Controlling Drying Shrinkage of Concrete Block using By-Product Materials and Fibers

Abstract

Utilizing by-products and fibers in concrete blocks can effectively control drying shrinkage and enhance mechanical properties while promoting sustainability. This study evaluates the feasibility of incorporating by-products such as construction waste, brick dust, waste cement fines (WCF), ladle furnace slag and recycled block materials and impact of incorporating jute and polypropylene fibers, into concrete blocks. The primary objective is to reduce drying shrinkage and improve compressive strength. Methodologies included the Compressive Strength Test, Modulus of Rupture Test, Permeable Voids and Boiling Water Absorption Test and Linear Drying Shrinkage Test. Results indicated that incorporating by-products decreased linear drying shrinkage and boiling water absorption, with varying effects on void content and a general increase in strength. Specifically, brick dust and WCF significantly reduced shrinkage and increased strength, while jute and polypropylene fibers showed mixed results. Jute fibers at a 0.3% dosage and 15 mm length provided higher strength in specific cases. The study concluded that optimizing mix proportions, curing conditions and fiber dispersion is crucial for performance enhancement. Higher temperatures increased shrinkage, while low temperatures and high humidity reduced it. Polypropylene fibers exhibited higher shrinkage compared to jute fibers. Future research should focus on improving fiber dispersion and exploring hybrid fiber systems to further enhance the mechanical properties and durability of concrete blocks.