A Comparative Study on The Properties of Course Aggregate Mostly Available in Bangladesh

Over the past decade, a significant number of infrastructure projects have been implemented across Bangladesh, resulting in a rapid increase in demand for construction materials. In the fiscal year 2017 to 2020 alone, approximately 12.7 million tons of aggregate were consumed by the construction industry, of which only 13% were sourced locally. The rest were imported, leading to variability in concrete performance due to differences in aggregate characteristics. This study investigates the influence of commonly used coarse aggregate types on concrete properties, with a focus on developing sustainable infrastructure. Six widely used coarse aggregate sources Balason, Shebok, Torsha, Dandruff Mine, Pakur Black Stone, and Kothin Shila were selected for analysis. Laboratory tests were conducted to determine the physical, chemical, and petrographic properties of these aggregates, including Aggregate Crushing Value (ACV), Aggregate Impact Value (AIV), Los Angeles Abrasion (LAA), Elongation Index (EI), Flakiness Index (FI), specific gravity, water absorption, and unit weight. Additionally, aggregates were subjected to visual and mechanical preparation including washing, drying, sieving, and shape evaluation using thickness and length gauges. Cement consistency was assessed using Vicat’s apparatus. Concrete mixes with constant gradation and water-cement ratios (0.4) were used to cast cylinders. Tests were conducted to measure compressive strengths. Results revealed that the physical properties of aggregates significantly affect concrete strength, particularly when compressive strength exceeds standard values. Among the samples, Balason aggregate exhibited the highest 28-day compressive strength (267.39 kN), followed by Shebok and Pakur, while Kothin Shila showed the lowest strength (123.10 kN). The findings provide essential guidance for engineers in selecting suitable aggregate sources based on the required concrete strength, contributing to more durable and reliable infrastructure in Bangladesh.