Developing marble slurry as supplementary cementitious material through calcination: Strength and microstructure study

Abstract

The production of cement concrete composites usually results in high emissions of CO2 which results in severe damage to environment. Therefore, investigations are required to study and report materials that can be used as environmentally friendly binders. The present study is aimed at investigating and improving the supplementary cementitious behavior of marble slurry by calcination. The compressive strength, microstructure and physio-mechanical properties were investigated. The compressive strength results indicated that as compared to raw marble slurry paste the specimens fabricated with calcined marble slurry presented improved compressive strength. It was observed that up to 10% incorporation of calcined marble slurry resulted in almost 7% increase in 28 days compressive strength. The microstructure observations revealed that use of calcined marble slurry results in lower porosity and average pore diameter. The use of 10% calcined marble slurry resulted in 7.5% reduction of porosity. Moreover, the data obtained from 29Si NMR spectra revealed that use of calcined marble slurry as cement replacement resulted in increased degree of hydration and chain length. Based on the results obtained up to 10% of calcined marble slurry can be used as supplementary cementitious material to develop environmentally friendly binary blended cement. In conclusion it can be stated that supplementary cementitious behavior of raw marble slurry can be enhanced by calcination.