ m ixer r o t a t e s a t
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6 in® by 36 I n efl w ere m o d ifie d t o p r o tid e two molds f o r 6 lu „ c u b e se A ll,
m olds w ere o i l e d b e fo r e u s e 0
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f a c e was c o m p le te ly en ca sed i n a s h e e t m eta l I i h e r 0 The s h e e t m etal;
■ l i n e r was- g iv e n one 'boat Of an o i l s e a l e r and two eOats' o f.'w a terp ro o f ■
v a rn ish o ' The m o is t f IO det m a in ta in ed 109 p e r c e n t h u m idity; through th e '
u s e o f th r e e 'A i n 0, f o g h o z a le g mounted a t t h e c e i lih g o
C it y ta p w ater
was u sed a lm o st e x c l u s i v e l y t o su p p ly the, -fog n o z z le s a t a room tempera­
tu r e o f 7 0 ° R 0 - E ci was' u s u a lly m aintained' w ith o u t th e a d d itio n , o f h o t
w a ter o ReweVerfl d u rin g ex tre m e ly c o ld w eather* tem pered w a ter was need­
ed t o m a in ta in th e r e q u ir e d temper aturbo
A lthough som e' o f th e specim ens
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t u i h 'J n d u str ies Oompai^r t o bur s p e c i f i c a t i o n s . i n s i d e .dim en sions , pf' t h e
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sp u n :.glass in s u la t io n was u sed On a l l s u r fa c e s and w as c o m p le te ly e n - . , '
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A ra ck f o r h old in g, C oncrete sp ecim en s'w as made t o ; ■
p r o v id e fo u r sh elV es' a n d -th e f l o o r o f th e c a b in e t f o r s t o r a g e .,; Each o f - >
. the', s h e lv e s c o n ta in s ,c o o lin g , c o i l s ^ t h e s e n o i l s p r o v id in g 1-th e c o o lin g C l v •'
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Temperature-"in th e c h e s t was c o n t r o ll e d by a p r e s s u r e c o n t r o lle r
ty p e mercury s w it c h .
The com pressor u n it Was m anufactured bgr York and
a 1 / 3 h .p , C entury C a p a cito r S in g le Phase- Motor a t 1 7 5 ° rop .m . was u sed
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tu r e (a p p ro x im a tely 7 0° Jp0') was k ep t i n t h e tank t o c o m p le t e ly • cover a l l
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:--i . ! ;,- - The p e rce n ta g e o f a i r i n th e a ir * e n tr a in e d sp ecim en s .was d e t e r - ,
,
- mined by Acme A ir H e l d D eterm inator,., D ir e c t io n s s u p p lie d b y .t h e maim* f A ctu rer w ere f o llo w e d i n th e o p e r a tio n o f t h e de term in a to r... -
-
,
- I 6i- ' .'V. %
■' 1
■ K - ; ,
" -MTERIAiS'
. ‘i , *' > • .
A ggregate^w as s'dbured from tw o Montana S ooreeoi l o c a l a g g reg a te
.
from .th e' p i t o f th e G a lla t in Sand, and GraVaL Qompany a t B elgradO i . Montana '
Yv,. ,
(doi^'-i-lettey 'G*)j 'aaad: aggregate from' t h e 'B tr1Oau o f Reclam ation p la n t ^ t'V '
■,
-I
I ZrtUVv/,'.
1LA
G ^oh/E arry/.B am 'i i^ e le n a iVMontaiia ‘(ood e.
■ I*
1,'V ;
■'V'/i l i f ^eoaraa aggregate^ from B o lg rM a -Was graded BA ' M > *M h u s^ ','-i - -,.'K '4
•V ■■ 1 ; ,
.
aggregate, w as p r o d u c e d "fcgr C rushihgi whi,ch gave a sm all' percentage'' "■:'/
.
' o f f l a k y p a r t i c l e s 1and a r e la t iv e l y " la rg e; p e r c e n ta g e o f fin ed ®
1V ' '
■•■.•<•
^h eM ggP egd te o b ta in e d -fr'dia- Ganybn'.ferry Dam' w a s' produced 'byV'' '
r iv e r /d r e d g in g 'a n d ' c o n se q u e n tly th e a g g r e g a te co n ta in ed w e l l .-Pbundddr
p M t ie f e d V "The- a g g r e g a te r e c e iv e d # 0 W ell g ra d ed ’ i n th r e e g ra d ess
!"
3 / M in® t o ; 3 /8 M e 3,;;-3/8; I n / W 13 A 1I n ^ and 3 /d M * t o I l / B SnVr ;
E or m ech a n ica l g r a d a tio n O f-V g g reg a tes a s Usedi s e e T ab le I » /
’
■ : ■■■ ■'T ^ p e-Il iCement' Was used, i n a l l ,mixes'^ ' 'Mo e p e c i f i d in fo rm a tio n
i d a v a il a b l e on th e ch em ica l co m p o sitio n o f t h e Cementi b u t m ' sample:
t e s t e d ' a t T ridents. M n ta n a y showed a l k a l i p r e s e n t in q u a n t it ie s g r e a te r
th an
p e r Cent®
' ' '■' P rO tex was Used a s a n ’ adm ixture in th e -airmen t r a in e d concrete;®:
I t W a s added- at th e r a t e C f one -,ounce t o a s a c k 'o f cement'd A r
, v
'
''-'.'V
.
-17'
TABLE I
SIEVE ANALYSIS
B e lg r a d e A g g r e g a te
Coarse A ggregate
Sand
S ie v e
i
If
# 16
F lE T
# ib o
Pan
R etain ed P ercen t Gum. P ercen t S ie v e R eta in ed P ercen t Cum. P ercen t
R eta in ed
R eta in ed
R eta in ed
Chrams
Grams
R eta in ed
ISl1
2j l
651
2L2
" W
212$
1 .8
7 .7
1 0 .9
2k .?
LO.O
11. u
3 .5
1 0 0 .0
1 . 8*
9 .5 * "
2 0 . k*
8$ . l *
9 6 .3 *
1 0 0 .0
F.M. 2 .$ d
0
0
I"
111
"ITkfir
1/ 2"
1299
3/8"
2009
Ik o f2ld
Pan
*>36
0
0
2 .2
2 5 .8
3 9 .9
2 ? .9
k .2
1 0 0 .0
0*
0
2 . 2*
2 8 .0
6 7 .9 *
9 5 .8 *
loo.O
F.M. 6 .6 6
Canyon F e r r y A g g r e g a te
Coarse A ggregate
Sand
S ie v e
Z
#
#
#
ft
ti
16
30
Pan
*
R etained P ercen t Cum. P ercen t
R eta in ed P ercen t Cum. P ercen t
S ie v e
R eta in ed
Grams
R eta in ed
R eta in ed
R eta in ed
Grams
30
31U
29k
338
117U
290
108
1 .2
1 2 .3
1 1 .5
1 3 .3
4 6 .1
1 1 .4
2548
1 0 0 .0
4.2
1 . 2*
13.5*
I"
2 5 . 0*
3/4"
1/2"
38.3*
84.4*
95.8*
1O0.O
F.M. 2.58
IT B r
#4
Pan
490
1532
1282
1078
674
920
32
8 .2
2 5 .5
2 1 .3
OoOb
1 0 0 .0
8 . 2*
3 3 .7
55 .0 *
18.0
?3.0
1 1 .2
1 5 .3
8 4 .2 *
"TT"
These v a lu e s were used in computing th e f in e n e s s modulus
99.5*
loo.o
F.M . 7.4 7
HtOOBDBRE,
, Mixing;and Casting
‘,'iyj.'mjidittg and c a s t in g was perform ed i n accordan ce w it h AVSgSMU.
■''=
.'' ' . L
\
W ' '.' " , - ' '
D e s ig n a tio n G 1 9 2 -4 9 w it h th e f o llo w in g ex ce p tio n s?
r "'
(I)
''
'' '
.'4'
Ho a ttem p t was made t o com pensate f o r m ortar r e t a in e d in
th e la b o r a to r y m ixer o ' However fl a s much r e t a in e d m ortar a s p o s s i b l e was
- '
'
,
scrap ed tgr hand in t o th e rem ainder o f the- t e s t mixo
.
'
'
'
>■ ■
( 2 ) Specim ens f o r f r e e z in g and th aw in g t e s t s w ere e a s t i n ; 6 i n .
y,
by 6 i n . by 6 i n . c u b e s. T hese t e s t sp ecim en s were form ed by p la c in g :
'■ the' • c o n c r e te i n th e m olds i n o n ly two la y e r s o f a p p ro x im a tely equalvolum e> and .rodding ea ch la y e r 25 t i m e s . ' \
-
(3 )
A th r e e m inute m ixing tim e was u sed f o r p la in c o n c r e t e ,
w h ile a ir -e n t r a in e d c o n c r e te was mixed f i v e m in u te s.
'I n
-
1 ■
each b a tc h , th r e e 6 i n . by 12 i n . com pression C y lin d e r s and
tw o b ind' cu b es’ w ere e a s t .
One com pression c y lin d e r was t e s t e d a t 7 days
and two w ere t e s t e d a t 28 d a y s .
The two 6 i n . cubes w ere c a s t t o u se i n
' f r e e z in g and thaw ing t e s t s .
■
-
Throughput th e t e s t , th e m ix r a t i o was k ep t a s n e a r ly co n sta n t
as p o s s ib le .
Th# m ix r a t i o was l e f t a t I ; 2 § r 3 b y w e ig h t , P r o te x b ein g
added a t th e r a t e o f ap p ro x im a tely One ounce t o a sa ck o f cem ent in th e
a ir - e n t r a in e d c o n c r e t e .
per sa ck .
The w a ter ,.cem ent r a t i o was h e ld a t 6§ g a llo n s
Ho a llo w a n c e was made f o r w a ter a b so r p tio n b y a g g r e g a te , - s in c e
th e m i n o b j e c t iv e o f th e s e t e s t s was n o t t o c o r r e la t e th e w ater-cem en t
r a t i o t o th e e f f e c t o f low t e m p e r a tu r e s .. The w ater^cem ent r a t i o was
sim p ly h e ld a s c o n s ta n t 6 s p o s s ib le , so, t h a t th e s t o r a g e .tem p eratu res
would' be the', o n ly v a r ia b le i n th e t e s t s .
I n i t i a l F r e e z e r .P r o c e d u r e , ■....................................
, ;*
’
■ f
1
■
Jr
'
/"
-
1
■
='
f
Z 1'
11
■
1I1
'
r
1
'
'
",
‘
1
' I
",
•v."ii !'KvVvkV^Iia twb; 0 .$»*• cu b es ,frbmi ea b h 'batch ,were,’ plabed' # . t h e ' f r e e s # • , ■
-
.
-
.
. . .
-
.
'
•c h e s t im m e d ia te ly , a f t e r ca stin g , and m ain tain ed , a t , a c o n s ta n t ,,temperature.
''
L
^
1fold,.6 .p eriod ,-o f Zk h o u rs.
,
;
.'
T hese c o n s ta n t tem p eratu res - t o w h ich .ea ch s e t '
o f ,'two cu b es w ere ,s u b j e c t e d ranged from h$ ..to ■$ d eg ree s F° b y ab ou t 8
.
/
,
. '.
.
............... ,
d e g r e e s Fe i n t e r v a l s „, A f t e r . t h i s p e r io d , o f , 2k h o u rss th e ,specimens: Wbre' '
■■ 1'.
' .’r emoved,from. t h e .f r e e z e r ' and aH ow ed to . s e t f o r . 2h h ou rs,..in,,the 'labora*''''''
t o i y b e fo r e s t r ip p in g . , A f t e r s t r ip p in g , t h e specim ens..w ere .placed ' in'
. th e . m o ist c l o s e t t o cu re u n t i l a t o t a l , age 'of 28 days was a t t a in e d » .
Quring
................
...'
. '
’
.
.
.
.
.
, . The com pression sp ecim en s were, s t r ip p e d .a t . an a g e o f one day and
■
: p la c e d i i i . th e ; m o ist, c l o s e t U n t il a t o t a l a g e o f 7 , days and 28 d ays was ;
,
i
’ •
'V ’
a t t a in e d » ,The cu ring, o f th e s i x in c h cu b es h a s.b een m entioned p r e v io u s-. • ,
•
1Iyoi
' 1
'
'
,
..
,
.
,
.
.
1
Ii
■
,
:
■T e s t in g ; ; # ,,Compression, ,Specimens
" T e stin g , o f com p ression sp ecim en s,w a s perform ed i n accordan ce
w ith A*S4«M9 S ta n d a rd s,
ia lo
P l a s t e r o f p a r t s was u sed a s a cap p in g m ater- ,
A c tu a l t e s t i n g w as.perform ed i n a:Baldw in-Southw ark Tate. Emery,
U n ivers a l.,T e s t in g M achine o f SOQl5OQiQ pound c a p a c ity .
• in g u sed .w as 1000 pounds p er square in c h p e r m in u te.
The r a t e of. I o a d -
!
■
'
'
- 20-
• F r e e z in g -arid Thamzig 'C y c le s .
’.
- /T "
^
'V;
‘ jV* iflie'.vgi^c in c h -ctib es w ere:rem oved-Jfcoia, th e •m eisii c l o s e t a t a t o t a l." '.
•
' '
' '
,
They w ere p la c e d in a warmJ; d ry room, f o r Zh hours ' ■
"
,
.. ' '
'
a f t ^ f s h iO h 'th ey w ere w eigh ed t o th e n earest,;.IO- grams.' A f t e r 1w eighing^
' '•
■:
■
‘
%;.I'th l^ .'^ s r e .v iti^ r se d in-'d w a ter hath..fpr^ i,2%. hoursv.- iA ft e r ,this■!period'.'-of' \ •
', age.:;;Q£:'28' dayso
.
■' tim e thc^r,w e r e ■moved i n t o th e fr e e z e r , c h e s t a t 5 t o 10 d e g r e e s Fy' f o r
2h;:hohrso. T h e r e a fte r n one c y c le c o n s is t e d o f Z k hours i n th e water-',hath ,:
■v1I
'
.
;
.
,
'
.
;
■
1V-'. V-,:;.; ..
i' ,and,.2%' h o u r.s,in th e ,fr e e z e r =., A t th e end o f ev ery f i v e c y c l e s , th e s p e c ,
’■
'v'1{ i i e n s were a llo w e d t o a i r dry f o r 2t ,h o u r s and were rew eig h ed a f t e r ,
.
'‘
- '
-'- *
\
w hich t h e f r e e z in g and thaw ing c y c l e s w ere, r e su m e d ,, The tim e-tem per-:
■
, '
'
'
'
,
;
]1
•'
; ,
V| a tu r e -,curve s .£ o r th e f r e e z in g and thaw ing O yoies a r e shown in F ig u re I V -.
T hese c a r v e s w ere o b ta in ed by th e u se o f an ir o n - c o n s t a n t^ i therm ocouple
c a s t i n th e c e n te r o f , a t e s t s i x in c h c u b e ,
-2 1 80
^ / S p e c im e n T ea p era tu re
A ir T em perature
Tim e-H ours
-Water Tem perature
Specim en Tem perature
F ig u r e I 0
F r e e z in g cu rv e (u p p e r ) and th aw in g cu rve (Io w e r ) f o r s i x
in c h cu b es u n d erg o in g f r e e z i n g and th aw ing c y c l e s 0
-2 2 4
MJX DAm
’'-v
i *
!
-
i 1:
- * .- ■ ■
I
A t ■t h i s tim e an e x p la n a tio n o f t h e code l e t t e r s i s n eed ed .
....................................
,
.
,
, f i r s t . . l e t t e r o f th e cod e d e n o te s t h e mix. d e s ig n .
T he.
•
S in c e t h e m ix was h e ld
' c o n s ta n t th rou gh ou t th e t e a t , t h i s number i s t h e same f o r a i l sp ecim en s.
V
i
‘
! ,1
‘ .
' ' ' •(
" 7',.. '
«*
■.
1 -I .
; »
‘ The secon d l e t t e r d e n o te s th e so u rce o f th e a g g reg a te (G f o r B elg ra d e,
arid.F . f o r CianyOn F e r r y ) .
The t h ir d l e t t e r d e n o te s th e b a tc h number. ■
- The l e t t e r llXirt i s u sed -whenever an a ir - e n t r a in in g a g en t i s u s e d . . T hus,
%f b r exam p le, th e code 1G5X shows number Ohe- m ix , B elg ra d e a g g reg a te* ' b a tch number f i f e , and t h a t P r o te x was u s e d , .
,
,
As m entioned p r e v io u s ly * one 7 -d ay and two 2 8 -d a y com pression
specim ens were c a s t .
R e s u lt s o f th e s e t e s t s a r e g iv e n i n T ab le J J .
. Gonplete information on mixes i s summarised in ,Tables I I I and .
1?«
Mo change in proportions of m aterials was.made in the mixes
when,an air-entraining agent was added,
iV w as deemed advisable to'
keep th e same :watdr-cem ent r a t i o t o b e t t e r e v a lu a te Ahe e f f e c t , o f the'
>, ■ ' •
! 'i ■ .”" : ■ , >l'’
a ir - e n t r a in in g a g e n t . However $ th e q u a n t i t ie s were in c r e a s e d o n eq u a rter t o p r o v id e s u f f i c i e n t c o n c r e te s o th e p erce n ta g e o f a i r m ight
b e d eterm ined i d th e a i r d e te r m in a to r .
c
i’
'
■ '' -'.,'As seen
, - I, ' ■- :
i n th e ta b u la te d v a lu e s i n T a b le s^I I I and I F ) some.’,wide".
■■
,,
. . ■■;
,
... i ■
■
differences in slump were encountered fo r mixes th&t were' supposedly .
Cf th e same d e s ig n .
F or example* mixes'1G2X and IShX had slum ps o f
I 3 /k in,„ while mix iG3X had a slump o f 5 1 /k in .
,
Mot exact ,explanation
of; th is i s available* but the differences in, Amount of surface moisture
V
Vv-
’X
-2 3 TABLti I I
CQIlflitiSSIVti STRtiWiTHS
Water-Cement R a tio
B elgrad e No A ir-E n train m en t
7-Day
Average 28
V v K JL O
S tr e n g th Day S tren g th
p si
p si
fay W eight
B elgrad e A ir-E n tra in ed
A verage ZO
/-D ay
Code S tren g th Day S tren g th
p si
p si
IG l
1625
2880
108x
1247
1978
102
1660
2843
1G9X
1254
1958
103
1943
3149
IGlX
1840
3054
IGlt
1604
2618
1G2X
1804
2984
ig 5
1664
2980
1G3X
1777
2975
106
2118
3152
ig 4 x
2094
3115
107
2100
3125
A v er.
1669
2677
A ver.
1816
2964
Water-Cement R a tio 0 .5 7 7 by W eight
Canyon Ferrj r A ir-E n tra in ed
Cany Qn F erry No A ir-E n train m en t
7-Day
A verage 28
A verage 2d
7-Day
U vQ O
Code
S tr e n g th Day S tren g th
S tren g th Day S tren g th
p si
p si
p si
p si
IF l
2478
3840
IFlX
2169
3483
IF2
2376
3691
1F2X
2077
3029
1F3
1872
3288
1F3X
1767
3165
if 4
2259
3423
1F4X
2078
3211
1F5
2085
3280
IF SX
1989
2854
A ver.
2214
3504
A ver.
2016
3148
TABLE I I I
BELGRADE AGGREGATE
M X DATA
Code
Coarse
A ggregate
Sand
Cement
lb s .
lb s .
Ib a .
Water-CflSient R a tio 0 .5 7 7 b Y W eight
Temperature
Water P ro te x P er cen t A ir
C oncrete
Mix
CO.
lb s .
0 F.
Slump
In .
I n itia l
F r e ezer
Temperature
® F.
LGl
60
50
20
1 1 .5 5
—
——
7ii
3 /2
27
1G2
60
50
20
1 1 .5 5
—
—
72
2 IA
23
1G3
60
50
20
1 1 .5 5
—
—
72
I
36
lfiii
60
50
20
n .5 5
—
—
70
3
12
IfiS
60
50
20
1 1 .5 5
—
—
62
2 1 /li
1 9 .5
106
60
50
20
1 1 .5 5
—
—
65
2 3 /ii
iil
2fi7
60
50
20
n .5 5
—
—
67
2
U5
IfiQx
7S
6 2 .5
25
l i i .i i
10
10
71
6
U5
Ifi9X
75
6 2 .5
25
lii.ii
10
10
70
6
3 9 .5
IGlX
75
6 2 .5
25
lii.ii
5
ii.3
72
ii 1 /2
32
IfiZX
75
6 2 .5
25
lii.ii
5
h .9
72
I 3 /ii
25
IfiSX
75
6 2 .5
25
lii.ii
5
ii.2
72
5 VU
16
IfiiiX
75
6 2 .5
25
lii.ii
5
5 .2
72
I 3 /ii
7
TABLE IV
CANTON FERfiI AGGREGATE
MIX DATA
Water-Cement R a tio 0 .5 7 7 by W eight
3 /1 6 - 3 /h 3/8-3/U 3/U-l 1/2 Sand Cement Water
lbs.
Temp.
P ercen t C oncrete
P ro tex
Mix
Slump
A ir
CO.
in .
0 F
I n itia l
F re ezer
Temp.
6 F.
lbs.
lbs.
lbs.
lbs. lbs.
IF l
30
30
—
50
20
1 1 .5 5
—
—
71
I 3/U
3F2
30
30
—
50
20
1 1 .5 5
—
—
6U
I
IU
1F3
10
20
30
50
20
1 1 .5 5
—
—
70
3 1/U
21
IFU
10
20
30
50
20
1 1 .5 5
—
—
65
U 1 /2
U3
3F5
10
20
30
50
20
1 1 .5 5
—
—
68
3 3/U
32
IFlX
3 7 .5
3 7 .5
—
6 2 .5
25
1U.U
5
3 .8
68
U
1F2X
37.5
3 7 .5
—
6 2 .5
25
lU.U
5
U.2
6U
3 3/U
IU
1F3X
1 2 .5
25
3 7 .5
6 2 .5
25
lU.U
5
3 .1
70
5 1 /2
21
IFl4X
1 2 .5
25
3 7 .5
6 2 .5
25
1U.U
5
3 .2
65
6
U3
1F5X
1 2 .5
25
3 7 .5
6 2 .5
25
1U.U
5
3.U
68
8 1/2
32
5
5
S z-
A ggregate
Code
on th e a g g r e g a te could a cco u n t f o r t h e difference in Slunrp0 T h is p o s s ­
i b i l i t y i s m ade p la u s ib le by th e f a c t t h a t th e a g g r e g a te s a s u sed were
f i e l d ru n 3 and th e s u r fa c e m o istu re c o n te n t co u ld be e x p e c te d t o vary
from one m ix t o another=,
' ' .I t w i l l a l s o b e n o te d t h a t 10 c c 0 o f P ro te x was u sed in m ixes
'
,
'
■!■■■.
'
,
: :
108x and 10 % w h ile $ :,qe» o f P fo te x was u s e d in a l l su c c e e d in g a i r - ,
. <' '
;
i .wv.' ''
' ' __ '
''
''
'
' "
'
e n tr a in e d m ixes o’ !Phis change was (deemed) a d v is a b le i n o rd er t o reduce
: th e ..p e r c e n ta g e o f e n tr a in e d a i r t o th e u s u a l w orking lim it s * ,
, O on crete tem p era tu res a t t h e tim e o f c a s tin g ; a l s o v a r ie d w ith in
'
■
s
, •■
i .
,,
, ■ ; ■
l i m i t s a s c o n t r o lle d by room tem p era tu re= However^ s in c e th e maximum
'- : .
, ' ■ '■ -
,' 4
J
I
i
i '' I
p o u fih g tem perature was 7U ;Po and t h e minimum was 6 2 °
i t was
th o u g h t t h a t no s e r io u s e r r o r would b e ,in tr o d u c e d by f a i l i n g t o c o n t r o l
p ou rin g tem p era tu res.
' ■' • ’
$he o r i g i n a l p la n f o r t h i s i n v e s t ig a t i o n m s t o u se the. a c c e le r ­
a te d fr e e z in g -a n d 'th a w in g t e s t s . t o d eterm in e t h e d u r a b ilit y o f con crete,
h"':-. '
'
;
a s -'a ffected by a i r tem perature d u rin g j u s t th e Si*. h ou rs a f t e r c a s t in g », .<
A 25. per; c e n t l o s s i n w e ig h t o f th e -specim en was t o have: b een consider-?
; Mvas f a ilu r e o ■ . I t was-assumed by the. author that the freezing would
' T : ' '- ' :
'
.. ''
- " ' .
-have c o n s id e r a b ly more e f f e c t on th e d u r a b ilit y ' th a n i t / h a s , . . Howeverg ,'
a t th e d a te o f i/r r itin g , no I p s s i n w eighty has, been reco rd ed on axij , sp e c ‘: '
‘
’
V‘im en0; : f o r ..th is reason^ .-the.' o r ig in a l,.p la n w as p a r t i a l l y d isca rd ed d ■?- ,1
' v-' .
The p la n t h a t was.1c a r r ie d o u t w h i l e embodying .some f a c t o r s t h a t
were d is a g r e e a b le s was. t h e b e s t co m p ro m ise;th a t.co u ld be d e v is e d ,
',E S s e n tla lly j, i t c o n s is te d , of. w ithdraw ing .one. o f th e, two cu b es o f each -
hatch from the freezin g and' thawing Cycles a t an approximate age of J4.
.
t o 5 m onths.
' ■>
One specim en m s th e n t e s t e d t o f a i l u r e i n com pression
w h ile th e o th e r co n tin u ed in th e f r e e z in g and thawing c y c l e s .
The l o s s
i h d u r a b ili t y a s o f A ugust* 1951s i s th e n t o be d eterm ined b y th e l o s s
i n s tr e n g th o f th e c o n c r e t e , ■f r e e z in g and thaw ing c y c le s w i l l be con­
t in u e d on th e rem aining sp ecim en s t o p r o v id e l o s s in w eig h t d a ta a t a
la t e r d a te,
'
'
,
V-
, T h is method i s u s e f u l i n p r o v id in g some d a ta , on t h e d e tr im e n ta l
e f f e c t o f exp osu re t o le w tem p era tu res o f c o n c r e te i n th e p l a s t i c s t a t e ,
A lth ou gii i t rem oves th e p o s s i b i l i t y o f c h e c k in g •r e s u l t s a s o n ly one
specimen i s tested in each manner * certain trends ar e recognizable, ■
■ ! , He P r ic e 5 "Symposium on F r e e z in g and Thawing T e s t s o f , Con, c r e te " * 'A ,S.T .M , P ro c eed in g s 5 IV I {19b6} 1211).=
•~28-
■
The sp ecim en s Tfvithdrami f o r com p ression t e s t s w ere capped and
t e s t e d i n th e same manner a s th e 6 i n . by 12 i n . cy lin d ers®
As i t has
been fou n d t h a t 6 in ? cubes e x h ib it s t r e n g t h s ,18 p e r c e n t h ig h e r than
6 in® by 12 i n . C y lin d e r s 3^
com pression, s t r e n g t h s Were c e r r e d te d t o
.
a g ree w ith th e stan d ard t e s t c y lin d e r ? , The s tr e n g th s and m is c e lla n e o u s ,
in fo r m a tio n a re l i s t e d in T ab le V.
, ,..The specim ens, f r o z e n w h ile s t i l l i n a .p l a s t i c s t a t e show u&% ,
m ista k a b le marks o f f r o s t c r y s t a l s form ed :d u rin g th e i n i t i a l s to r a g e
■
■
■ .
p e r io d e . (S e e F ig u r e s 2 and 3 ) The ,e x t e r n a l f r o s t c r y s t a l ,p a tte r n s
’
'
' '
o ccu r p red o m in a tely on th e upper h a l f o f th e sp ecim en , th e.am ou n t o f
-
-1
f r e e w a ter a v a ila b le on th e s u r fa c e s o f t h e c o n c r e te presum ably c o n t r o l."I '
,
'•
,
,
. ,; 1 V : ' '
l i n g ’ th e s i z e o f th e p attern s® Th® in t e r n a l; s t r u c t u r e o f th e specim ens
have somewhat th e same appearance®
F r o s t p a t t e r n s were n o te d on^aggre­
g a te exposed, d u rin g t h e com pression, t e s t s a s w e l l a s on th e cement
m ortar i n c o n t a c t w ith th e a g g reg a te ?
I t is , n o ted th a t; f r o s t p a tte r n s
a r e s l i g h t l y more predom inant i n th e m ix es w ith th e h ig h e s t slumps? , .
F r e e z e r tem p era tu res t h a t w ere o n ly a fe w d e g r e e s b elow 3 2 ° F® a ls o
seemed t o fa v o r la r g e c r y s t a l growth more th a n t h e lo w er tem p era tu res«
'
,
. • 1*3................ ' .................. I ,
.............
...... 1..... ^
^ ... - H a rriso n -F =. Qonnerman3 " E ffe c t o f , S iz e and Shape' o f T e st Spec­
imen on Qbmpression .S tre n g th o f G oricrete3" ’ P u b lic Workss Z.VJI (January
1926) 9 31?
,- '
.T ' \
“
'
'
29 -
‘
TABLE V
COMPRESSIVE STRENGTHS OF SIX INCH CUBES
Code
Age
When
T ested
F r e e z in g
and Thawing
C y c le s When
T ested
mo.
IG l
1G2
1G3
IOii
105
106
107
108x
1G9X
IGlX
1G2X
1G3X
IGiiX
IF l
IF 2
1F3
IFii
1F5
IFlX
1F2X
1F3X
IFiiX
1F 5X
5
5
5
5
5
5
5
5
5
5
5
5
5
ii
U
ii
ii
ii
ii
ii
ii
ii
ii
50
50
50
50
50
50
50
50
50
50
50
50
50
IiO
UO
IiO
iiO
IiO
iiO
iiO
iiO
IiO
IiO
O r ig in a l
Weight
W eight
When
T e ste d
kg
kg
p si
p si
8 .3 5
8 .2 9
8 .5 8
8 .3 1
8 .3 5
8.1i3
8 .3 8
7 .8 5
7 .7 6
8 .2 k
8.iiO
8 . Ik
8 .3 8
8 .5 9
8 .5 8
8 .5 9
8 .7 9
8 .5 7
8 .3 8
8 .2 6
S.iiii
8 .5 7
8.iiO
S.iiii
8 .ii3
8 .7 1
8 .k 6
8 .ii6
S.iiii
S.iiO
7 .8 8
7 .8 0
8 .2 9
8 .5 0
8 .2 3
ii050
iillO
3390
3600
U020
ii900
5130
3520
3k60
2920
31k5
2990
2930
3510
35UO
3750
5020
2360
35kO
3kOO
3620
iiSlO
2700
3li30
3ii80
2870
3050
3U00
U150
k3iiO
2980
2930
2ii70
2670
2530
2ii80
2970
3000
3180
ii260
2000
3000
2880
3070
U080
2290
8.51
8 .6 9
8 .5 9
8. 72
8 .8 6
8 .6 1
8 . Ul
8 .3 7
8 .5 7
8 .6 5
8.U 5
Com pressive
S tren g th
Com pressive
S tren g th
A d ju sted to
6 x 12 q y ls .
-3 0 -
F ig u r e 2 .
E x te r n a l f r o s t c r y s t a l p a tte r n on s i x in c h cube s u b je c te d t o
f r e e z in g tem perature w h ile s t i l l p l a s t i c .
-3 1 -
"32—
• BtfERHlEBTION. OF RESULTS
As a' consequence o f th e method Of t e s t f i n a l l y adopted* th e
r e s u l t s cannot tie in t e r p r e t e d 1t o p r e d ic t e x a c t l y th e a c t io n o f f r e e z in g
on f r e s h con crete=
However* a s p r e v io u s ly m entioned*1'c e r ta in tren d s
are' reddily d is c e r n ib le t b p r o v id e some knowledge o f fh e e f f e c t o f th e
fr e e z in g = r ,F ig u res ks ;5s 6* and 7 show th e r e s u l t s o f th e com pression
t e s t s o f th e cubes ( s e e T a b le V) i n g r a p h ic a l form p l o t t i n g a d ju sted ,
com p ressive s tr e n g th i n pounds p er square in c h a t $ months f o r B elgrade
a g g r e g a te sp ecim en s and 'k months f o r Canyon F e r r y a g g r e g a te specim ens
a s o r d in a te and i n i t i a l f r e e z e r tem p eratu re i n d e g r e e s F a h r e n h e it as'
a b s c is s a »
'
'
'
A ls o p lo t t e d ,o n f i g u r e s t th rou gh 7 i s th e e x p e c te d s tr e n g th o f
t h e c o n c r e te a t a g e s o f $ months and k months ( f o r B elg ra d e a g g r e g a te
sp ecim en s# and Ganyon:Ferzy a g g r e g a te specim ens*, r e s p e c t iv e ly = )
These
v a lu e s correspon d t o th e s tr e n g th s o f c o n c r e te cured n o rm a lly f o r th e s e
p e r io d s o f time=
t h e s e . ages=
B o1specim ens w ere C a st f o r com pression t e s t i n g a t
However* an in t e r p o la t io n o f th e r e s u lt s * o f th e R eport o f
th e D ir e c to r o f R esea rch o f t h e P=G=A= 1928 s u g g e s t s .v a lu e s o f 156 p er
c e n t o f 28 day s tr e n g th f o r 5 month specim ens* and 1U8 p e r ,cen t fo r k
month specimens'*.;^.
The v a lu e s p lo t t e d on; th e cu rves a r e computed from
t h e s e p e r c e n ta g e s a n d .th e a v era g e 28 day s tr e n g th o f s i x ‘in= by tw elv e
in= c y lin d e r s =
,
,
............................. ........ . ......................................................................... ........................... .
13
, lit= Q=. W ithey and JameS A ston* J o h n so n 's M a te r ia ls o f Con­
s t r u c t io n * ( 8 t h Od=I New Xorks John W iley and Sons* 19^6)* H^ti-ROO=
.
-33-
•H
M
Q.
S month axpiected s tr e n g t h
I
U630 Ps i
5
S
M
-P
LI
UJ
0)
W
§•
O
O
3000
-
0)
-P
W
d
-a
TJ
To 0 p s i
2000
I n i t i a l F r e e z e r T em perature - D eg. F
F ig u r e 2 .
C om pression r e s u l t s on t e s t cu b es u s in g B e lg r a d e a g g r e g a te
w ith no a i r - e n t r a i n i n g a g e n t ad u ed .
-H
K i
ct
i
-C
5 month e x p o r te d s t r e n g t h I^lBO p s i
S
g
a>
-5
CO
W
<D
O
i
P
S
•ri
TJ
C
•*
#
2000
I n i t i a l F r e e z e r Tem perature - D eg. F
F ig u r e 3»
C om pression r e s u l t s on t e s t c u b e s u s in g B e lg r a d e a g g r e g a te
w ith an a i r - e n t r a i n i n g a g e n t ad ded.
A d ju ste d C om pressive S tr e n g th - p s i
o r e n g tn
k m oith - $190 p | i
-
—
--
To 0 p s i
A d ju ste d C om p ressive S tr e n g th - p s i
£
I n i t i a l F r e e z e r T em perature - D eg. F
ure k .
C om pression r e s u l t s on t e s t cu b es u s in g Canyon F e r r y a g g r e g a te
w ith no a i r - e n t r a i n i n g a g e n t ad ded.
tr e n g th U mopth - I167 O pjsi
To Q p s i
I n i t i a l F r e e z e r Tem perature - D eg. F
F ig u r e $ . C om pression r e s u l t s on t e s t c u b e s u s in g Canyon F e r r y a g g r e g a te
■ w it h an a i r - e n t r a i n i n g a g e n t ad d ed .
From t h e s e C urvesjl i t i s se e n t h a t th e com p ressive s t r e n g t h o f
th e 6 i n o cubes i s sm a lle r in a l l c a s e s th a n t h a t o f n o rm a lly cured
c o n c r e te w it h v a lu e s o f 5 t o 50 p er c e n t l e s s .
The n e x t problem t h a t a r i s e s i s how much o f th e d e tr im e n ta l
e f f e c t can b e a t t r ib u t e d t o t h e i n i t i a l s to r a g e tem p era tu re, and how
much t o th e su b seq u en t f r e e z in g and th aw in g c y c l e s 0
The problem i s by
no means a sim p le one a s many f a c t o r s can in f lu e n c e th e r e s u l t .
i t can be a tta c h e d i n t h i s m anner.
However,
I t i s g e n e r a lly a g reed b y m ost au­
t h o r i t i e s t h a t c o n c r e te poured a t 5 0 ° F„ or h ig h er s u f f e r s n o i l l e f f e c t '
due t o tem perature p r o v id in g i t i s g iv e n su b seq u en t good c u r in g .
The
h i g h e s t ^ i n i t i a l s t o r a g e tem perature g iv e n c o n c r e te sp ecim en s i n t h i s
stu d y was i*5° F=
S in c e t h i s ii.5° F . tem p eratu re i s n o t f a r d i f f e r e n t
from t h e s u g g e ste d 5 0 ° Fe minimum, i t Can p rob ab ly be s a f e l y ,assumed
t h a t any c o n c r e te g iv e n an i n i t i a l s to r a g e o f 2k hours a t
^,,Vand'
su b se q u e n tly g iv e n 27 days, o f m o is t c u r in g a t 70° F 9 w i l l n o t be a f f e c t ­
ed by th e i n i t i a l s to r a g e tem p era tu re?
T h is assum ption i s fu r th e r
str e n g th e n e d by th e f a c t t h a t th e f r e s h l y poured c o n c r e te h a s a tempera­
tu r e o f a p p ro x im a tely 7 9 ° F 9 and a c o n s id e r a b le p e r io d o f tim e la p s e s
b e fo r e t h e c o n c r e te r e a c h e s 1*5° F ,
, J f t h i s assum ption h o ld s t r u e , i t f o llo w s t h a t th e d e tr im e n ta l
e f f e c t o f th e com pleted f r e e z in g and thaw ing c y c le s o n ly on th e s p e c i­
men s to r e d a t h5° F , Can be approxim ated b y -measuring th e d if f e r e n c e i n
s tr e n g th s o f th e 6 i n , cube com pression specim en i n i t i a l l y s to r e d a t k$°
Fe, and t h e s t r e n g t h o f n o rm a lly Cured c o n c r e te o f th e Same S g e 9
The p r o p o r tio n o f t h e d e tr im e n ta l e f f e c t t o b e a t t r ib u t e d t o - t h e
i n i t i a l , s to r a g e .tem perature'.and t o . t h e su bseq u en t freezin g 'a n d " tW tv in g ' p y c le s i s . -somewhat more C om plicated f o r t h e specim ens s u b je c te d t o frees-#in g i tem p eratu res w h ile' s t i l l p la s tic = - . f o r t h i s p u rp o se # ' s i x 6 i n , cubes
'
'
I
’
• r
'
.
,
‘
■"
t
’
i
"
w ere c a s t and p la c e d i n tiie f r e e z e r a t W* F= im m ed iately a f t e r c a s t in g
f o r a p e r io d o f 2k hours=
Thqy were su b se q u e n tly g iv e n 7 d a y s o f cu rin g
in ' th e m o ist c l o s e t and th e n t e s t e d td f a i l u r e i n co m p ressio n =■ The sp ec?
!mens w ere made from ’ B elg ra d e a g g r e g a te w ith o u t a ir -e n tr a in m e n t u sin g t h e
same p r o p o r tio n s a s i n o th e r mixes=
Fr1Om t h e s e s tr e n g th s end th e
S tr e n g th s o f norm ally. Chred c o n c r e te g t h e l o s s i n s t r e n g t h due t o th e
i n i t i a l s to r a g e teKp'erature’' can b e determ ined=
The a v e r a g e 7 day co m p ressiv e s t r e n g t h o f the" s i x 6 in=' cubes
i n i t i a l l y , s u b je c te d t o 8 ° Fi= was l 6 l 5 p si=
The s tr e n g th c o r r e c te d t o
norm al 6 in= by 12 in= c y lin d e r s i s 1370 p si=
A g a in / r e f e r r in g t o a
p r e v io u s report^^^ a ;? day specim en has. a s tr e n g th o f $9 p e r 'c e n t o f a
28 day s p e c im e n / w h ile a f iv e ' month specim en e x h ib it s a s t r e n g t h o f 1^6
p e r c e n t o f a 28 day, specim en=
T h e r e f o r e / p r o j e c t in g th e 7 day s tr e n g th
to a comparable fiv e 'm o n th 'S tr e n g th ,■t h e 6 in= cu b es would show a
S tr e n g th o f 3620 p s i a t f i v e months =
By p l o t t i n g t h i s v a lu e on. F ig u r e 2 and co n n ectin g i t t o th e
p o in t o f no l o s s i n s tr e n g th due t o i n i t i a l S to ra g e tem p eratu re ( s p e c i­
men a t k$° F =) s t h e p r o p o r tio n o f th e d e tr im e n ta l e f f e c t t o be a t t r ib u t e d
t o th e i n i t i a l s to r a g e tem p eratu re and th e su b seq u en t f r e e z in g and thaw­
in g c yKrc -l e s can b-e. / , y determ
ined r;;-T
f o r ea ch i n i t i a l sV'tol'' "dnr
r a g e tem p''"Tera
tu re,
r , ti..iL " J 1F " v i; '
-r \ ''
'V l r -
T -J r rm .-, "i/i,.
^ I b id =
'
'
• '
,
*“ -■Tffy-- t - v r “
-3 7 l^ hus5.-the o r d in a te above: t h is , l i n e and below th e, e x p e c te d S--
,■
m onth.s tr e n g t h .r e p r e s e n ts t h e 'l o s s i n s t r e n g t h due t o t h e i n i t i a l storage'^
w h ile t h e o r d in a te b elo w t h i s l i n e and above, t h e , p lo t t e d v a lu e s rep re~ , ;
SehtS- th e l o s s in s t r e n g t h ,d u e 'to th e 30 fr e e z in g , and thaw ing <^rcleso
T h ese v a lu e s a r e a l l on th e b a s is o f S m o n th ? to ta l a g e . sp ecim en s
''
B y - com putation from t h e a b o v e, t h e f r o z e n sample's w ould e x h ib it
Z1
ap p roxim ately 79 p e r \c e n t o f th e; str e n g th , o f n o rm a lly cu red ; c o n c r e te o f ■
t h e 'Same age*.
.
, ,■■ ■
.
-
■■
•,,,
' -The' p r o p o r tio n o f th e d e tr im e n ta l e f f e c t t o be a t t r ib u t e d t o th e
i n i t i a l . s to r a g e temperature o f 8° F<> f o r t h e specim ens ■made w ith B elgrad e
\ a g g r e g a te w ith a ir -^ it r a in m e n t j and Oanyon F e r r y a g g r e g a te w ith , and -with­
o u t a ir -e n tr a in m e n t w i l l b e . tak en a s the. sa m e,a s above=
W h ile ,,th is 79
per c e n t v a lu e w i l l n o doubt b e approxim ate f o r th ese, sp e c im e n s, i t
sh o u ld b e s u f f i c i e n t l y c l o s e t o e n a b le s a t is f a c t o r y c o n c lu s io n s t o be.
drawn=,
T h e r e fo r e , F ig u r e s ,3, Us and,3 are com pleted u s in g t h i s p e r c e n t­
a g e V a lu e0i .
...
. ,
T t i s i n t e r e s t i n g t o note from Figures 2. through 5. t h a t , in ; e v e r y
c a s e , sp ecim en s ex p o sed t o an i n i t i a l , ,sto ra g e tem perature o f about 3 2 ° F °
e x h ib it e d lo w er s t r e n g t h s th a n th ose: exposed, t o any. o th e r tem perature= N •
l h i l e an e x a c t e x p la n a tio n i s n o t read ily a v a i l a b l e , several ,co n d itio n s
e x is t t h a t c o u ld ca u se th e extreme- r e d u c tio n a t - th is, .tem perature=,, The
fo rm a tio n o f i c e , c r y s t a l s on. th e i n t e r i o r s u r f a c e s o f th e aggregate, and
t h e m ortar i n c o n ta c t w ith th e. a g g reg a te, c o u ld m a t e r ia lly red u ce th e bond
betw een th e m ortar and t h e ,a g g r e g a t e , e n d # i n ,so d o in g , f h e s tr e n g th
WQuld be .reduced*
W h ile , t h is - a p p l i e s ?t©s a l l -specim ens - s u b je c te d t o
. .•
f r e e z in g tem peratureSg the. c o n d itio n s ,o f tenperature., c lo s e .,t o . 3 2 ° Pe V .
,
.fa v o r s th e ,growth o f ■l a r g e ■c r y s t a l s and ,w ould.A ggravate, th e, .red u ctio n s ,
in . b o n d ., A [Second .e x p la n a tio n ,could be t h a t - s h e e t i n g , sp ecim en s to. ,
,
tem p eratu res c f o s e .f o =3 2 ° F® .would ^a llo w t h e ,con crete t o g a in i t s i n i t i a l
s e t b e f o r e i t , w a s f u l l y fr o z e n ..
T h is a cc o r d in g t o A®,
.'41co n d itio n - t h a t s e r io u s ly ,r e d u c e s.,th e s t r e n g t h , ,
15lG unaberg5
Sp0 C itb 5 p , 207=
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c o m u s io M s
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' ■' « S e v e r a l c o n c lu s io n s o m tie ' d r a w from ' th e .'fo reg o in g r e s u l t s »;
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( I ) P i f i y 'f r e e z in g and' tihavrajig c y c l e s 1red u ce t h e ''com preasive
stirengtihs j 'to 28 p er c e n t o f ' th e strength.' 'of ■norm al u n fro zen O eticrete0 ■
"
( 2 ) In g e n e r a l^ th e fr e e z in g , and thaw ing c y c le s .c a u s e d approx*
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Im a tely th e .same n e t l o s s i n s tr e n g th ' r e g a r d le s s ' ©f t h e ' i n i t i a l s to r a g e '
temperattire t o which' the sp ecim en s w ere
,, ,
S U tijected 0 '
■ '- ‘
'
( 3 ) A f t e r t h e f r e e z in g and thaw ing c y c l e s w ere d isc o n tin u e d # th e
sp ecim en s s u b je c te d t o i n i t i a l s to r a g e tem p era tu res o f a p p ro x im a tely 5 ° Fo
i1
e x h ib it e d s t r e n g t h s o f 75 p o r c e n t o f th e •s tr e n g th s o f th e specim ens e x ­
p o sed t o A5° Fb i n i t i a l s to r a g e '^
’
( 4 ) S u b je c tin g th e sp ecim en s t o tin i n i t i a l s to r a g e tem perature
,
'
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i
;
o f a p p ro x im a tely 3 2 ° F= i s t h e w o rst c o n d it io n t h a t can o c c u r 0
From t h e above c o n c lu s io n s # i t can be seen t h a t c o n c r e te p la c e d
i n th e f i e l d a t a i r tem p eratu res som ew hat'below 3 2 ° Fo can tie ex p ected
t o a t t a i n a t l e a s t 70 p er c e n t Of th e str e n g th ' o f n orm ally cured conpreteo
The c o n c r e te s o exp osed can tie ex p ecte d t o r e s i s t f r o s t a c t io n q u ite w e l l
a s f i f t y c y c l e s o f th e a c c e le r a t e d f r e e z in g and' thawing t e s t s ' corresp on d s
r o u g h ly t o : te n y e a r s o f s e r v ic e i n th e f i e l d f
■
S in c e e x a c t information i s n o t a v a i l a b l e s'‘c o n c r e t e :placem ent :
■sh o u ld tie suspended when "the a ir tem p eratu re approxim ates 3 2
i
io u s damage may tie-- done t o t h e f r e s h c o n c r e te »■
F o1 a s s e r ■
•
•\ ■
.The above c p n e lu s io n s can be c o r r e la t e d w ith th e p r e v io u s work
o u t lin e d i n t h e e a r ly p a r t o f t h i s t h e s is * i f th e v a r y in g c o n d itio n s ,
under w hich th e 'p r e v io u s work was com pleted i s k ep t in m ind.
Inasmuch,
a s a s iz e a b l e f a c t o r o f s a f e t y i s in v o lv e d i n th e, d e s ig n o f a c o n cre te
s tr u c tu r e * i t i d p o s s i b l e t h a t th e c o n c r e te could, s u f f e r a 21 per, c e n t
lo s s , i n s tr e n g t h and s t i l l r e t a i n a h ig h enough u ltim a te s t r e s s t o rem ain
c o m p le te ly W ith in th e s a f e w orking r a n g e .
T h is co u ld b e th e s i t u a t io n
w ith ithe r e p o r t s made by A , BU Guntberg and ,Ho Go W atts c i t e d p r e v io u s Iyo
The e x p e r ie n c e c i t e d by Eo A= Hagy i s a s l i g h t l y d i f f e r e n t cond­
i t i o n * s in c e he o b v io u s ly d is tu r b e d th e p l a s t i c c o n c r e te an making ,new
te s t, c y lin d e r s ,
Ho Ho S c o f i e l d r e p o r te d t h a t c o n c r e te f r o z e n im m ed iately
a f t e r c a s t in g a t t a i n s on t h e a v era g e o f ab o u t f>0 p er c e n t o f th e s tr e n g th
o f th e norm al u n fro zen c o n c r e te a t th e same age:,; The v a lu e o f ^O'p er­
c e n t l o s s i n s tr e n g th corresponds, t o th e maximum v a lu e o f 21 p er c e n t
l o s s fou n d i n t h i s s tu d y .
However* a 29 p e r c e n t d iv e r g e n c e i s p o s s ib le
depending on th e r e l a t i v e s e v e r e n e s s o f th e t e s t s 0 '
I
,
A more a c c u r a te and com p lete c o r r e la t io n o f r e s u l t s m ight be
drawn i f d e t a il e d d e s c r ip t io n s o f each t e s t were, .a v a ila b le 0
S in c e none
a r e a v a ila b le * an approxim ate c o r r e la tio n * su ch as, t h e one above* i s a l l
t h a t can be drawn,o
"r-ijlj!*.
SUGGESTIONS FOR,FtETHER.STUBY
The au th or w ould l i k e , t o ta k e t h is , o p p o rtu n ity t o s u g g e s t p o s s J
I b le o th e r p h a s e s ,o f stu d y ,in th e same T ie ld 0 .
■
■
, The p e c u lia r a c t io n ,o f concrete when exp osed t o tem p eratu res o f
approximately 3 2 ° Fo ,in d i c a t e s f u r t h e r s t u d y . i s ,needed t o p r e d ic t the. ■,
c o n c r e te s tr e n g th and d u r a b ilit y exposed t o tem p eratu res in t h is , rangev .
, A s t u d y ,o f th e a c t io n , of. c o n c r e te exp osed t o c o ld tem p eratu res
.
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a f t e r t h e c o n c r e te h a d .a t t a in e d i t s , i n i t i a l o r f i n a l s e t w ould be valu­
able i n com p letin g d ata, p u t fo r t h , by t h is , stu d y and th e, above m entioned
Snggestpd Study0.
,
t
APjRSIEJiX A
C o n sid e r a tio n s In v o lv e d i n t h e Making o f F r e e z in g
,.
and Thawing T e s t s on C oncrete
The numerous a lt e r n a t io n s ©f f r e e z in g and thaw ing (O ften 2$ t o W
-• y .
. . .
'
.
p er annum) i n th e c lim a te o f th e tem perate zo n es cau se d e t e r io r a t io n in
a l l p orou s ro ck and masonry s t r u c t u r e s 0
C oncrete i s p a r t i c u l a r l y su scep ­
t i b l e t o t h e w ea th erin g in f lu e n c e s o f n a tu re when su b je c te d t o sev ere e x ,
•
■
posure®
■
.
The a c c e le r a t e d f r e e z in g and thaw ing t e s t grew b u t o f th e d e s ir e
t o know th e r e l a t i v e d u r a b ilit y o f concrete®
I n t h i s t e s t , t h e o b j e c t iv e
h as been t o s e c u r e ^ i n a r e l a t i v e l y s h o r t le n g t h o f t im e , an in d e x o f th e
le n g th o f s e r v ic e w hich may be e x p e c te d when s u b je c te d t o a g iv e n ty p e o f
exposure®
Of t h e a c c e le r a t e d t e s t s th u s f a r t r i e d , th e f r e e z in g and thaw­
in g t e s t , w hich ap p roach es c o n d itio n s i n n a tu r e , has been t h e m ost s a t i s *
factory®
S in c e t h e v a lu e o f th e in d e x o f d u r a b ilit y determ ined from th e
d a ta from a. fr e e s in g -a n d -th a w in g t e s t i s dependent upon th e c o r r e la t io n
.
/
w h id i e x i s t s betw een t h a t in d e x and th e a c t io n o f n a tu r e , t h e t e s t sh o u ld
b e s o d e v is e d t h a t i t w i l l correspon d i n i t s a c t io n t o t h a t o f nature®
^
The o n ly im p ortan t d iv e r g e n c e sh o u ld be t h a t th e t e s t s e t s up a more
r a p id r a t e o f d is in t e g r a t i o n i n t e s t sp ecim en s w ith o u t m o d ify in g th e pro­
c e s s o f d is in t e g r a t i o n accom p lish ed much more s lo w ly by nature®
I t seems ap p aren t from s t u d ie s made t h a t th e d e t e r io r a t in g i n f l u ­
en ce o f f r e e z in g and thaw ing i s in t im a t e ly r e la t e d to*
( I ) t h e perme­
a b i l i t y o f th e c o n c r e te 5 ( 2 ) th e d eg ree t o w hich th e c o n c r e te i s s a tu r a te d
w ith f r e e z a b le w a ter j and ( 3 ) th e amount Of' f r e e z a b le w a ter i n th e e o n -
ere tep
I n tu r n 5 th e s e f a c t o r s w i l l b e m a t e r ia lly in flu e n c e d by th e w a te r -
Cempnt r a tio , of. ,th e . p a s t e , t h e , c h a r a c te r e f .th e a g g r e g a te s th e c o n s is te n c y
Cf th e c o n c r e te , th e c u rin g c o n d it io n s , and th e p ro p o rtio n o f e n tra in ed
a i r i n the' s e t 'cen crete* '
»
T e s t d a ta in d ic a t e s t h a t th e r a t e o f d is in t e g r a t io n o f c o n cre te
in c r e a s e s w ith th e r a t e t h a t th e tem p eratu re f a l l s d u rin g fr e e z in g =
S in c e
t h e f a l l o f atm osp h eric tem p eratu re i n th e v i c i n i t y o f 3 2 ° F= r a r e ly ex­
ce e d 3 9 F= p e r hour* i t d o es n o t appear d e s ir a b le t o lo w er th e tem perature
a t to o f a s t a ra te=
.U n til more d e te r m in a tiv e d a ta a re o b ta in ed * a l i m i t
Of 1 0 ° F.» p e r hour i s su ggested =
The th r e e ty p e s o f f r e e z in g and thaw ing t e s t s commonly u sed are:
1=
-
F r e e z in g immersed i n w a ter and thaw ing submerged in water=
2 o F r e e z in g p a r t ly immersed i n w a ter and thaw ing p a r t ly or w h o lly
immersed i n water=
3=
F r e e z in g in a i r a f t e r s a t u r a t in g i n w a ter and thaw ing su b-
merged’ in water=
I n .e a c h o f t h e s e t y p e s o f t e s t th e r e have b een a g r e a t many v a r i f
th e tem p era tu re,O f t h e 1 specim en when p la c e d i n th e f r e e z e r ,, th e
■
a b le Sg
r a t e o f f r e e z i n g , t h e minimum tem perature a t t a in e d , th e tem perature o f th e
w a ter u sed i n th aw in g,, a n d ■t h e 'r a t e o f thawing=
h ow ever, th e procedure
o f ty p e 3 gave t h e m ost u n iform in d ic a t io n , o f q u a lit y o f t h e co n cretes.
16
:
■'
’
■
1■ - te s te d = .
---------- ~ B —
---------v V 1:....T "
M= 0= W ithey, "C o n sid e r a tio n s I n v o lv e d in th e f a k in g o f F reez=
in g -a n d -lh a w in g T e s t s on Concrete=** A=S=TsM= Proceedings;, JtLfI (1 9 it6 ),
1198-1207=
’
‘ '
'
'' • -
gpetiiroens' W w e d i d w a ter and f r o s e a in w ater e r e a f f e c t e d much "-
m ere by. f r e e z in g a l t e r n a t i o n s »■ The d if f e r e n c e i s ‘thought' t o l i e 'i n t h e
f a c t t h a t im m ersion f o r c e s more w a ter i n t o th e sp ecim en s becau se' o f th e
‘s l i g h t h y d r o s ta t ic head" t o w h ich t h e y a r e su b jected ,, '
V a rio u s schem es f o r r a t in g t h e e f f e c t Of f r e e z in g and thawing" have
b een employed^ in c lu d in g v i s u a l in s p e c t io n s ■change' i n co m p ressiv e Strength*
d e c r e a se i n modulus Of e l a s t i c i t y a s d eterm in ed 'by s t a t i c lo a d in g * change
i n modulus Of e l M s t io it y b y t h e SOhic method* l o s s i n w e ig h t* 1and; change
i n I e n g th 0
-:
"
.
.
^
'
‘
’
'
'
1 \
I ^ B a ile y Tremper*' "Symposuim o n ,F reeain glan d lT h aw iag T e s ts o f
co n crete" * 'AoSoTftMo.' feoC eed in gs.y XLVI (191*6)* 1227-1229<,
(
APEBaDK B'
i Mechanism o f D is in te g r a tio n :
A s :commonly u n d ersto o d and h e r e u sed 3 f r o s t :a c t io n i s t h e break­
down, ©f th e . s t r u c t u r e o f c o n c r e te Caused by! a lt e r n a t e f r e e z i n g , arid thaw in go
She p r e se n c e o f m o istu re i n t h e pore's o f t h e C oncrete i s n e c e s s a r y
f o r f r o s t a c t io n t o .o c c u r and t h e m oistu re,m ay e n te r e i t h e r by c a p illa r y
a c t io n o r p r e ssu r e ,,
„
The .d e te r io r a t io n u s u a lly m a n if e s t s ' i t s e l f , by s c a lin g
and r a v e llin g , b u t i t may o ccu r w ith o u t d o in g ,e it h e r o
'■
1
*
:I h e n c o n c r e te sp ecim en s a re f r o s e n and,.thawed (=,»«». »)» two. d is-6*
t i n e t ty p e s o f d is in t e g r a t i o n have b een observed? ( I ) The specim ens ■
may show l i t t l e change i n w e ig h t and appearance b u t la r g e l o s s e s i n
S tr e n g th and r e s i l i e n c e 3 o r ( 2) th e y may show p r o g r e s s iv e l o s s 'by
crum bling and s p a l l i n g b u t r e l a t i v e l y l i t t l e , l o s s i n s tr e n g th , And,
r e s i l i e n c e o f th e rem ain in g m a te r ia l = T hese are extrem es= Specimens
f a i l i n g i n n e it h e r c a te g o r y w i l l show crum bling and l o s s o f str e n g th
and r e s i l i e n c e o f th e rem ainin g, m a t e r ia l. 10
: ,
A lte r n a t e f r e e z in g And thaw ing o f c o n c r e te i s a c o n tr ib u to r y
r a t h e r th a n a fundamental ca u se f o r i t s d e t e r io r a t io n c The f a c t t h a t
th e tem p eratu re Of c o n c r e te d ro p s.b elo w 3 2 ° Po. h a s no S ig n if ic a n c e in
i t s e l f g f o r d ry c o n c r e te may be f r o z e n and" thawed r e p e a t e d ly w ith
n e g l i g i b l e damage» There must be w a ter in th e p o r e s b e fo r e harm can
r e s u l t from f r e e z in g and i t must b e p r e s e n t in such an amount t h a t
when i t in c r e a s e s in , volume a s i t changes S t a t e 5 t h e i c e formed w i l l
more than f i l l t h e p o r e s c o n ta in in g i t 5 and s o vri.il d e v e lo p d is r u p , t i r e fo r c e s
■,
; , ..
T h is much o f th e f r o s t a c t io n ,on c o n c r e te i s g e n e r a lly a cce p te d
by. a l i o
: Dowever5 th e problem .of. t h e e x a c t a c t io n o f , th e f r e e z in g w a ter
w i t h # th e co n crete, i s s t i l l s u b j e c t t o , some ,c o n tr o v e r s y 0 . Two d if f e r e n t
v ie w s o f th e problem w i l l b e ,p r e s e n te d here=
A ,,R,...C o llin s, rep o rts?
,
' ^ T = G=" PowerSy "A EorKing H y p o th e sis f o r P u r fh e r i S tu d ie s AC F r o s t
R e s is ta n c e , o f C o n c r e te ,” .Am erican ConorOte .I n s t it u t e J o u rn a ls .XLI' (Feb». ’
i
?k $ } s 250-251.
' -l^Ro B o Young," " F r o st1R e s is t a n t C on cretes” Am erican C oncrete
I n s t i t u t e J o u r n a l, ,XXKPI ( A p r il 1 9 h p ), h77°°h90o..
. From, t h e e v id e n c e a v a il a b l e . i t a p p e a r s , t h a t f r o s t damage., in ccO-*
,, cre te, and .o th er .porous m a te r ia ls , i s . due t o the. s e g r e g a tio n , o f i c e
i n t o .la y e r s y r a t h e r , th an .:to th e, sim ple, ex p a n sio n o f .th e fro a en . m t e r .
i n th e p o r e s 0 The mechanism: i s , in . f a c t s . .s im ila r t o th a t , o ccu rrin g
iIn .,s o i l s , d u rin g f r o s t ..h e a v in g «,2P
. % .O o llin s b ased .h is. c o n c lu s io n s , on an a p p lic a t io n o f T ab errS- th eo ry
t o th e f r o s t r e s is t a n c e o f c o n c r e te 0
O o l lin s 8 e x p la n a tio n i s a s f o llo w s :
C o o lin g begins, a t t h e exp osed s u r fa c e and ex ten d s s lo w ly inwards 0
When'any la y e r b elow t h e s u r fa c e r e a c h e s a s u f f i c i e n t l y low. tem pera.t o r e 3 t h e w a ter i n t h e l a r g e s t p o r e s b e g in s t o f r e e z e and th e l a t e n t ,
h e a t g iv e n up by i t te n d s t o m a in ta in c o n s ta n t tem perature a t th e
p o in t p f i c e fo r m a tio n 0 The i c e . c r y s t a l s s o formed a r e i n c o n ta c t
w ith u n fro zen w a ter i n t h e surroundingj> s m a lle r p o r e s g and# b y draw­
in g w a ter from, them# t h e c r y s t a l s eo n tih u e t o grow= , ,
, The f o r c e e x e r te d by i c e w i l l b e p erp en d icu lar' t o t h e c o ld su r­
f a c e ! npd i f t h e c o n c r e te i s Of lo w .str e n g th # a p la n e o f w eakness
p a r a l l e l t o t h e c o ld s u r fa c e w i l l ten d t o form a t t h e l e v e l a t which
, th e i c e i s form in g 0
_
,
The w a ter drawn i n b y th e grow ing c r y s t a l s o f i c e w i l l , come f i r s t
from th e l a r g e s t u n fro zen 'p o resa As t h e s e become em ptied# th e su p p ly
■w i l l be. r e s t r i c t e d and th e r a t e o f g ro w th -o f th e i c e w i l l , be checked^
The e v o lu t io n o f l a t e n t h e a t w i l l n o t th e n be; s u f f i c i e n t t o m ain tain
th e tem p eratu re c o n s ta n t a t th e p o in t o f .ice**form ation and th e temper­
a tu r e w i l l b e g in t o f a l l once moreo
As th e r e i s th en l i t t l e o r no w a ter i n th e l a r g e s t pores: in th e
c o n c r e te im m ed ia tely b elo w th e f i r s t ic e , layer#., f r e e z in g w i l l n ot. .
b e g in a g a in u n t i l e i t h e r th e tem p eratu re has dropped s u f f i c i e n t l y t o
f r e e z e t h e p o r e s t h a t do c o n ta in w ater o r a l e v e l i s rea ch ed where
th e la r g e r p o r e s a re n o t a f f e c t e d by t h e i c e form ing, ab ove them . The
r e s u l t o f t h i s p r o c e s s i s t h a t c o n c r e te w i l l c o n ta in a., s e r i e s o f
p la n e s o f w eakness p a r a l l e l t o t h e s u r fa c e o f cooling,o' During th e
su b seq u en t c y c l e s o f f r e e z in g th e i c e w i l l ,a g a i n te n d t o form a t th e
game l e v e l s As b efo re# b eca u se th e p o r e s th e r e have b een d iste n d e d by
th e p r e v io u s ic e # ,a n d t h e f r e e z in g p o i n t ,o f t h e . w a ter i n them w i l l be
h ig h e r th a n i n th e surrounding c o n c r e te 0 1
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■- The damage t o t h e c o n c r e te i s c o n s id e r e d .to be c a u s e d ,n o t so much
b y t h e a c t u a l in c r e a s e i n , volume o f t h e w a ter In "the p o r e s on f r e e z in g
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C oncrete ,I n s t it u t e J o u r n a l^ XLI (dune 191*1?)# 726-72%. ■
<7a s b y th e -grovrbh o f th e c r y s t a l s a fte r w a r d s and th e con seq u en t se g r e ­
g a tio n and c o n c e n tr a tio n ' o f i c e in t o ' th e l a y e r s . ' '
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One b a s ic d isa g reem en t ap p ears in' th e d is c u s s io n o f t h e aforemen­
t io n e d h y p o th e sis*
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e e e d in g s d f th e Highway R esea rch Boards 1936s shows t h a t in la b o r a to r y
t e s t s th e low er th e r a t e o f f r e e z in g t h e s m a lle r th e d e s t r u c t iv e e f f e c t ,
' whereas' th e O o llir is h y p o th e s is r e q u ir e d t h e 'o p p o s it e r e s u l t * 22 ■■■
■ -
Iri o ffe r in g - some o b j e c t io n s t o t h e Q o llin s h y p o th e sis^ Powers h as
advanced h i s own th e o r y f o r t h e a c t io n o f f r e e a ia g w a ter in ' co n crete*
e s s e n c e , h i s e x p la n a tio n o f th e a c t io n i s g iv e n a s f o llo w s ?
in
C onsider a
; s u r fa c e o f a specim en t h a t h a s been Sn c o n ta c t w ith w a ter f o r some tim e
'p r io r t o th e b e g in n in g o f th e f r e e z in g c y c l e *
The w a ter c o n te n t o f th e
■ c o n c r e te n e a r t h e s u r fa c e i s p rob ab ly a t o r n ea r t o t a l 1s a t u r a t io n , and i s
h ig h er* though perhaps o n ly s l i g h t l y * th an th e a v erage w a ter co n ten t o f
t h e specimen*^; I f 1th e c o n c r e te i s th e n ex p o sed t o a' tem p eratu re ‘low er
-•th an 3 2 ° F » 5 t h i s sh o u ld b e t h e seq u en ce o f e v e n ts * F i r s t s t h e w ater on
■' th e 'su rfa ce f r e e z e s , th u s s e a lin g t h e s u r fa c e o f th e c o n c r e t e | seco n d , th e
w a t e r 'in th e c a p il la r y sp a c e s o f t h e c o n c r e te n e a r e s t th e s u r fa c e w i l l
.f r e e z e 1and a s th e change i n s t a t e t a k e s p la c e * th e s t i l l u n fro zen w ater in
th e. s a tu r a te d r e g io n w i l l b e d is p la c e d tow ards th e l e s s s a tu r a te d in t e r i o r .
I f t h e vw a te r w ere f r e e t o move w ith o u t r e s i s t a n c e , n © 'h yd rau lic
p r e s s u r e w a tev er would d evelop *
However, s in c e th e w a ter i s r e q u ir e d t o
"'Vi'1":-""T"'
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move' th r o u g h ,a f I n e ^ te x tu r e d 5 porou s su b sta n ee5. t h e f o r c e c a u s in g 't h e '
' movement m i l ,g iv e r i s e t o a Oorresponding f r i c t i o n a l r e s i s t a n c e ’ and grad-^
'
1
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"i e n t s o f h y d r a u lic p r e ssu r e w i l l be present during, th e movement o f "the
, _
. w a te r accord in g, t o th e la w s o f h y d r a u lic flow*
I f t h i s r e a c tio n - a g a in s t ■
t h e f o r c e ’d is p la c in g , th e w a ter i s s u f f i c i e n t l y h igh * th en i t can be r e ­
garded a s b e in g ca p a b le o f damaging th e specimen,
■
.
On r e p e a te d f r e e z in g , and. thawing* .th e ■sa tu r a te d - r e g io n n ea r th e.
s u r fa c e sh o u ld in c r e a s e in th ic k n e s s .a c c o r d in g , t o th e amount o f w ater
ab sorb ed by t h e s p e c i m e n As th e th ic k n e s s o f t h i s r e g io n in c r e a s e s *
th e 'r e s is t a n c e t o >,d isp la cem e n t -of' water o u t o f t h a t 1r e g io n tow ards - th e
r e g io n o f low er water c o n te n t w i l l 1--increase-*- and when th e s a tu r a te d
-
r e g io n -be'cOmeb s u f f i c i e n t l y t h i c k the h y d r a u lic p r e s s u r e w i l l become
-g rea ter th a n t h e s tr e n g th o f . th e -m a teria l and ca u se d is in t e g r a t io n - or
s p a l l i n g 0,
-
■
,•
Powers g iv e s a method f o r e s t im a t in g th e p o s s ib le h y d r a u lic d i s ­
r u p tiv e fo rce* , b u t i t w i l l n o t b e d is c u s s e d h ere 6 ', However* he s t a t e s
th a t" th e h y d r a u lic p r e ssu r e w i l l 'depend on t h e p e r m e a b ility o f th e m ater­
i a l th rou gh w hich w a ter m ust f lo w t o e sc a p e from th e s a tu r a te d reg io n *
''
V ,
and th e r a t e o f I r e e z in g 023 ,
■I t m ust be s t r e s s e d t h a t n e it h e r o f th e above m entioned hypothe­
s i s a r e g e n e r a lly a c c e p te d .
M eith er h a s i t been meant t o i n f e r ’th a t th e s e
a r e th e o n ly h y p o th e s is on th e a c t io n o f f r e a s in g w ater in c o n c r e te »
-Howeyer5 th e s e t w o . sam ples sh ou ld se r v e t o g iv e, -th e r e a d e r some knowledge
o f th e th eo rie s,, in v o lv e d and th e problem s en co u n tered .
23 z b id . 2 2 1 - 2 # .
’
LITERATURE GlTBD A S) CONSULTED
B atciieM eP 9, W= Ho '1928
EnglneerAhg■
»
Bateman9 John Ho , 195U M a ter ia Ie o f C o ttstrn etio n a Pitm an P u b lish in g
C orp oration # T oron tb i
.■
B aner9 Edward Ao
New-Iorko
1949
P la in ,C oncretb 9 M cGraw-Hill Book Company, 'Zndo9
■-r
C o l l i n s 9 A# :Ro
1945
American C oncrete I n s t i t u t e J o u r n a lo
Gonnerffibh9 H a rriso n Fo
G hhsberg9- A i Mo
1931
Hagy9. E». a :» .. 1942
Pow ers,; Tc Co
P r i c e , We Ho
1926 . P u b lic Works,. ' .
E n g in eer in g Hews0
Am erican C oncrete I n s t i t u t e J o u rn a l.
1945
1946
American, C on crete I n s t i t u t e J o u r n a ls
A.. 8 . 1 . M. P r o c e e d in g so
SCOfi b i d , He Ho
1937
Tremper9 B a ile y
1946 ■A»SoToM.. P r o c e e d in g s* ,
' '
'
Watts,-, Ho1. Go
C o n crete.
'
1942
1
t
American C oncrete M s t i t u t e J o u rn a l.
W ith ey9 Mo O= and A sto n 9 James 1946 J o h n so n 's M a te r ia ls o f C o n strn ctio n 9
: John W il^ r 'and S on s9 New I p r k . '
■
W ith er, ’I . Oft
1946
AoB.,TJL P r o c e e d in g s.
Io n n g 9 Ho Be
1940
American C oncrete I n s t i t u t e J o u rn a l.
Ib n h g 9 Be Bi,
1942
American Concrete I n s t it u t e Journal.
103328
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MONTANA STATE UNIVERSITY LIBRARIES
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