石膏基发泡保温材料的性能与结构研究

The performance and structure research of gypsum-based foam insulation material

以建筑石膏为基材,加入矿渣、普通硅酸盐水泥和添加剂改性,外掺少量生石灰、缓凝剂等,通过物理发泡工艺制备石膏基发泡保温材料。研究了不同外加剂(缓凝剂和碱性激发剂)对石膏基复合胶凝材料物理性能的影响,测试了石膏基发泡保温材料的导热系数和热工性能。采用XRD、TG-DTA和ESEM等分析手段分别研究了石膏基复合胶凝材料的相结构、热稳定性和相组成。结果表明:石膏基发泡保温材料具有导热系数低、强度高等优良性能;石膏基复合胶凝材料以二水石膏(CaSO_4·2H_2O)和钙矾石(AFt)为结构骨架,C-S-H凝胶、硬硅钙石[Ca_6Si_6O_(17)(OH)_2]等含量越高,结构越致密,材料的物理力学性能越好。

The gypsum-based foam insulation material was prepared by using physical foaming process and taking calcined gypsum as base material,adding slag, ordinary Portland cement and additives modification,mixed with small amount of CaO,retarder and so on. The impact of admixture （retarder and alkaline exciting agent） on the macro-physical properties of gypsum-based ce- menting composite was studied with comparative experiments,the thermal conductivity coefficient and the product thermal perfor- mance of gypsum-based insulation material was tested. The phase composition, thermostability and phase structure of the gypsum- based cementing composite are respectively studied by XRD,TG-DTA and ESEM analysis. The experimental result have shown that the gypsum-based foam insulation material have low thermal conductivity, high strength, and other good properties. Furthermore,the calcium sulfate dehydrate（CaSO4·2H20） and ettringite（AFt） are basic structural skeleton of the hydration hardening body,the high- er content of calcium silicate hydrate（C-S-H） and xonotlite [CooSirO17（OH）E],the more compact to the structure,the better physical and mechanical property to the gypsum-based composite.