LOW HEAT CEMENT – COMPOSITION, PROPERTIES AND USES

Low Heat Cement

Low Heat Cement is a special tailored cement which generates low heat of hydration during setting.This cement is less reactive than Ordinary Portland Cement because it is obtained by increasing the proportion of C2S and reducing the proportion of C3S and C3A.This reduction in the content of more rapidly hydrating compounds C3S and C3A results in a slow development of strength but the ultimate strength is the same as that of ordinary Portland cement.As per Indian Standard Specification the heat of hydration of low heat cement shall be:     

7  Days – Not more than 65 calories per gram.     

28 Days – Not more than 75 calories per gram. 

Composition of Low Heat Cement

Low Heat Cement contains 5% of Tricalcium aluminate (C3A) and 46% of Dicalcium Silicate (C2S).

Properties of Low Heat Cement

ITEM	STANDARD VALUE
Specific Surface Area	250  m2/kg Min
Initial Setting	60  Min
Final Setting	12  hours Max
Compressive Strength at 7 Day	13   Mpa Min
Compressive Strength at 28 Day	42.5Mpa Min
Breaking Strength at 7 Day	3.5  Mpa Min
Breaking Strength at 28 Day	6.5  Mpa Min
Heat of Hydration at 3 Day	230 KJ/kg Max
Heat of Hydration at 7 Day	260 KJ/kg Max

Characteristics of Low Heat Cement

• Excellent impact erosion.
• Excellent wear resistance.
• Excellent resistance to rapture.
• Excellent resistance to drying shrinkage.
• Low heat of hydration is 20% lesser than OPC.
• The amount of water required for hydration is low.
• Initial strength is low but high grouth rate of final strength.
• High workability is obtained as the concrete is fluidly in nature.

Uses of Low Heat Cement

• Mainly used in constructing dams,large footings,large raft slabs,wind turbine plinths.
• To make workroom surface of factories such as chemical plants and sulphuric acid factories.

Advantage of Low Heat Cement

• It is used in hot weather condition.
• Good resistant to sulphate attack.
• Improvised durability performance.
• Assists in minimising the potential for thermal cracking in thick concrete sections.

Disadvantage of Low Heat Cement

• It will also need more curing time.
• Cost of the cement is higher than that of ordinary cement.
• This cement cannot be used in the cold weather conditions.
• Initial strength gained is lower than that of OPC concrete,but the final strength is same as that of OPC.