Durability studies on fly-ash based laterized concrete: A cleaner production perspective to supplement laterite scraps and manufactured sand as fine aggregates

Abstract

This research aims to produce sustainable concrete by effectively utilizing laterite scraps as fine aggregates in fly ash-based cement concrete and assessing its durability characteristics. This utilization reduces sand extraction, pollution to the environment, and conserves natural reserves by reducing the need for virgin materials. To evaluate the engineering properties, durability properties and sustainable property of laterized concrete, a control mix made with 0% laterite scraps and four mixes made with 25%–100% laterite scraps at 25% intervals with the same high-quality cement, fly ash, and coarse aggregate was used. Due to the influence of clay minerals such as kaolinite and montmorillonite in laterite scraps, the slump values ranged from 85 to 15 mm, with the control mix being more workable than the laterized samples. The combination of 75% manufactured sand and 25% laterite scraps in concrete were found to remarkably enhance the residual compressive strength. A significant increase of compressive strength of about 11% was achieved at replacing 25% laterite scraps at 28 days. Higher replacements of 50%, 75%, and 100% laterite scraps decrease cubes strength by approximately 3%, 15%, and 28%, respectively. From the compressive strength test results, it is quite evident that utilizing laterite wastes reduces the amount of virgin aggregates needed to produce concrete resulting in less natural resource consumption. Moreover, the test results of durability parameters such as water absorption, permeability, sorptivity, drying shrinkage, and rapid chloride penetration of laterized concrete mixes containing 50% replacement recline within the acceptable limits as per standards, confirm their intended performance throughout the specific structural service life. The embodied energy assessment of laterized concrete mixes achieved the most significant reduction of 22.41 MJ/m3, revealing the advantageous role of laterite scraps in reducing energy expenditure.