C OMPOSITION OF C ONCRETE By: o Rushi Patel-D14CL04 o Naresh Prajapati-D14CL01

U SES OF P ORTLAND C EMENT C ONCRETE : Buildings Bridges Pavements Concrete block buildings

O THER U SES OF C EMENTITIOUS M ATERIALS : Mortar for masonry Grout (protection, leveling, bonding,...) Shotcrete Cement board Soil Stabilization Railroad ties, countertops, moldings...

P ORTLAND C EMENT H ISTORY Egyptian Pyramid of Cheops (3000 B.C.) First Calcareous Cement (CaO based) Calcined gypsum Roman and Greek Projects First Hydraulic Cements (100 B.C.) calcined limestone and clay

H ISTORY OF C EMENT : 2000 B.C.: Egyptians used cement in mortar when making Pyramids 27 B.C.: Roman cement made of lime and volcanic ash 1756: Smeaton rebuilt Eddystone Lighthouse 1824: Joseph Aspdin discovered and patented “Portland” cement

Isle of Portland Quarry Stone next to a Cylinder of Modern Concrete

C EMENT IS A M ANUFACTURED M ATERIAL :

C OMMON S OURCES FOR R AW M ATERIALS : Lime (CaO) - Limestone, shale Silica (SiO 2 ) -Clay, sand, shale Alumina (Al 2 O 3 ) - Clay, fly ash, shale Iron (Fe 2 O 3 ) - Clay, iron ore

P ORTLAND C EMENT P RODUCTION : 5/8 CaOLimestone or calcareous rock 1/5 SiO 2 Clay or argillaceous rock 1/10 Al 2 O 3 Clay or Ore 1/20 Fe 2 O 3 Clay or Ore 1/20CaSO 4 *2H 2 O Gypsum

C EMENT C LINKER :

C LINKER : ARTIFICIAL MINERAL CONTAINING : o C 3 Stricalcium silicate o C 2 Sdicalcium silicate o C 3 Atricalcium aluminate o C 4 AFtetracalcium aluminoferrite

P ORTLAND C EMENT P ROPERTIES : Hydraulic Fineness 90% finer than 45  m Setting Time Controlled False Set Flash Set

P ORTLAND C EMENT P ROPERTIES : Soundness MgO or Hard-Burned Lime Specific Gravity: 3.15 Heat of Hydration - Exothermic Reaction C 3 S & C 3 A LOI SO 3

H OW ARE P ORTLAND C EMENTS DIFFERENT ? Tricalcium Silicate (C 3 S) Dicalcium Silicate (C 2 S) Tricalcium Aluminate (C 3 A) Tetracalcium Aluminoferrite (C 4 AF) Four Main Compounds:

P OZZOLANS : Possess no cemetitious value until finely divided and mixed with water and cement Cherts, clays, shales Fly ash (by-product of coal) Silica fume (silicon manufacture)

Water:   Municipal  Well  Heated  Steam  Chilled  Ice  Recycled

Q UESTIONABLE W ATER : Water < 2000 ppm of total dissolved solids is satisfactory for making concrete. Water > 2000 ppm of dissolved solids should be tested for its effects on strength and time of set.

W ATER IN C ONCRETE : Increased water: reduced strength increased shrinkage and creep increases permeability reduced abrasion resistance reduced Freeze-Thaw resistance

I NFLUENCE OF A GGREGATES : STRENGTH Aggregate shape Aggregate size Aggregate texture

C ONCRETE M ATERIALS : Aggregate is the second most influential ingredient in concrete. Aggregate Occupies % of volume Fine Aggregate is typically % of total aggregate Mortar (Air, water, cement, fly ash, sand) is typically % of total volume of a mixture

A GGREGATES IN C ONCRETE : Fine: Sand or Crushed Stone (< 5mm) Coarse: Gravel or Crushed Stone (5-50 mm) Aggregate must be washed in many areas Granite & other crushed stone Recycled concrete All must satisfy ASTM C33

C HOOSING A GGREGATE S IZE : maximum nominal size of aggregate 1/5 smallest dimension 1/3 thickness of slab 3/4 clearance between rebars Congestion Shrinkage Mass Concrete

C OMPRESSIVE S TRENGTH : Strength f c ' (required 28 day compressive strength) f cr ' (actual average 28-day strength of mixture) f c (compressive strength of concrete) f cr ' is based on field records and laboratory results variations in materials variations in mixing times and methods variations in transportation time and methods variations in the preparation of test cylinders

S TRENGTH (7 DAY ): I > 19.3 MPa (2800 psi) II > 17.2 MPa (2500 psi) III > 24.1 MPa ( days)

C ONCLUSION : Concrete can be use in place were hard surface is needed. Concrete is hard Concrete have more compressive strength.

T HANK Y OU