磷酸镁水泥混凝土耐久性试验研究

Experimental Study on Durability of Magnesium Phosphate Cement Concrete

系统研究了磷酸镁水泥混凝土的干缩、耐水、抗渗和耐腐蚀性能。结果表明,磷酸镁水泥经复配10%普通硅酸盐水泥、10%粉煤灰、5%生石膏、0.3%多聚磷酸钠后,砂浆干缩率大幅降低,混凝土干缩率早期高、后期低。磷酸镁水泥混凝土耐水性较差,掺入硅溶胶或HEA防水剂可显著改善其耐水性,同时可显著提高其抗渗性,由于孔隙率降低和孔隙结构得到显著改善,硅溶胶改善抗渗性的效果更佳。氯盐与硫酸盐腐蚀试验结果表明,磷酸镁水泥混凝土具有较好的耐腐蚀性能。

Shrinkage,water resistance,penetration resistance and corrosion resistance of magnesium phosphate cement（ MPC） concrete were systematically investigated. The results indicated that the shrinkage of MPC mortar was significantly reduced by blending with 10% ordinary portland cement,10%fly ash,5% gypsum and 0. 3% sodium polyphosphate. And the shrinkage of MPC concrete was featured with high value in the earlier period but low value in the later stage. Inferior water resistance of MPC concrete could be observed which could be substantially improved by silica sol or HEA water-proof agent.In addition,the penetration resistance of MPC concrete was greatly enhanced due to the addition of silica sol or HEA. Silica sol seemed better in terms of improving the penetration resistance due to the reduction of porosity and modification of pore structures. The chloride and sulfate soaking testing results showed that MPC concrete was favorable in the environment of chloride or sulfate attack.