Some Engineering Properties of Limestone Concrete

In order to reduce energy consumption and CO2 emission and increase production, cement manufacturers are blending or intergrinding mineral additives such as slag, natural pozzolans, sand, and limestone. The reduced cost of limestone is mainly due to energy savings by substitution of a portion of the calcined clinker with a small amount of limestone and to the presence of limestone deposits near cement kilns, and hence, reduced transportation costs. This paper reports on a preliminary study underway on the performance of limestone cement mortar and concrete. The effect of different levels of limestone cement replacement (0% to 35%) on physical and mechanical properties of cement mortar is reported, as well as the effect of fineness of both clinker and limestone. From the test results, it was found that it is possible to manufacture cement with limestone addition with comparable or superior performance to that of ordinary Portland cement, provided that proper limestone quality is selected with optimum content and the optimum levels of fineness of both limestone and clinker are used. However, further research is needed to determine long-term performance, especially in marine and hot environments.