Fluxural Strength

fcr = 0.7 √fck N/mm2

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Penetration Test for Bitumen IS 1203 1978

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Cement IS 269

cement is used to bind the materials in concrete  The manufacturing process includes Proportioning of raw materials like chalk or limestone,Grinding and burning at 1400-1450OC in rotatory kiln. Due to intense heat the material becomes like spherical balls called clinkers. Gypsum is then added in 3-4%. Cement is formed by grinding the clinkers to required fineness. Tricalcium Silicate (C3S) hardens rapidly and is largely responsible for initial set and early strength. In general, the early strength of portland cement concrete is higher with increased percentages of C3S. Dicalcium Silicate (C2S) hardens slowly and contributes largely to strength increases at ages beyond 7 days. Tricalcium Aluminate (C3A) liberates a large amount of heat during the first few days of hardening and, together with C3S and C2S may somewhat increase the early strength of the hardening cement (this effect being due to the considerable heat of hydration that this compound evolves). It does affect set time...
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