Effect of Mixing Approaches on Carbonation of Concrete

Abstract

Concrete is a porous composite matrix of aggregates and cement used for the construction of durable structures. Durability of concrete structures is greatly affected by carbonation, which directly depends on the porosity of the concrete. A weak Interfacial Transition Zone (ITZ) between cement paste and aggregate particles leads to local porosity. As mixing approaches influence the microstructure of the ITZ, optimizing the mixing approach is an effective way to produce durable concrete by strengthening the ITZ. The present study prepares concrete test specimens using five different mixing approaches, apart from control specimens prepared using normal mixing approach (NMA). These specimens are subjected to accelerated carbonation in a carbonation chamber. The depths of carbonation in concrete cast with different mixing approaches, are compared against that in the control specimen obtained by NMA. The compressive strengths of carbonated and non-carbonated concrete, obtained from different mixing approaches, are also compared. Results from this work are used to suggest suitable mixing approaches for achieving durability in future construction practices. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.