粉煤灰改性磷酸镁水泥试验研究

分析了水灰比、粉煤灰掺量对MPC试件强度的影响。净浆试件最优水灰比为0.13时,1 d抗折、抗压强度分别为8.0、30.2 MPa,28 d抗折、抗压强度分别达到10.3、53.1 MPa,达到P·O 52.5R的强度要求,具有明显的早强、高强特性。改性试件中粉煤灰的最优掺量为10%,最优水灰比为0.17。改性试件1 d抗折、抗压强度分别为5.3、25.9 MPa,达到P·O 42.5R的强度要求,早强特性明显。电镜扫描形貌表明,产物中MKP晶体排列致密;但粉煤灰将破坏晶体排列,导致强度降低。

Research of mixing ratio and fly ash modification ofm agnesium phosphate cement

The effect of water-cement ratio and the optimal content of fly ash on the strength of the specimen was analyzed.When the water-cement ratio of the specimen is 0.13,the strength of the specimen reaches the requirement of P·O 52.5R.The 1 d flexural strength and compressive strength of MPC specimens were 8.0 MPa and 30.2 MPa respectively.The 28 d flexural and compressive strength of MPC specimens were 10.3 MPa and 53.1 MPa respectively.The characteristics of early strength and high strength of MPC specimen are obvious.The influence of fly ash content on the specimen was analyzed.The optimal content of fly ash is 10%,the corresponding water-cement ratio is 0.17,and the strength of the specimen reaches the requirement of P·O 42.5R.Fly ash destroys the arrangement of the MKP crystals,resulting in a decrease in the strength of the specimen.The 1 d flexural strength and compressive strength of modified specimens were 5.3 MPa and 25.9 MPa respectively.Electron microscope scanning morphology shows that,the density of MKP crystals in the specimen is densely arranged.However,fly ash will destroy the crystal arrangement,resulting in reduced strength.