Performance of eco-friendly masonry units made with limestone calcined clay cement (LC3)

This paper aims to evaluate the performance of masonry units manufactured in a plant for the first-time using limestone calcined clay cement (LC3). Locally available raw materials in Iraq were employed to produce the masonry blocks by using an automated block maker in a local plant. In addition to the control ordinary Portland cement (OPC) blocks, two types of LC3 masonry blocks were produced to evaluate their performance. These two types were LC3 blocks made by replacing 25% and 50% of OPC with calcined clay and limestone, namely, LC3-75 and LC3-50 blocks, respectively. Following the production, the performance of the blocks was assessed through compressive strength, absorption, and density tests. The results showed that the values of compressive strength for LC3-75 and LC3-50 blocks, at 28 days, were 94% and 82% of OPC blocks, respectively. According to the American Society for Testing and Materials, the compressive strength of LC3-75 blocks satisfied the requirements of loadbearing units, whereas that of LC3-50 blocks fulfilled the requirements of non-loadbearing units, in terms of compressive strength and absorption. Compared with OPC blocks, the estimated reductions in embodied carbon by utilizing LC3-75 and LC3-50 blocks were 18% and 36%, while the reductions in mass were 0.9% and 1.7%, respectively.