Development of High Early Strength Grout System using Brick Dust for Preplaced Aggregate Concrete

Abstract

This study investigates the use of brick dust (BD) as a supplementary cementitious material (SCM) for high early strength grout systems, specifically designed for rapid repairs of civil and military infrastructure where open time is limited. A comprehensive evaluation of BD's pozzolanic activity and its effects on fresh and hardened state grout properties was conducted through powder characterization, flow, flexure, compressive strength, strength index, modified Chapelle's test, and BET test. The results demonstrate that BD improves strength, durability, and making it a suitable SCM for high early strength grout systems. Notably, formulations F11, containing 5% BD, 30% fly ash (FA), and 10% ordinary Portland Cement (OPC) in replacement of Calcium Aluminate Cement (CAC), exhibit promising results with 28 MPa compressive strength achieved in just 1 hour. This offers a potential solution for immediate repairs where rapid strength gain and reduced open time are critical. XRD and SEM analysis reveal that the addition of these SCMs increases the availability of silicate sites, leading to the production of more calcium aluminate silicate hydrates, which governs the reduction of strength degradation factors associated with CAC. The incorporation of BET test results further supports the improved pozzolanic activity of BD, showcasing its potential to enhance grout performance in demanding applications. The findings of this study contribute to the development of sustainable and efficient repair materials for critical infrastructure."