Compressive Strength Investigations of Foamed Mortar Incorporating Sandblasting Waste As Supplementary Cementitious Materials

Silica sand is one of the abrasive materials commonly used in the sandblasting process. The production of sandblasting waste is raising yearly, linear with the rapid development of the shipping industries. Silica sand was produced as by-product waste, approximately 400 ton per year. This research focused on compressive strength investigations of the foamed mortar incorporating silica sand as a supplementary cementitious material (SCM). Foamed mortar is a lightweight mortar made from a mixture of water, cement, sand, and foam, which can reduce the density of the mortar for construction purposes. Prior to use as SCM, the silica sand was pre-treated by using mechanical grinding to produce finer materials similar to cement. The observations were applied to pre-treated silica sand, such as chemical compositions, particle size analysis, normal consistency test, and setting time test. The specimens used in this research were mortar concrete with dimensions 5 x 5 x 5 cm and tested according to ASTM C579-01. The pre-treated silica sand varied from 10%, 20%, and 30% by weight of cement, were applied in this investigation. The compressive strength and spesific gravity were also observed. The results show that 20% cement replacement with pre-treated silica sand is the optimum composition and has 52.2 MPa in compressive strength at 28th days. These investigations conclude that pre-treated silica sand is potentially used as SCM in foamed mortars for sustainable concrete materials.