Usage of supplementary cementitious materials: advantages and limitations

Barbara Pacewska,Iwona Wilińska

doi:10.1007/s10973-020-09907-1

Abstract

It is well known that cement production is not neutral for natural environment among others due to high CO2 emission. Different strategies of mitigation of negative environmental impact of its production are developed. One of the ways is utilization of supplementary cementitious materials (SCMs) in the manufacture of cement and concrete. Introduction of aluminosilicate SCMs into binding mixture makes that more amount of so-called C–A–S–H phase appears in hydration products, affecting microstructure and properties of final hardened composite. The aim of this work is to discuss the possibilities of utilization of selected SCMs in different binding mixtures including some advantages and limitations. Literature review on the subject was carried out. Some of our own research results were also presented. In the Part I of this review, some information about history of ancient binding materials and the possibilities of inspiring modern engineers with ancient constructions in the aspect of using SCMs in modern concrete were presented. Using pozzolanic aluminosilicate SCMs in relation to their influence on formed products, microstructure and mechanical properties of hardened material were discussed. Some problems with possibilities of study of SCMs reaction degree were identified. Emphasis was put on the usefulness of isothermal calorimetry and thermal analysis for investigations of hydration process and identification of hydrated products as well as evaluation of degree of reaction of SCMs.

Highlights

Cement and cement concrete are common construction materials manufactured in large amounts
Emphasis was put on the usefulness of isothermal calorimetry and thermal analysis for such investigations, especially in the case of evaluation of degree of reaction of supplementary cementitious materials (SCMs)
As it has already been mentioned above (Fig. 1), such kind of SCMs, i.e. containing low calcium components and not showing self-cementing properties but being able to react with Ca(OH)2 in the presence of water, are commonly known as pozzolana

Summary

Introduction

Cement and cement concrete are common construction materials manufactured in large amounts. Additional amount of C–S–H1 and C–A–S–H phases are formed while Ca(OH) content is reduced As it has already been mentioned above (Fig. 1), such kind of SCMs, i.e. containing low calcium components and not showing self-cementing properties but being able to react with Ca(OH) in the presence of water, are commonly known as pozzolana (pozzolanic materials/additives). Reactivity of SCMs is often lower than reactivity of clinker phases [22], which causes that for high and very high cement replacement level, pozzolanic reaction and acceleration of cement hydration may be insufficient to obtain required properties of final composite In such case different ways of activation of the system and increasing of SCM reactivity are considered [29]. Additional effect of heat release which can be observed for some samples at the falling curve in the 4 th

50 CEM II

Conclusions

Findings

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