【摘要】 为了研究早龄期磷酸钾镁水泥（MKPC）砂浆的抗冻性,测试了在水和5%（质量分数）Na₂SO₄溶液中快速冻融早龄期MKPC砂浆试件的强度、体积变形和吸水率,分析了其物相组成和微观形貌,并将其与水化28 d的MKPC砂浆试件相比较。结果表明,快速冻融循环环境下,早龄期MKPC砂浆试件（水化龄期超过1 d）的强度衰减程度低于水化28 d的MKPC砂浆试件,经受225次冻融循环后,早龄期MKPC浆体试件的剩余强度与28 d水化龄期的MKPC砂浆试件接近,在硫酸盐冻融循环环境下MKPC砂浆试件的强度衰减程度低于水冻融循环环境下的MKPC砂浆试件。早龄期MKPC砂浆试件（水化龄期超过1 d）在冻融循环环境下有较好的抗变形能力,且明显优于水化龄期28 d的MKPC试件。水冻融循环环境下MKPC砂浆试件的抗变形能力优于硫酸盐冻融循环环境下的MKPC砂浆试件。冻融循环过程对水化28 d的MKPC砂浆硬化体孔结构的劣化作用强于水化1 d的MKPC砂浆硬化体。经受硫酸盐冻融循环的MKPC砂浆硬化体的开口孔隙率低于同条件的水冻融循环MKPC硬化体。更多还原

【Abstract】 In order to study the frost resistance of early age magnesium potassium phosphate cement（MKPC） mortar, the strength, volume deformation and water absorption of early age MKPC mortar specimens which were rapidly frozen and thawed in water and 5%（mass fraction） Na₂SO₄ solution were tested, and the phase composition and micro morphology were analyzed. The results were compared with those of MKPC mortar specimens after 28 d hydration. The results show that the strength attenuation degree of early age MKPC mortar specimens（hydration age more than 1 d） is lower than that of hydration 28 d under rapid freeze-thaw cycle environment. After freeze-thaw cycle 225 times, the residual strength of MKPC mortar specimens at early age is close to that of 28 d hydration age specimens, and the strength attenuation degree of MKPC mortar specimens under sulfate freeze-thaw cycle environment is lower than that of MKPC mortar specimens under water freeze-thaw cycle. The early age MKPC mortar specimens（hydration age more than 1 d） have better deformation resistance under freeze-thaw cycle environment, and it is obviously better than that of MKPC with hydration age of 28 d. The deformation resistance of MKPC mortar specimens under water freeze-thaw cycle is better than that of MKPC mortar specimens under sulfate freeze-thaw cycle. The effect of freeze-thaw cycle on the pore structure of MKPC mortar hardened body after 28 d hydration is stronger than that of 1 d hydration. The open porosity of MKPC mortar hardened body subjected to sulfate freeze-thaw cycle is lower than that of water freeze-thaw cycle.更多还原