磷酸钾镁水泥浆体早期变形机制

Early Deformation Mechanism of Magnesium Potassium Phosphate Cement (MKPC) Paste

为了探究新拌磷酸钾镁水泥(MKPC)基浆体的早期变形机制,利用自制气球装置测试参考样(F0) 1 d以内的膨胀率来验证试验的可行性,同时测试了不同粉煤灰掺量的磷酸钾镁水泥(MKPC)浆体1 d以内的塑性变形、强度、水化温度,分析了MKPC浆体的物相组成和微观形貌。结果表明:(1)该试验方法所得结果有较好的重复性和复现性;(2) MKPC浆体从加水拌和至测试历时10 min,水化10 min开始至水化2 h体积迅速膨胀,之后MKPC浆体的体积膨胀率逐渐下降,直至1 d达到稳定状态;(3)水化24 h时,F0的体积膨胀率为0. 26×10^(-2),粉煤灰掺量为10%、20%、30%(代号FA10、FA20、FA30)的MKPC浆体较F0的膨胀率分别增加了181. 98%、199. 81%和155. 97%。

To explore the early deformation mechanism of the fresh phosphate-potassium phosphate cement(MKPC)paste,the study used a homemade balloon device to test the expansion rate within a reference sample(F0)within 1 d to verify the feasibility of the test.The plastic deformation,strength and hydration temperature of the magnesium phosphate cement(MKPC)paste with different fly ash content were tested,and the phase composition and microstructure of MKPC paste were analyzed.The results show that:(1)The results obtained by this experimental method have good repeatability and reproducibility.(2)The MKPC paste was mixed with water until the test lasted 10 min,and the volume of the MKPC pasted rapidly expanded from 10 min to 2 h of hydration,after the volume expansion ratio of the MKPC paste gradually decreased until it reached a steady state at 1 d.(3)When the hydration 24 h,the volumetric expansion rate of F0 is 0.26×10^-2,MKPC paste with different fly ash content of 10%,20%,and 30%(codes FA10,FA20,FA30)is higher than that of F0,compared with the reference F0 expansion rate increased by 181.98%,199.81%and 155.97%.