Performance and Mechanism Analysis of Magnesium Phosphate Cement Modified by Fly Ash
Magnesium phosphate cement(MPC)was prepared with fly ash,MgO and KH2PO4 as raw materials.The compressive strength,flexural strength,setting time and porosity of MPC under different fly ash contents were measured,and the microstructure was analyzed.The test results show that the compressive strength of MPC increases first and then decreases with the increase of fly ash content.When the fly ash content is 20%,the maximum compressive strength is 34 MPa.The flexural strength decreases with the increase of fly ash content,and the toughness also decreases with the increase of fly ash content.The addition of fly ash improves the pore structure of MPC,and when the fly ash content is 40%,the porosity of MPC decreases by 67.2%.Fly ash prolongates MPC setting time,and the setting time extends to 13.7 min when the fly ash content is 40%.With the increase of fly ash content,the production of hydration product MgKPO4·6H2O(MKP)increases first and then decreases,and the MKP production is the largest when the content is 20%.The effect of fly ash on the MPC strength mainly depends on the MKP production.
国家科技期刊平台
NSTL
万方数据
维普
