Title:
Mechanical and Microstructural Insights into the Coral Aggregate, Seawater, and Bentonite Clay Reinforced Concrete Under Sulfate Attack
Author(s):
Zahoor Hussain
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
11/3/2024
Abstract:
The scarcity of natural construction materials and freshwater reservoirs has driven global interest in tailoring concrete from sea-based materials. This study investigates the durability aspects of concrete formulated with coral aggregate, seawater, sea sand, and bentonite clay under sulfate attack. Microstructural characterization using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and micro-computed tomography (M-CT) was performed after prolonged sulfate exposure. Concurrently, mechanical properties were evaluated through compressive strength tests at 28, 56, 90, and 180 days after casting. M-CT results revealed increased porosity with higher proportions of sea-based materials, while SEM-EDS corroborated the quantitative analysis. Compressive strength exhibited an improving trend with replacements up to 24% of the original composition. The findings demonstrate that incorporating seawater in bentonite-added cement with 24% partial sea sand and coral aggregate replacements, alongside fly ash, enhances pozzolanic activity during cement hydration, promoting increased calcium-silicate-hydrate (C-S-H) gel formation. This dense microstructure contributes to effective microstructural properties, providing mechanical strengths comparable to referenced freshwater Portland concrete matrices. Furthermore, bentonite clay improves the microstructure by filling pores, minimizing the sulfate attack's effect. The concluded replacements create environmentally friendly composites with effective microstructural properties, balancing structural performance and sustainability while exploring sustainable construction material alternatives.