Adding limestone fines, fly ash and silica fume to reduce heat generation of concrete

Abstract

The conventional method of adding limestone fines and fly ash as cement replacement to reduce the heat generation of curing concrete would significantly lower the strength. To reduce the heat generation and at the same time maintain a reasonable strength, adding limestone fines as cementitious paste replacement (the cementitious paste is the paste formed of cementitious materials and water) and adding fly ash together with silica fume as cement replacement should be a better method. Herein, a series of concrete mixes with water/cementitious materials ratios ranging from 0·40 to 0·50, and various limestone fines, fly ash and silica fume contents were tested for their workability, strength and heat generation. The results revealed that limestone fines, fly ash and silica fume are all effective in reducing heat generation. With all of them added, a concrete mix with a workability of at least 200 mm slump, a cube compressive strength higher than 65 MPa and an adiabatic temperature rise of only 30°C is developed.