Concrete is one of the most used materials in construction and
engineers have worked to ensure
concrete responds to new requirements related to environment
protection [
1
,
2
]. Production of cement,
an important component of concrete, is a cause of CO
2
emission (7%), and the huge quantities of natural
aggregates used in the concrete composition result in important
changes in the natural environment.
Non-conventional concretes, with different types of materials in
the mix, have emerged just for partially
eliminating the above ecological problems. The cement is replaced
partially or totally by different
materials, such as fly ash, silica fume, slag, rice husk and banana
leaves ash [
3
–
8
]. Aggregates have
been replaced by steel slag, chopped plastic bottles, polystyrene
granules, recycled aggregates, chopped
sunflower, etc. [
9
–
13
]. Fibers of diverse types have also been added in the concrete
mix: steel, polyester,
hemp, etc. [
14
–
18
]. The main objective of the article was to analyze the behavior
of hollow blocks
manufactured with concrete prepared with a cement substitution
with fly ash and waste types such
as chopped plastic bottles and wood waste as replacements for sort
0–4 mm and polyester fibers as
a dispersed reinforcement. The hollow blocks manufactured with
non-conventional concretes will
be used to make a non-load-bearing masonry wall. In the next stage,
this masonry wall will be built
and tested.
2.1. Materials
In the research, a control mix of concrete (C
0
) was used for preparing hollow blocks which had the
following components: cement type CEM I 42.5 R [
19
] in a dosage of 360 kg/m
3
; and river aggregates
in three sorts, namely 0–4 mm, 4–8 mm and 8–16 mm, which were in
the following dosages: 803 kg/m
3
of sand, 384 kg/m
3
of sort 4–8 mm and 559 kg/m
3
of sort 8–16 mm. We used water in a dosage of
172 L/m
3
, and 10% of the cement dosage was replaced with fly ash, from CET
Holboca Iasi. Fly ash
Proceedings
2020, 63,
79;
doi:10.3390/proceedings2020063079
www.mdpi.com/journal/proceedings
Proceedings 2020, 63, 79 2 of 6
was used before in other experimental tests and presented by the
authors in [
15
,
20
]. Waste types PET
bottles and wood waste were chopped into sorts of 0–4 mm and used
as replacements for 20% by
volume of the dosage of aggregate sort 0–4 mm in the case of PET
and 40% by volume of the dosage of
the same aggregate sort in the case of wood. The chopped PET and
wood waste had sizes between
0 and 4 mm. Waste from polyester fibers was used, which was cut
into 30 mm-long filaments and
dispersed as a replacement reinforcement in the concrete, in a
dosage of 0.25% of the concrete weight.
In the mixture, we used a superplasticizer (Master Glenium SKY 617
from BASF) in a dosage of 1% of
the cement volume.
2.2. Samples
The control mix of concrete (noted C
0
) and the mixes with fly ash and chopped PET (noted
C
1
), fly ash and wood waste (noted C
2
) and fly ash and polyester fibers (noted C
3
) were prepared
by mixing all the components. The wood waste was moistened before
being added to the mix.
The samples were poured: cubes of 150 mm in size for determining
the compressive strength fc, and
prisms of
100 × 100 × 500 mm
in dimension for determining the flexural strength f
ti
and split tensile
strength f
td
[
21
–
23
]. The hollow blocks, one of which is shown in Figure 1, labeled
HBF1–HBF3 were
manufactured only for the concretes with waste (concretes C
1
–C
3
). After 24 h, the specimens were
removed from the formwork and kept in the laboratory at a
◦
temperature of 20 C until testing
https://www.researchgate.net/publication/349146869_Experimental_
Study_on_Hollow_Blocks_with_Wastes
https://www.ijert.org/research/a-review-study-on-differentproperties-of-hollow-concrete-blocks-IJERTCONV4IS03032.pdf
NTRODUCTION The basic requirement of human being is shelter. In ancient time human starts living in
caves below ground level, after that they started constructing walls from mud, they developed the
techniques of burnt clay brick masonry for making the structure part of the shelter. Now days, hollow
concrete blocks are being very popular in construction. These blocks are being mostly used in the
construction of multi storied buildings, factories and residential buildings. These concrete hollow blocks
are commonly used in compound walls because of cheapness. These concrete hollow blocks are more
useful due to its lightweight and the most important feature is ease of ventilation. The concrete hollow
blocks are made out of mixture of cement, sand and stone chips. It reduces cement in masonry work and
reduced the cost of construction. The hollow concrete blocks found out due to different advantages1.
Sound control 2. Small dead load 3. Resistance to fire 4. Adequate strength 5. Superior thermal insulation
6. Economy 7. Highly durable 8. Environmentally Eco friendly 9. Reduction in mortar consumption 10. Fast
and Easier construction system 11. Better Architectural features The first Concrete block as a replacement
for stone and wood in the building was used in the United States. The first concrete block house built up
in 1837 on Staten Island in New York. Harmon S. Palmer, designed first hollow concrete block in 1890.
Palmer patented the design of hollow block in 1900 after 10 years of experimental research. Palmer’s
blocks were 8inch(20.3cm)×10inch(25.4cm)×30inch(76.2cm) and they were heavy in weight. These early
hollow blocks were cast by hand and average output was about 10 blocks per hour. Now concrete blocks
are manufacturing by automated process that can make up to 2000 blocks per hour. The Compressive
strength of masonry is one of the most important property in the design of masonry structure. This
strength depends upon several factors such as unit strength, mortar strength, grouting, grout strength,
geometry of the blocks, bedding mortar, and the type of bonding and bedding arrangements adopted. In
extreme hot or cold climate countries these concrete blocks possessing low thermal conductivity and also
serve as a thermal insulation material which minimize the energy consumption by minimizing the
dependence on electricity for air conditioning or heating. In all countries, the different conventional
materials are replacing to the concrete hollow blocks because most conventional materials cost is
increasing. In the review study we found that hollow blocks of double H shape gives more strength with
semigrouted masonry and low strength with fully grouted masonry
LITERATURE REVIEW H. S. Sureshchandra, G. Sarangapani, and B. G. Naresh Kumar(2014)[1] find out the
compressive strength of hollow blocks with partial and full replacement of sand by quarry dust. After
replacement he found that 50% replacement of sand gave high strength and 100% replacement of sand
gave low strength. Ernesto S. Fortes, Guilherme A. Parsekian, and Fernando S. Fonseca, A.M.(2014)[2]
studied the compressive strength of ungrouted, grouted masonry and masonry units. This research work
indicate an increase in the compressive strength of the masonry with increasing compressive strength of
the units. Liang Huang, Lejia Liao, Libo Yan, S.M. and Hongwei Yi(2014)[3] studied the compressive
strength of double H concrete block masonry prisms under uniaxial compression. He discussed the effects
of mortar strength, grouting and grout strength effect on compressive strength of the prism. The test
result shows that the compressive strength of H block prism decreased with an increase of grouting and
the ultimate load of the prisms increased greatly. K. S. AlJabri, A. W. Hago,R.Taha, A. S. Alnuaimi and A. H.
AlSaidy(2009)[4] makes the block with waste materials: vermiculite and polystyrene which were used as
light weight aggregates and cement kiln dust (CKD) which was the partial replacement for cement. The
result shows that the light weight concrete blocks manufactured from polystyrene had International
Journal of Engineering Research & Technology (IJERT) ISSN: 2278-0181 Published by, www.ijert.org RACEE
- 2015 Conference Proceedings Volume 4, Issue 03 Special Issue - 2016 1 low thermal conductivity than
vermiculite and ordinary concrete blocks and the addition of up to 15% CKD as cement replacement gives
a negligible effect on the strength. Denise S. Sanchez and Lisa R. Feldman(2014)[5] determined that
calculated tensile resistance of the reinforcement was greater for bars that were in contact and
furthermore is in sensitive to the magnitude of the transverse spacing provided in the case of noncontact
lap splices. Thaniya Kaosol (2010)[6] has made study on the reuse of concrete waste as crushed stone for
hollow concrete masonry units. The main objective was to increase the value of the concrete waste, to
make a sustainable and profitable disposal alternative for the concrete waste. Attempts were made to
utilize the concrete waste as crushed stones in the concrete mix to make hollow concrete blocks. Various
percentages of crusted stones have been tried the amount (i.e. 0%, 10%, 20%, 50% and 100%). From the
results they found concrete waste can used to produce hallow concrete block masonry units. M.K.
Maroliya(2012)[7] found that the crack patterns developed in the structural elements such as wall and
the strength of wall constructed with hollow concrete block gives the less strength as compared to bri
https://www.irbnet.de/daten/iconda/CIB_DC26900.pdf
https://www.journalcra.com/article/comparative-studycompressive-strength-concrete-hollow-blocks-using-river-and-seasands