Improving the performance of crushed limestone concrete utilizing supplementary cementitious materials: A case study in Iraq

Abstract

This paper presents an experimental work conducted to study the properties of concrete incorporating (0-100) % of local (in Iraq) crushed limestone (CLS) as a partial replacement of coarse aggregate. Supplementary Cementitious Materials (SCM) such as High Reactivity Metacaoline (HRM) and Rice Husk Ash (RHA) were added to the mixtures to improve the properties of fresh and hardened concrete. The selective mixtures in this study were arranged into three groups, the first without (SCM), the second with (RHA), and the third with (HRM). Each of them (being with different ratios of (CLS) as a coarse aggregate) was tested for comparison with the reference mixtures. The slump and air contents were evaluated for the fresh concrete. The absorption as well as compressive strength (CS) and flexural strength (FS) were evaluated for the hardened specimens after 7 and 28 days. According to the results, the concrete with CLS as a coarse aggregate gained less performance than the ordinary concrete but the (SCM) improved the properties of the concrete mixtures. The results show that the HRM was more effective than the RHA with respect to the mechanical properties.