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采用水胶比0.45的净浆、砂浆和混凝土材料,以水蒸气等温吸附法和压汞法为试验方法,以GAB吸附模型为数据分析手段,通过等温吸附曲线、脱附曲线、滞回曲线和孔隙分布,研究使用水蒸气等温吸附法表征水泥基材料的孔隙结构。研究结果表明:骨料对水泥基材料的水蒸气等温吸附曲线几乎没有影响;水泥基材料吸附/脱附滞回曲线出现在整个湿度区域,并在湿度为80%达到最大值;考虑表面吸附层能够提高水蒸气等温吸附计算的孔隙分布精度;水蒸气等温吸附法得到的孔隙率和比表面积与压汞法得到的数值具有正相关性;微孔(r<3nm)中能量不稳定和显孔(r>3nm)中"墨水瓶"效应是水蒸气等温吸附过程滞回现象的主要原因。
Abstract：Using water vapor sorption isotherm(WVSI) and mercury intrusion porosimetery(MIP) and equilibrium isotherm model of Guggenheim-/Andersen-de Boer(GAB),the WVSI data were used to characterize the pore structure of blended paste,mortar and concrete with water-binder of 0.45.The adsorption,desorption and hysteretic curves of WVSI,and the pore size distribution(PSD) by both WVSI and MIP were analyzed.The results show that the aggregates have little effect on the adsorption and desorption WVSI curves.The adsorption/desorption hysteresis occurs in the whole range of relative humidity(RH) with the maximum hysteresis at RH of 80%.The adsorbed layer can improve the accuracy of PSD from WVSI data.The specific surface area and porosity from WVSI data are comparable with those from MIP.The energy instability in micro-pores(< 3 nm) and the ‘ink-bottle' effect in micro-pores(> 3 nm) can account for the adsorption/desorption hysteresis.
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基本信息:
中图分类号:TU528
引用信息:
[1]罗明勇,曾强,庞晓贇,等.水蒸气等温吸附表征水泥基材料孔隙结构[J].硅酸盐学报,2013,41(10):1401-1408.
基金信息:
国家自然科学基金[50978144(2010-2012)]项目
2013-09-24
2013-09-24
2013-09-24