改性水滑石对砂浆氯离子固化性能的影响

Effect of modified hydrotalcite on solidification properties of chloride ions in mortar

对水滑石进行了煅烧改性,并分析了煅烧温度(500、600、850℃)对水滑石微观性能的影响。研究了单Cl^(-)模拟海水体系和Cl^(-)、SO_(4)^(2-)共存模拟海水体系下,改性水滑石掺量(0、3%、5%、7%)对砂浆氯离子固化能力、抗压强度的影响,同时进行了机理分析。结果表明:水滑石经过煅烧后会失去CO_(3)^(2-),导致层间位置空缺,最佳煅烧温度为500℃;与Cl^(-)、SO_(4)^(2-)共存模拟海水体系相比,单Cl^(-)模拟海水体系下的氯离子固化率较大;随着改性水滑石掺量的增加,砂浆的氯离子固化率增大,抗压强度先增大后减小;综合考虑,改性水滑石最佳掺量宜为3%。

The modification of hydrotalcite was carried out through calcination,and the influence of calcination temperature(500,600,850℃)on the microstructure properties of hydrotalcite was analyzed.The effects of modified hydrotalcite content(0,3%,5%,7%)on the chloride ion solidification ability and compressive strength of mortar under single Cl^(-)simulated seawater system and Cl^(-)and SO_(4)^(2-)coexisting simulated seawater system were studied,and the mechanism was analyzed.The results show that after calcination,hydrotalcite will lose CO_(3)^(2-),leading to interlayer vacancy,and the optimal calcination temperature is 500℃.Compared with the Cl^(-)and SO_(4)^(2-)coexisting simulated seawater system,the chloride ion solidification rate is higher in the single Cl^(-)simulated seawater system.With the increase of modified hydrotalcite content,the chloride ion solidification rate of mortar increases,and the compressive strength first increases and then decreases.Taking all factors into consideration,the optimal content of modified hydrotalcite should be 3%.