温度和相对湿度对CO2养护钢渣制品性能的影响

Effect of Temperature and Relative Humidity on Performance of CO2 Curing Steel Slag Products

摘要:

通过响应面法 （RSM） 研究了温度和相对湿度对CO₂养护钢渣制品（以下简称钢渣制品）性能的影响.结果表明：温度和相对湿度的相互作用对钢渣制品碳化过程的影响在不同碳化阶段有所不同.CO₂养护初期，CO₂的扩散是关键因素，但该阶段碳化不充分；CO₂养护后期，钢渣制品的抗压强度和碳化程度受Ca²⁺和CO₂溶解度的影响较大.当相对湿度低于30%时，尽管CO₂扩散较快，但其溶解度低，限制了CO32-与Ca²⁺的反应，导致钢渣制品无法达到理想的强度和碳化水平.将温度和相对湿度分别提至70 ℃和64%，可以促进更多纳米级CaCO₃形成，填充了40~180 nm孔隙，有效减小了钢渣的孔径和孔体积，从而改善了材料性能.

Abstract:

The response surface methodology （RSM） was employed to investigate the effects of temperature and relative humidity on the performance of steel slag products under CO₂ curing （hereafter referred to as steel slag products）. The results show that the interplay between temperature and relative humidity variably influences the carbonation process at different stages. During the initial stage of carbonation， CO₂ diffusion emerges as a pivotal factor， albeit with incomplete carbonation. In the later stages， compressive strength and carbonation degree are predominantly affected by the solubility of Ca²⁺ and CO₂. Notably， when relative humidity falls below 30%， despite rapid CO₂ diffusion， the low solubility hampers the reaction between CO32- and Ca²⁺， preventing the attainment of desired strength and carbonation levels. Increasing the temperature and relative humidity to 70 ℃ and 64%， respectively， the formation of nanoscale calcium carbonate is fostered， significantly reducing pore size and volume in steel slag by filling voids ranging from 40 nm to 180 nm， thereby enhancing material properties.