An experimental Study on the Effect of Sodium Chloride(NaCl) on Tandur Slurry Powdered Mortar Cubes

Durability and Mechanical Performance of Sustainable Mortar

Abstract

The construction industry’s pursuit of sustainable practices has intensified the search for supplementary cementitious materials. This study explores the viability of Tandur Slurry Powder (TSP), a waste byproduct from limestone polishing, as a partial replacement for Ordinary Portland Cement (OPC) in mortar, with a focus on resistance to sodium chloride (NaCl) attack. Mortar cubes were prepared with 0%, 20%, 40%, and 60% TSP replacement by weight. After 28 days of water curing, the cubes were subjected to NaCl solutions of varying concentrations (1%, 3%, 5%) for 7, 14, and 28 days. The mechanical and durability properties were evaluated through compressive strength tests, weight loss measurement, water absorption, and Ultrasonic Pulse Velocity (UPV). Results indicate that a 20% TSP replacement yielded the highest compressive strength (~32.8 MPa) before chemical exposure. However, under NaCl attack, strength loss increased proportionally with higher TSP content and longer exposure duration, with the most severe degradation (~37% loss) observed in 60% TSP samples exposed to 5% NaCl for 28 days. While TSP incorporation increased water absorption, the study concludes that TSP can be effectively utilized up to 20% replacement in applications with low risk of chloride attack, offering a promising avenue for waste valorization and reduction of cement consumption.