土聚水泥残留碱浓度的理论计算、测试及其危害性

Theoretical calculation and test of residual alkali concentration consisted of geopolymeric cement and its hazard

对于邻近双硅铝土聚物组成附近的土聚水泥体系,基于反应形成物为双硅铝土聚物的结论,针对土聚反应终点,对不同组成的理论残留碱浓度进行计算,并拟定适宜的方法测定土聚水泥的实际残留碱含量。结果表明,虽然本项目土聚水泥的实际残留碱含量与根据文献报道的土聚水泥组成而计算的理论残留碱含量属同一个等级,但其吸潮泛碱现象却远远超过常规水泥,从而导致其制品上出现严重斑团状色差而根本上破坏装饰效果。这样的泛碱水平相应于土聚水泥对环境土壤的碱性危害。因此,对可能危害绿化植被的工程,诸如公园、街道、道路等场所,土聚类型材料的实际残留碱浓度及碱溶出危害性,均宜测定并妥当评价。

For the geopolymeric cement systems near the composition of the geopolymeric compound poly （sialate-siloxo）,according to the different ends of geo-polymerization reaction,that was determined by means of the following conclusion in literature：the product of the geo-polymerization reaction was poly （sialate-siloxo）,the residual alkali concentrations of geopolymeric cement systems with different compositions were calculated.A suitable testing method of actual residual alkali concentration of geopolymeric cement was put forward.The results showed that the actual residual alkali concentration of geopolymeric cement of this project was in the same level as the theoretical residual alkali concentrations,that were calculated in this paper from some compositions had been published in analogous literature,but its surface alkali frosting,that was caused by its moisture absorption,was much more serious than the ordinary Portland cement.So serious cloud-like tone difference appeared on different regions of geopolymeric cement tiles surface,and then the decorative performance was damaged.The extent of the surface alkali frosting would correspond to the soil alkalization of surrounding soil.Hence,for some engineering projects,such as parks,streets and highways,etc.,the actual residual alkali concentration of geopolymeric cement should be determined and its harmfulness should be evaluated.