Exploring new pre-curing methods for carbonation curing of cement-based materials

Abstract

Pre-curing is a crucial step in the carbonation curing of cement-based materials. It significantly influences the subsequent carbonation and hydration processes, carbon sequestration efficiency, and strength development. This study investigates the effects of various pre-curing methods (fan drying, oven drying, microwave drying) and curing regimes on carbonation performance in cement-based materials using a custom monitoring system that tracks carbonation degree, temperature, and humidity in real time. Experimental results demonstrate that oven and microwave pre-curing accelerate moisture loss while enhancing pre-hydration. Reduced pre-hydration time (24 h) and lower residual water-cement ratio (0.4) optimized CO₂ diffusion and calcium carbonate crystallization, achieving 29.80 % carbonation degree. Although carbonation products limited subsequent hydration, compressive strengths at 3, 7, and 28 days increased by 2.8 %, 5.1 %, and 7.1 % compared to standard-cured samples. The findings provide insights for optimizing carbonation curing processes through controlled pre-curing conditions.