Question

What is the consequence of SCM on the heat of hydration?

Answer 1

SCM refers to supplementary cementitious materials such as Fly Ash, Blast Furnace Slag, Silica Fume, Quartz Powder etc.These materials are often added to concrete to make concrete mixtures more economical, reduce permeability, increase strength or influence other concrete properties. It also improve the workability of Fresh concrete and enhance the durability of hardened concrete SCM reduces the embodied energy and CO2 emissions from the concrete. Concrete setting time may be retarded with some SCM used at higher percentage. This can be beneficial in hot weather.The properties of SCMs concrete are described through a pozzolanic reaction between a pozzolana and calcium hydroxide. The Pozzolanic reaction generates less heat than ordinary portland cement because the reaction is similar to a C2S reaction.

SiO2/ Al2O3 + Ca(OH)2 → C-S-H gel

Most important consideration in the use of SCM, is sustainability dimension of concrete, as with increased use of SCM, we are expecting to reduce substantial volume of CO₂ emissions, thereby mitigating the environmental impact of concrete production.