Developing a geopolymer pastes using marble dust

ABSTRACT This paper investigates the use of marble dust waste, fly ash, and silica fume as raw materials for manufacturing geopolymer pastes. The chemical composition of each raw material is established using chemical analysis (X-ray fluorescence XRF) and mineralogical analysis, X-ray diffraction (XRD) pattern of raw materials. The experimental work was divided into three groups (A, B, C) according to the water to binder ratio (w/b) (A =28%, B = 30%, C = 33%). Each group is further divided into five subgroups according to the percentage of marble dust, fly ash, and silica fume. The samples are cured at 60°C for three days. The properties of the geopolymer pastes are determined by performing the following tests: compressive, tensile, and flexural strength and water absorption. The highest mechanical properties were obtained from mixes containing 70% fly ash and 30% marble dust at w/b = 0.28. It was 40% more than those obtained from control mixes containing 50% fly ash and 50% marble dust. It is worth mentioning that the best amount of marble dust was 30% as the resistance of the geopolymer paste reached values up to 237.8 kg/cm2. The results were confirmed by SEM imaging.