Early Strength of Concrete by using Ground Granulated Blast Furnace Slag and Local Ordinary Portland Cement Materials

Abstract

It is well known that using Ground Granulated Blast Furnace Slag (GGBFS) to replace some of the cement in concrete will cause it to take longer to reach its ideal compressive strength. However, several precast concrete manufacturing processes require high initial compressive strength values to speed up production. The impact of partially substituting GGBFS for cement on the initial strength values of concrete is investigated in this work. The 300 concrete cylinder samples were used to accomplish the study's goals. Compressive and split tensile tests determined the concrete's initial compressive strength and split tensile strength outputs. Therefore, the ideal percentage of GGBFS can replace cement by 20–30% to achieve the desired early compressive strength of 16 MPa in 16 hours by setting the proper water-cement (w/c) ratio at about 0.25. Because a low w/c ratio leads to low workability, some additives, such as silica fume or superplasticizer, can be employed to further increase the workability and performance of concrete.