Studies on reactivity of limestone-calcined clay cement for sustainable infrastructures

Abstract

In the present scenario, urbanisation is accelerating at an exponential rate all around the world and approximately 70% population is expected to be living in urban areas by 2030. This rapid urbanization has created a challenge before construction sector to develop sustainable and durable building materials with minimal emission of Green House Gases (CO2) during their production without compromising their performance. In this regard, reducing the cement clinker content might have positive effects on the environmental aspects of concrete, where Limestone calcined clay cement (LC3) is found to be more promising than other blended cements. In the present study, different combinations of clays and limestones were used to prepare blends. The existing testing techniques for the pozzoloan potential are still same. This raise a question of applicability of existing techniques of reactivity potentials of supplementary cementitious materials (SCMs) over their blends. This study will look for the similarity in phase formed during the hydration of blends in Ordinary Portland cement (OPC) as well as Calcium hydroxide (CH) system. Similar products formation can conform the applicability of exiting testing techniques to their blends also. Therefore, the blends of calcined clay and limestone were mixed with pure CH and OPC system to monitor their reactivity. For characterizing the reactivity of blends X-ray diffraction technique was used. The reactivity of blends in two different system (CH and OPC) are being compared to observe the potential of clay-limestone blends in cement as well. From the study it has been found that the product form are same in CH and OPC system, which allows exiting technique applicability on blends of SCMs.