An experimental investigation of the effect of replacing light grains of pumice and scoria with natural sand on the properties of cement-slag mortars

Authors

1 Department of Civil Engineering, Qeshm Branch, Islamic Azad University, Qeshm, Iran

2 Professor, Department of Civil Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz, Iran

3 Professor, Department of Civil Engineering and Environmental, Amirkabir University of Technology, Tehran, Iran

10.22034/ceej.2024.60710.2340

Abstract

11 mixing designs including one reference design and ten cement-slag mortar designs were made. The ratio of water to cement in all designs was 0.40. In the mentioned ten projects, slag powder from Ahvaz steel plant was used instead of 30% cement.scoria was used, and in five other designs, pumice was used. In the experiments, cubic and prismatic speceimens with dimentions 50 and 40x40x160 mm were used, respectively. The speceimens were all processed in two environments including Ahvaz drinking water and laboratory temperature. In all ten mixing plans, scoria and pumice aggregates were replaced by 30%, 40%, 50%, 60% and 70% with natural sand. To determine the rheological, mechanical and durability properties of the flow test, compressive and bending strength tests, electrical resistance, volumetric water absorption, water penetration depth tests and scanning electron microscopy (SEM) were performed. 50% and 30% pumice instead of sand are optimal for speceimens cured in drinking water at laboratory temperature. The use of scoria at the rate of 30% and 40% instead of sand is also optimal for the speceimens cured in drinking water at the temperature of the laboratory environment. It was concluded that the speceimens cured in the laboratory environment temperature of the optimum design of 40% scoria and the speceimens cured in the drinking water environment of the optimal design of 50% pumice at the age of 91 days are 14% and 5%, respectively, compared to the speceimens of the reference design. The drinking water environment had an increase in compressive strength.

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