负温环境下磷酸二氢钠对磷酸镁水泥力学性能的影响

Effect of Sodium Dihydrogen Phosphate on Mechanical Properties of Magnesium Phosphate Cement under Negative Temperature Environment

采用磷酸二氢钠(SDP)部分替代磷酸二氢钾制备磷酸镁水泥,研究磷酸二氢钠对磷酸镁水泥负温环境早期力学性能的影响。研究结果表明,磷酸二氢钠可以缩短磷酸镁水泥凝结时间,当磷酸二氢钠用量质量分数达到75%时,磷酸镁水泥净浆的最终凝结时间为6 min 30 s。-10℃环境下,当磷酸二氢钠完全替代磷酸二氢钾时,MPC基材料的增强效果最好,但凝结时间却最短,不足6min。复合磷酸二氢钠和磷酸二氢钾可提高MPC的早期抗折强度及粘接强度,且磷酸二氢钠的质量分数在0~50%,粘接强度随着磷酸二氢钠含量的增加而增加;当磷酸二氢钠质量分数高于50%时,粘接强度开始下降。

Sodium dihydrogen phosphate(SDP)as a partial substitute for potassium dihydrogen phosphate was used to prepare magnesium phosphate cement,and the effect of sodium dihydrogen phosphate on the early mechanical properties of magnesium phosphate cement was studied.The research results indicated that sodium dihydrogen phosphate could shorten the setting time of magnesium phosphate cement.When the dosage of sodium dihydrogen phosphate reached 75%,the final setting time of magnesium phosphate cement slurry was 6 min and 30 s.At-10℃,when sodium dihydrogen phosphate completely replaced potassium dihydrogen phosphate,the MPC based material had the best reinforcement effect,but the setting time was the shortest,less than 6 min.Composite sodium dihydrogen phosphate and potassium dihydrogen phosphate could improve the early flexural strength and bonding strength of MPC,and the dosage of sodium dihydrogen phosphate was in the range of 0 to 50%,the bonding strength increased with the increase of sodium dihydrogen phosphate content;when the content of sodium dihydrogen phosphate exceeded 50%,the bonding strength began to decrease.