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Asphalt. Cement. Construction Materials. Woods. Concretes. Sand. 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
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Asphalt Cement Construction Materials Woods Concretes
Sand • 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 • Natural Sand – obtained from pits, shores, riverbeds seabed's… • Artificial Sand – obtained from crushing of stones.
Sand Types of Sand (depending on fineness) • Coarse Sand – retaining on sieve 4.75 mm • Fine Sand – passing through sieve 4.75 mm Uses • PCC, RCC, PSC • Cement mortar, Lime Mortar • Coarse Sand - plaster on Ex. Wall, Fine Sand – Plastering on Internal Wall • Below flooring material • In filtration plant.
Classification of Rocks Geological – Igneous Rock, Sedimentary & Metamorphic Physical – Stratified, un-stratified and Laminated. Chemical – Siliceous, argillaceous, calcareous Hardness of Stone - Very hard, hard, medium, soft STONECheapest, Durable and obtained from ROCKProperly dressed and shaped before it is used.
Uses of Stone • Marble • Slate
Granite Material • Polished Surface • Rough Texture
Uses of Stone • 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 • 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
STEEL • Cast iron is iron or a ferrousalloy which has been heated until it liquefies, and is then poured into a mould to solidify. • Wrought iron is an ironalloy 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.
Classification of STEEL • 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
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….
CONCRETE (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
Concrete Types • (PCC) Plain Cement Concrete • (RCC) Reinforced Cement Concrete • (PC) Precast Concrete • (PSC) Prestress Concrete
Types of Concrete • PCC – (cement + FA+ CA +Water) Strong in compression and weak in tension Hard and Durable Manufacturing – Hand mixing or Machine Mixing. USES – • Foundation masonry, base of foundation. • Gravity Dam and Retaining Wall • Below Flooring. • Leveling work over PLINTH.
Types of Concrete • 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.
R.C.C. Cement Sand Aggregate Water Steel
Concrete • 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.
PRECAST CONCRETE (P.C.) • 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 – • Hollow concrete blocks • Tiles • Pipes • Roof Slabs • Electric Poles • Stair Case • Rail Sleepers
Uses Of P.C • 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.
PreStress Concrete. • Def:- Concrete in which reinforcing steel bars/tendons are stretched and anchored to compress it and thus increase its resistance to stress.Methods – • Pre-tensioning • Post-tensioning
Pre-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.
Post-tensioning • 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.
Uses of PSC • PSC girders in bridges. • Railway Sleepers • Electric pole • Beams of large span • Pile foundation • Slabs Advantages • Size of structural member is reduced • Members can resist shocks, vibration, impact • Mostly high quality material is used. • Pile for foundation
STRUCTURAL COMPONENTS • 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)
Foundation • 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.
BEARING CAPACITY • 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
FOS1.5 to 2 – Temporary structures2 to 3 - Shallow Footing2 to 6 - Pile Foundation5 to 10 – Rock Structures2.5 - Buildings FOUNDATIONValue of FOS (difference in loads, ground strata, position of Ground water)
SETTLEMENT OF FOUNDATION • 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
Type of settlement • Uniform Settlement • Sliding / Overturning • Differential Settlement
UNIFORM SETTELMENT • 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.
DIFFRENTIAL SETTLEMENT • 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 • P2 • P1 • P3
SHALLOW FOUNDATION • Spread Footing – Used to distribute Concentrated Load from Superstructure over a wider area. (WALL FOOTING)
STRIP FOOTING • Simple Strip Footing • Stepped Strip Footing Used below light structure. Garden wall or Compound Wall. Temporary structures. • Step • Offset • Simple Wall Footing • Stepped 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.
COMBINED FOOTING • 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
STRAP / CANTILEVER FOOTING • 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.