Strength and Durability of High-Strength Mortar Containing Supplementary Cementitious Materials

ABSTRACT The properties of high-strength mortar (HSM) incorporating supplementary cementitious materials (SCMs) and various levels of steel fiber (TF) were studied. The measured properties include fresh properties, compressive and flexural strength, durability, and microstructure. The selected SCMs are calcined kaolin clay, limestone (LS), and quartz (QS) powder. The test results showed that the combination of clay and TF would reduce the workability and air content of fresh HSM mixtures. TF addition can boost the mechanical performances of HSM blended with SCMs. Moreover, TF addition improved the compressive strength of QS-HSM to a greater extent than that of LS-HSM. In contrast, the combination of TF, clay, and LS is conducive to increasing the bending strength of LS-HSM compared with those of QS-specimens at all TF levels. The shrinkage of HSM under different curing humidity can be alleviated by an appropriate TF dosage. In addition, the durability of HSM incorporating clay, LS, and TF is superior to that of QS-HSM. This HSM is designed with high-volume SCMs (40 % cement replacement) and low TF content (0–0.8 % volume fraction), retaining the core durable characteristics of traditional HSM with reduced carbon emissions and production costs.