 It is the form of Silica .It is formed by decomposition of sandstones due to various weathering effects.
 Fine minerals
 The order of 0.1 to 1.0 mm diameter
 Fill voids between the coarser aggregate
Types of Sand
1) Natural Sand – obtained from pits, shores, riverbeds seabed's…
2) Artificial Sand – obtained from crushing of stones.

Types of Sand (depending on fineness)
1) Coarse Sand – retaining on sieve 4.75 mm
2) Fine Sand – passing through sieve 4.75 mm
Uses
1) PCC, RCC, PSC
2) Cement mortar, Lime Mortar
3) Coarse Sand - plaster on Ex. Wall, Fine Sand – Plastering on
Internal Wall
4) Below flooring material
5) In filtration plant.

Cheapest, Durable and obtained from ROCK
Properly dressed and shaped before it is used.
 Classification of Rocks
1) Geological – Igneous Rock, Sedimentary & Metamorphic
2) Physical – Stratified, un-stratified and Laminated.
3) Chemical – Siliceous, argillaceous, calcareous
4) Hardness of Stone - Very hard, hard, medium, soft

181

•Marble - Exterior
Application
182

•Slate Flooring

•Limestone with Granite

•Granite Material
•Polished Surface
•Rough Texture

 Foundation, roofs floors, railway ballast, road metal.
 Stone Blocks – Wall, Foundation,
Ornamental Facial work.
 Slate – Roofing & Flooring
 Lime Stone Slabs – Flooring, paving and roofing
 Granite – bridge abutment, piers, flooring, kitchen otta, steps, table top etc…..
 Marble – floors, tiles,
Ornamental Facial work.

 Steel is an intermediate form between Cast Iron and Wrought iron.
 Steel are highly elastic, ductile, malleable, forgeable, weldable.
Grades of Steel –
Fe250, Fe415, Fe500
Fe = ferrous metal
Number = Yield stress in N/mm²

 Cast iron is iron or a ferrous alloy which has been heated until it liquefies, and is then poured into a mould to solidify.
 Wrought iron is an iron alloy with a very low carbon (0.1 to 0.25) content in contrast to cast iron, and has fibrous inclusions, known as slag. Wrought iron is tough, malleable, ductile and easily welded.
 Malleable is a material's ability to deform under compressive stress.

 Mild Steel -
Used as structural and
Non-Structural Steel, in form of
I, C, L, round, flat shapes.
It is Fe 250 as yield strength is 250 N/mm²
 Tor Steel – used in RCC work,
It has low ductility and low bend ability.
It is Fe 415 & Fe 500 (yield stress)
 High Tensile Steel – usually in form of WIRES of high tensile strength (tendon)
Used in prestress concrete.
1500 to 2350 N/mm² (Ultimate stress)

 Mild Steel  High Tensile steel

 Tor Steel

Uses of Steel
 Structural member in trusses, beams
 Non Structural components for grills, stairs, windows, doors etc ….
 Steel Tanks, Steel Pipes.
 TOR steel in RCC member.
 Tendons in PSC.
 Corrugated sheets as roof covering
 Mild Steel in manufacture of tools, equipments, towers, machine parts etc….

(CEMENT + Fine Aggregate+ Coarse Aggregate
+ WATER)
PROPORTION ( 1:2:4), (1:3:6), (1:4:8)
GRADE M15, M20, M25……. And so on……
M- Mix Number – Compressive strength after 28 days in N/mm²
(A cementation reaction between water and the mineral in cement provide a strong matrix and good compressive strength)
 Common construction material
 Strong hard but brittle

 (PCC) Plain Cement Concrete
 (RCC) Reinforced Cement Concrete
 (PC) Precast Concrete
 (PSC) Prestress Concrete

 PCC – (cement + FA+ CA +Water)
Strong in compression and weak in tension
Hard and Durable
Manufacturing – Hand mixing or Machine Mixing.
USES – a) Foundation masonry, base of foundation.
b) Gravity Dam and Retaining Wall c) Below Flooring.
d) Leveling work over PLINTH.

 RCC - ({Cement + Sand+ CA +Water} this mixture is Reinforced in STEEL)
 Strong in compression and tension
 Hard, Durable and bear all types of stresses.
 R/f may be MILD STEEL Or TOR STEEL BAR.
 Minimum Grade used is M20.
 Manufactured on site may be Hand mixing or Machine Mixing.
USES
– a) Construction of multi storied buildings.
b) Road pavement.
c) Water tanks, bridges, concrete pipes.
d) Concreting of beams, columns, slabs, footing etc.

Sand
Aggregate

 Advantages of R.C.C.
 a) Highly durable, Fire-resisting.
 b) Monolithic character provides rigidity to structure.
 c) Fluidity of concrete and flexibility of Reinforcement make it possible to mould into various shapes.
 d) Cost of maintenance is negligible.

 Casted in Separate form and then placed.
 Casted in casting yard or on building site.
 After casting, transported and placed in position by cranes.
 PC units are –
1) Hollow concrete blocks
2) Tiles
3) Pipes
4) Roof Slabs
5) Electric Poles
6) Stair Case
7) Rail Sleepers

 Casting structural Elements like BEAMS,
COLUMS, SLABS, WATER TANKS, GIRDERS,
FRAMES, TRUSSES, SEPTIC TANKS,
WATERSUPPLY AND DRAINAGE PIPE, FENCING
POST, ELECTRIC POLES, CAISSIONS, TRAFFIC
BARRIERS, ROAD DIVIDERS, CONRETE PILES,
BRIDGE PIERS ETC………
 Manufacturing-
(Reinforcement – Mould – Concreting )
 Advantages-
 Mould can be reused when production is in bulk
 Better quality control as production is in factory
 Smooth surface may be achieved and plastering may be avoided.

 Def:Concrete in which reinforcing steel bars/tendons are stretched and anchored to compress it and thus increase its resistance to stress.
Methods –
A) Pre-tensioning
B) Post-tensioning

 Steel reinforcement is first tensioned with hydraulic jack and then concreting is done and harden for 28 days.
 Used for LONG SPANs.
 Higher tensile strength is obtained.

 Steel reinforcement is enclosed in ducts or metal sheets, concreting is done and harden for 28 days, then these steel reinforcements are tensioned with the help of hydraulic jack and anchored.
 Used for LONG SPANs
 Higher tensile strength is obtained.

 PSC girders in bridges.
 Railway Sleepers
 Electric pole
 Beams of large span
 Pile foundation
 Slabs
•Pile for foundation
 Size of structural member is reduced
 Members can resist shocks, vibration, impact
 Mostly high quality material is used.

 STRUCTURE OF BUILDING IS DIVIDED IN
Two CATEGORIES-
1) Superstructure – (above GS)
2) Substructure – (Below GL)
Components of Substructure: a) Foundation b) Plinth c) Damp proof Course (DPC)

 Total Load of SUPERSTRUCTURE is transmitted to the FOUNDATION BED via SUBSTRUCTURE.
 Def .:- ‘Structure which supports the superstructure’
 Transmitting media – usually made up of RCC
 Foundation Bed – made up of hard (Nat/Art) bedrock or soil.
FUNCTION OF FOUNDATION
 Transfer and Distribute the load uniformly.
 Prevent from Uneven settlement
 To maintain stability of structure from overturning and sliding
 Forms a level for laying the masonry courses.

 Structure will be safe if the bearing capacity of the soil is satisfactory.
 Bearing capacity = Maximum Load carrying capacity
 ULTIMATE BEARING CAPACITY-
Max. avg intensity of applied pressure that the underlying area can carry before its shear failure of material.
 Safe Bearing Capacity = Ultimate BC
-----------------------
FOS

1.5 to 2 – Temporary structures
2 to 3 - Shallow Footing
2 to 6 - Pile Foundation
5 to 10 – Rock Structures
2.5 - Buildings FOUNDATION
Value of FOS (difference in loads, ground strata, position of Ground water)

 It is the vertical downward movement of the foundation.
 Amt. of settlement may be different for different types of soil
 Settlement is a time dependent process
Clayey Soil – Very Gradual (Long time and more)
Sandy Soil – Quick and less.
TYPES OF SETTELMENT
 Uniform Settlement
 Differential Settlement

•Uniform
Settlement
•Sliding /
Overturning
•Differential
Settlement

 Vertical DOWNWARD movement of the total base of structure is EQUAL.
 US causes when
Uniformly distributed load.
Uniform soil / rock beneath
 NO Damage to structure.
 Excessive US may damage -
Water supply & Drainage lines
Telephone & Electric Cables.

 Vertical DOWNWARD movement of the total base of structure is Non - Uniform.
 DS causes when
Distributed load on the structure is uneven
Different soil / rock beneath the foundation.
 DS is a DANGEROUS Settlement.

•P
P
•P
•P
•P
•P1
•P2
•P3

Strip Footing
Shallow
Foundation
Deep Foundation
Spread Footing
Combined Footing
Strap/ Cantilever
Footing
Mat or Raft
Footing
Isolated Footing
Pile Foundation
End Bearing Pile
Friction Pile
Simple
Stepped
Square
Rectangular
Circular
Stepped




– Used to distribute
Concentrated Load from Superstructure over a wider area. (WALL FOOTING)

•Step
•Offset
1) Simple Strip Footing
2) Stepped Strip Footing
Used below light structure.
Garden wall or Compound Wall.
Temporary structures.
•Stepped Wall Footing
•Simple Wall Footing

ISOLATED / PAD FOOTING (Column Footing)
 These are used to support Individual Column.
 They may be in different shapes
Rectangular
Square
Circular
Sloped
 Used for modern RCC building.

 When loads on adjacent columns are very high or
BC of the soil is less, two columns are grouped together to form a combined footing
 Differential settlement is reduced as the base is common.
 Case 1: Same Loading on 2 column (W1 & W1) – Rectangular Footing
 Case 2: Diff Loading on 2 column (W1 & W2) – Trapezoidal Footing

W1
W1

 Provided in following conditions:
Case I – If it is not possible to provide footing exactly below the column.
(boundary restriction)
Case II – Distance between the 2 columns is so large that combined footing is not possible.
 In such cases a cantilever beam connects these 2 columns.

Deep Foundation
D/B >1
PILE
Function Based
End Bearing Pile
Material Based
Friction Pile

 A sender Column capable of transferring the structural load to the deep underlying layer.
 End of column is usually sharp.
 At the G.L the pile is covered with PILE CAP, on which COLUMN is constructed.

 Load is transferred to Hard Strata, through soft soil strata, at a greater depth.
 Pile rests on HARD STRATA at greater depth.

 Load transfer is by SKIN FRICTION without any end bearing.
 Soil offers resistance to pile by virtue of
FRICTION.

 TYPES OF LOADS-
• DL & LL
• Wind Load
 EARTHQUAKE CONSIDERATIONS
 TYPES OF CONSTRUCTION
• Load bearing
• Framed
• Composite
 MASONRY
• Stone masonry
• Brick Masonry

 PART OF STRUCTURE ABOVE Plinth Level (G.S)
Components- (Wall, Roof, Door, Windows, Flooring,
Slab etc……)
 Plinth – Part of Structure lying above
Substructure and below Superstructure.
 Loads acting on Superstructure – DL, LL, Wind Load,
H.W
 Q1. Write comparison of Superstructure and Substructure

1) Dead Load (D. L)
2) Wind Load (W. L)
3) Live Load (L. L)
4) Earthquake Load (Eq. L)
 These loads may act simultaneously (W.L, Eq. L may vary)

 Load of Material – Self wt. of Bldg. Components.
 D.L = (Volume x Unit Weight of material) (KN/m 3 )
MATERIAL
PCC
RCC
Brick
Steel
Brick Masonry
Stone Masonry
UNIT WEIGHT (KN/m 3 )
24
25
22
78
18
22

 Movable Superimpose load acting on structure.
(Occupant, Furniture, Equipment, machinery, etc……)
 It is usually consider acting uniformly .
 In case of Multistoried building, FULL LOAD on each floor is not considered for calculating
Foundation Load.
 Minimum L.L. depends on type of Building.
TYPE (Purpose)
Residential, Hospital
Office Room, Small Work Place
Bank, Reading Hall
Class Room, Restaurants
Min L.L.((KN/m²)
2.00
2.45
3.00
4.00

 W.L is effective in ‘HIGH RISE BUILDING’.
 Wind Pr. {P = kV²}
P = wind pressure in (KN/m²) k = Coefficient depending on wind velocity, size, shape of structure and Atm. Temperature.
 Ht. < 3 times the width (W.L may be neglected)



 Methods of constructing SUPERSTRUCTURE.
1) LOAD BEARING STRUCTURE
2) FRAMED STRUCTURE
3) COMPOSITE STRUCTURE
 Choice for the method of construction depends on –
- Number of Floors,
- Area Covered,
- Type of Structure,
- Bearing Capacity of Land,
- Economy

LOAD BEARING CONSTRUCTION
 Load transferred to wall as roof and floors are connected to the wall
 Roof & Floor – Wall – Wall Footing – Underlying Strata
 Economical up to 2 storeys (as no of storeys increases wall thickness increases & carpet area reduces)
 Feasible where HARD STRATA is available at
Shallow depth.
 Now a days – Temporary and important structure are build.
 E.g. - Shaniwarwada, C.O.E. Pune, Central Bldg.

 Slab – Beam – Column – Footing – Underlying Soil.
 Used for MULTISTORIED BUILDING.
 Frame is constructed by RCC
 Speed is faster compared to LBS
 If HARD STRATA NOT available at considerable depth, PILE foundation or RAFT foundation is designed.

 COMBINATION of L.B.S & F.S
OUTER WALL – L.B.S.
Columns and Beams are provided intermediately.
 Floors and Roofs are supported by walls and frames.
 Used for Industrial Sheds, Warehouses where spans are long.