Mechanical and durability performance of cementitious matrices with low cement and different additions

Abstract

Nowadays, the decarbonization of the concrete sector is a priority to counteract the global environmental harmful. Knowing that Portland cement is responsible for significant anthropogenic emissions worldwide, the optimization of cement dosage on concrete mixtures is a key issue, combined with the mechanical and durability performances, allowing to improve its eco-efficiency. The goal of the present work consists in optimizing the formulation of concrete matrices, used to produce reinforced concrete poles for the electric lines, by increasing the packing density, reducing the cement dosage and incorporating different additions, in order to promote the performance. Two different formulations of matrices were considered, fresh moulded concrete with dry consistency and formwork moulded concrete with plastic consistency. For each one, different dosages of cement and various additions (limestone filler, fly ash, natural pozzolan, electric furnace slag) were considered to replace the cement, which were used single or combined. The mortar matrices of the concrete formulation were characterised regarding: fresh properties; mechanical properties (flexural and compressive strengths and Young’s modulus); shrinkage and durability properties (capillary water absorption, carbonation and chloride ingression resistances). The influence of the additions on those properties was analysed and compared with reference cement-based mixtures and the main conclusions are presented.