| dc.description.abstract | The rapid industrial development in today′s world has resulted in a significant increase in greenhouse gas emissions, leading to frequent occurrences of extreme weather events and exacerbating the greenhouse effect. Therefore, the reduction and mitigation of carbon dioxide production have become the motivation for this research. In this study, carbon dioxide accelerated curing and the partial replacement of cement with bottom ash and fly ash were employed to achieve carbon sequestration in concrete. Cubic concrete specimens measuring 40×40×30 centimeters were prepared with molds for carbon curing. Core samples were obtained for experimental testing, and the specimens were divided into upper, middle, and lower layers for analysis. The experimental tests included rebound hammer, compressive strength, modulus of elasticity, neutralization, water absorption, and ultrasonic wave velocity measurements. Additionally, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were employed to examine the microstructure of concrete and investigate the engineering properties of the carbon curing group compared to the control group (water curing).
The experiments were conducted with non-carbonated plain concrete as the control group. The results showed that the compressive strength of each concrete specimen at the age of 7 days, compared to the control group, yielded relative values. The compressive strength of the upper concrete specimens in the carbon curing group was 26.1% higher than that of the control group. At the age of 7 days, the overall compressive strength of the bottom ash and fly ash concrete was relatively lower, but at the age of 90 days, the compressive strength of both groups exceeded or approached that of the control group. At the age of 7 days, the upper layer′s modulus of elasticity in the high-strength and low-strength plain concrete specimens after carbon curing was 27.0% and 21.9% higher than that of the control group, respectively. At the age of 90 days, the modulus of elasticity was similar to that of the control group, with relative percentages of -2.7% and -5.3% respectively. The maximum neutralization depths of the bottom ash and fly ash concrete were 1.744mm and 1.586mm, respectively. The water absorption of each carbon-cured concrete specimen decreased at the age of 7 days, and at the age of 90 days, the water absorption of the bottom ash and fly ash concrete decreased by -5.6% to -38.1% compared to the control group. The differences in ultrasonic wave velocity between the carbon-cured concrete specimens and the control group were below 10%. EDS and XRD analyses revealed the presence of calcium carbonate. | en_US |