Mechanical and Durability Properties of Concrete Incorporating LD Slag

Abstract

Concrete usage in recent decades has skyrocketed, which has led to immense pressure on the natural resources such as river sand and coarse aggregates involved in its production. This continuous consumption of natural resources is due to increased industrialization and urbanization. The circular economy concept, i.e., usage and recycling of waste products, can be incorporated into concrete production to alleviate the overutilization of natural resources. Overutilization of natural resources has impeded the movement towards green concrete in construction, i.e., utilizing waste materials in its production, steel slag waste being one of them. Linz-Donawitz slag (LD Slag) is one of the steel slag generated during the Basic Oxygen Furnace (BOF) steel-making process. Accumulation of LD slag has become cumbersome in India, posing a problem of landfills, aggravating limited land availability and environmental degradation, i.e., abating soil and water quality due to the leaching of toxic and heavy metals. Previous studies employed LD Slag as an alternative to natural aggregates in concrete production. Moreover, fewer experimental studies have examined whether weathered fine LD Slag can substitute for fine aggregates in concrete. However, none of the studies has focused on the comparative behavior of weathered coarse LD slag and fine LD slag incorporated in Normal Strength Concrete (NSC) and metakaolin-based High-strength Concrete (HSC). The present experimental study focuses on determining the ideal replacement level of coarse and fine aggregates with LD Slag, one at a time. Natural aggregates were replaced volumetrically, one at a time, with LD Slag at 25, 50, 75 and 100%. Physico-mechanical and durability properties such as hardened concrete density, ultrasonic pulse velocity, compressive strength, split tensile strength, flexural strength, modulus of elasticity, drying shrinkage, water absorption, sorptivity and abrasion resistance were evaluated. Furthermore, different data sets, one for mixes incorporating LD slag