Performance Evaluation of Sand-Crete Mortar Units Containing Burnt Brick Waste in Flood-Prone Environment

This study explored using Burnt Brick Waste (BBW) to partially replace sand in mortar production, aiming to enhance strength, durability, and performance in flood-prone areas. BBW, a byproduct of brick production, was tested at replacement levels from 0% to 50% in 10% increments. A 1:6 mix ratio was used to produce 450 × 225 × 150mm hollow blocks with a web thickness of 37.5 mm, meeting the Nigeria Industrial Standard for 6-inch load-bearing blocks. Tests on 72 block samples evaluated compressive strength at various ages, 54 blocks for water absorption, and 18 cylindrical specimens for sorptivity. SEM-EDX analysis was employed to understand performance mechanisms. Results showed that higher BBW replacement increased compressive strength but also increased water absorption and sorptivity rates compared to control samples, though these rates decreased with age. SEM-EDX analysis indicated increased pore sizes with lower BBW replacement, enhancing strength but reducing durability due to the clay's high-water affinity in burnt bricks. Flood simulation tests revealed that mortar units with 10% and 20% BBW had reduced compressive strength compared to controls after a 10-day simulation. The study recommends limiting BBW replacement to 10% for optimal strength and durability in flood-prone areas. It also suggests reusing burnt bricks from house renovations in mortar, reducing construction costs, improving strength without affecting durability, and decreasing waste at brick factories. This practice also offers ecological benefits by reducing dependence on sandy soil for construction, mitigating environmental damage.