原状磷石膏基水硬性胶凝材料的制备与性能表征

Preparation & Characterization of Original Phosphogpsum-based Hydraulic Cementitious Materials

以原状磷石膏(简称磷石膏)、水泥(P.O42.5)、矿渣、粉煤灰为原料,将水泥、矿渣、粉煤灰粉体直接加入磷石膏浆体中进行浆粉搅拌,制备出磷石膏-矿渣-水泥基(PBC)和磷石膏-矿渣-水泥-粉煤灰(PBCF)基水硬性胶凝材料的净浆硬化试样,并对PBC和PBCF净浆硬化试样的性能进行表征。结果表明:PBC试样的3d抗压强度较低,7,28d龄期抗压强度随水泥掺量的增加先增加后降低,水泥掺量20%(质量分数)时,试样的7,28d龄期抗压强度达到最大值,后者为26.4MPa;PBCF试样的7,28d抗压强度随粉煤灰掺量的增加先增加后降低,粉煤灰掺量为15%(质量分数)时,试样的7,28d抗压强度均达到最大值,分别为17.0,28.7MPa;PBCF试样软化系数均≥0.88。

Using the original phosphogypsum slurry (PS), cement (P.O 42.5), blast furnace slag (BFS) and fly ash as raw materials, adding the powder of cement, BFS and fly ash directly to PS to mix them, the specimens of PS-BFS-cement (PBC) and PS-BFS-cement-fly ash (PBCF) based hydraulic cementitious materials were prepared. The properties of specimens of PBC and PBCF were characterized. The results show that the specimens of PBC have the lower compressive strength (CS) of 3 d, and their CS of 7 d and 28 d increase firstly and then decrease with the increase of cement content. The specimens with 20%(mass fraction) cement have the highest value of CS at 7 d and 28 d among all the specimens of PBC, and its CS value of 28 d is 26.4 MPa. CS values of 7 d and 28 d for specimens of PBCF firstly increase and then decrease with the increase of fly ash content. The specimens with 15%(mass fraction) fly ash have the highest value of CS at 7, 28 d among all the specimens of PBCF, which are 17.0, 28.7 MPa respectively. The softening coefficient of specimens of PBCF≥0.88.