基于Rietveld/XRD(内标法)水泥浆体物相演变定量表征与晶定量公式非修正

Quantitative Characterization for Phase Evolution of Cement Paste Based on Rietveld/XRD(Internal Standard Method) and Correction Formula for Amorphous Phase

基于Rietveld/XRD精修方法,借助GSAS-EXPGUI软件,研究既定水化龄期普通硅酸盐水泥浆体物相组成的定量表征,并结合Ca(OH)2的热分析定量结果以及熟料矿物与自由水的量化匹配关系研究Rietveld定量结果的可靠性。研究结果表明,干燥水化样品中Ca(OH)2的Rietveld定量结果与热分析定量结果具有较好的一致性,当水化1 d、3 d、7 d和28 d龄期时,其绝对误差分别为1. 2%、0. 7%、0. 3%和0. 8%,且随着水化龄期的延长,样品的相对误差显著降低。结合水泥浆体物相演变的Rietveld定量表征发现,熟料矿物的消耗程度与自由水的消耗程度存在较好的线性相关性(相关系数R2=0. 996),反映了其Rietveld定量表征具有较高的可靠性。在此过程中,提出了基于内标法改进型的非晶相定量公式,并建立了水泥浆体自由水与相应干燥样品化学结合水的数学关系。

Based on Rietveld/XRD method,the quantitative characterization of the phase composition for ordinary Portland cement paste at a given hydration was investigated via GSAS-EXPGUI software,and the reliability of the quantitative results was further probed by combining with the thermal analysis of Ca(OH) 2 ,as well as the quantitative matching relationship of clinker minerals and free water.The results indicated that the Rietveld quantitative results of Ca(OH) 2 in dry hydration samples agreed well with that of the thermal analysis,their absolute errors were 1.2%,0.7%,0.3% and 0.8% when hydrated for 1 d,3 d,7 d and 28 d ages,respectively.Besides,the relative errors were significantly decreased with the increase of hydration age.It was found that there was a satisfactory linear correlation (correlation coefficient R^2 =0.996) between the degree of consumption of clinker minerals and free water,reflecting the high reliability of Rietveld quantitative characterization.In this process,an ameliorated amorphous phase quantitative formula based on the internal standard method was proposed,and the mathematical relationship between the free water of cement paste and the chemical bonding water of corresponding drying samples was established.