磷石膏-矿渣基胶凝材料的制备及其性能研究

针对磷石膏基胶凝材料强度低、耐水差的缺点，运用碱激发剂改善磷石膏基胶凝材料的力学性能和耐水性。采用扫描电镜、X射线衍射和压汞法分析磷石膏基胶凝材料水化产物和孔结构。结果表明：将磷石膏在140 ℃条件下热活化4 h后得半水石膏，按m（半水石膏）∶m（矿渣）∶m（生石灰）=60∶40∶4配制粉料，水胶质量比为0.6，掺1%（质量分数）的碱激发剂，磷石膏基胶凝材料抗压强度和抗折强度分别为40.6 MPa和11.3 MPa，软化系数为0.84；硬化体中二水石膏和钙矾石为基本骨架，C-S-H凝胶包覆各组分形成致密网状结构，保证材料高强高耐水性。

Study on preparation of phosphogypsum-slag-based cementing material and performance thereof

In allusion to the low strength and poor water resistance of phosphogypsum-based cementing material，alkaline activator was applied in improving its mechanical properties and water-resistance.Hydration products and pore structure were characterized by using scanning electron microscope，X-ray diffraction，and mercury porosimetry.Results showed that hemihydrate calcium sulfate which was obtained by calcining phosphogypsum at 140 ℃ for 4 h was doped with slag and lime according to the mass ratio of 60∶40∶4，the mass ratio of water to binder was 0.6，and 1%（mass fraction） alkali activator was added，and then phosphogypsum-slag-based cementing material was prepared，the compressive strength and flexure strength reached 40.6 MPa and 11.3 MPa，respectively，and the softening coefficient was 0.84；the structure frameworks of calcium sulfate dehydrate and ettringite with the dense network structure of C-S-H gel which enfolded each component had high performances on mechanics and water resistance.