Ground Granulated Blast Furnace Slag (GGBS): Effect of Particle Size and Dosage on Compressive Strength with Microstructural Analysis of Concrete

Abstract

In the present investigation Ground Granulated Blast Furnace Slag (GGBS) is used as replacement to cement by weight. The GGBS is used as partial replacement for cement in the concrete mix with particles in the range of 125-250µm, 90-125µm, 45-90µm, 20-45µm and <20µm. The dosage of GGBS is varied from 10% to 40% at an increment of 10% to evaluate the compressive strength of concrete along with microstructural analysis of concrete. The microstructural study is carried out using scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS).The two main compounds observed in the study are Silica and Calcium, their consumptions before and after the pozzolonic reactions. The optimum compressive strength is observed for <20 µm size particles at 20% replacement level and it is also observed that the consumption of calcium is more for the above said replacement.