外掺料对磷石膏基胶凝材料力学及导热性能的影响

将磷石膏应用于建筑业，可以解决磷化工副产物堆积的问题。采用单因素实验，通过改变水灰质量比、粉煤灰掺量、生石灰掺量等条件来研究各因素对磷石膏基胶凝材料力学性能及保温性能的影响，借助X射线衍射（XRD）、X射线荧光光谱（XRF）、扫描电镜（SEM）等手段来分析磷石膏基胶凝材料的物化性质和形貌结构。结果表明，磷石膏基胶凝材料的导热系数和抗压强度都与水灰质量比呈负相关，在水灰质量比为0.250时胶凝材料的抗压强度最大、水灰质量比为0.550时胶凝材料的导热系数最小；粉煤灰在磷石膏基胶凝体系中除了提供胶凝性能外，还会被生石灰激发出活性，增强胶凝体系的综合性能，粉煤灰掺量为50%（质量分数）时胶凝体系的综合性能最佳；生石灰在磷石膏基胶凝体系中对杂质的吸附效果明显，生石灰掺量超过7%（质量分数）以后对胶凝体系的保温性能和力学性能的增强效果明显。

Effect of external admixtures on mechanical and thermal conductivity of phosphogypsum composite cementitious materials

Application of phosphogypsum in construction industry can solve the problem of accumulation of phosphorus chemical by?products.Single factor experiment was used to study the effects of various factors on the mechanical properties and thermal insulation properties of phosphogypsum?based cementitious materials by changing the water?cement mass ratio，the content of fly ash and the content of quicklime.The physicochemical properties and morphology of phosphogypsum-based cementitious materials were analyzed by means of X-ray diffraction（XRD），X-ray fluorescence spectroscopy（XRF） and scanning electron microscopy（SEM）.The results showed that the thermal conductivity and compressive strength of phosphogypsum?based cementitious materials were negatively correlated with the water?cement mass ratio.When the water cement ratio was 0.250，the compressive strength of the cementitious material was the largest，and the thermal conductivity of the cementitious material was the smallest when the water?cement mass ratio was 0.550.Fly ash in phosphogypsum?based cementitious system not only provided cementitious performance，but also was activated by quicklime to enhance the comprehensive performance of the cementitious system.When the content of fly ash was 50%（mass fraction），the comprehensive performance of the cementitious system was the best.The adsorption effect of lime on impurities in phosphogypsum-based cementitious system was obvious.When the content of lime was more than 7%（mass fraction），the thermal insulation performance and mechanical properties of the cementitious system were obviously enhanced.