Papers by Keyword: CO₂ Curing

Abstract: This study explored the use of Carbide Lime Waste (CLW) in mortar production and its exposure to controlled CO₂ curing for 24 hours. The results indicate that CLW mortar under CO₂ curing has improved compressive strength and early CO₂ capturing performance due to the reaction between Ca (OH)₂ in CLW and CO₂ gas. With a cement replacement rate of 20, a 60% solid carbonates precipitation was recorded after just 7 days of curing. In general, the longer the curing durations, the higher the CO₂ capturing capability. Further investigations into the long-term mechanical and durability properties are recommended to assess its feasibility for practical applications. Re-utilization of waste materials like CLW can make significant strides towards more eco-friendly and sustainable practices.

Abstract: This study was conducted to assess the effect of CO₂ curing on the compressive strength of high strength pervious concrete. The factors studied to evaluate compressive strength of concrete on CO₂ curing pressure, curing time, and age of specimen at testing. Three Aggregate sizes, three CO₂ curing pressures, three CO₂ curing time, and three testing ages were used in this investigation. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. The 1-day compressive strength has a major impact after CO₂ curing and their strength decreased by about 0% to 50% as compared to the control group. However, it is observed that there is only slight difference in relationship between modulus of elasticity and compressive strength obtained from 100 by 200mm cylinders with CO₂ curing.

Abstract: In this project, a process was developed to cure concrete masonry blocks using CO2. It was found that the strength of concrete mixtures for block manufacture after CO2 curing was close to that after conventional steam curing. A dry pre-conditioning before CO2 curing was very critical to achieve high degree of CO2 curing. The specimen pre-conditioned in the moist environment hydrates more than those pre-conditioned in the dry environment during the pre-conditioning period. However, much less CaCO3 formed in the former that that in the latter after the CO2 curing. Thus, the CO2 curing is mainly contributed by the reactions between CO2 gas and cement clink minerals.