Effect of slag sand as river sand and its influence on compressive strength of the cement mortar

Abstract

Cement mortar is widely used in all construction activities due to its strong binding and durable properties. Sand is the main ingredient in preparing cement mortar in different ratios from 1:1 to 1: 8 for various elements in construction. As we are facing a shortfall for river sand, an alternate crushed stone as M−sand is used everywhere for river sand. Mining, crushing rock particles, and stone quarrying also have long-term effects on the environment. Industrial effluents from the manufacturing of steel, copper, and coal also possess some aggregates properties, dumping them as waste, leading to disposal challenges & adverse environmental impacts. Hence researchers are trying different ways to minimize waste disposal and address the scarcity of river sand in construction activities. One such trial is attempted in this study to utilize the waste effluent slag sand obtained from the steel industry as a replacement for sand. The experimental investigation is conducted by replacing slag sand in various percentages from 0 to 100% in the ratio of 1:3 cement mortar. A microstructure test was performed on slag sand to check its feasibility compared to M−sand, and the compressive strength of mortar was analyzed at 3, 7, and 28 days of curing. Also, an Ultrasonic pulse velocity test is performed to evaluate the quality of the mortar. Test results revealed that slag sand increases strength with age. But slag sand absorbs more water compared to M−sand, making the mix stiffer. Adding the extra water corresponds to water absorption percentage, and strength increased further at all ages of curing and improved cement mortar quality. Thus, the optimum percentage of slag sand as a replacement for M−sand is 50% in cement mortar. Thereby helping minimize the disposal challenge by producing eco-friendly mortar and reducing the construction cost. This slag sand proves as a sustainable material for futuristic constructions.