水泥基环氧树脂灌浆材料的制备及性能研究

Preparation and properties of cement-based epoxy resingrouting material

以普通硅酸盐水泥P.O 42.5为原料,采用水性环氧树脂(EP)乳液对水泥基灌浆材料进行改性,制备了水泥基环氧树脂灌浆材料,研究了EP掺杂量对灌浆材料的物相结构、微观形貌、力学性能、抗扩散性能和抗氯离子侵蚀性能的影响。结果表明,适量EP添加后延长了灌浆材料的凝结时间,减少了混凝土单位体积用水量,增大了流动度,促进了C—S—H结晶反应的进行。当EP掺杂量为7%(质量分数)时,灌浆材料的流动度达到最大值为293 mm。随着EP掺杂量的增大,灌浆材料早期的抗压强度和抗折强度均降低,后期的抗压强度先增大后降低,抗折强度持续增大。28 d龄期下,当EP掺杂量为7%(质量分数)时,灌浆材料的抗压强度最大为42.15 MPa,抗折强度为12.34 MPa。随着EP掺杂量的增多,灌浆材料的接触角先增大后降低,氯离子扩散系数先降低后增大。当EP的掺杂量为7%(质量分数),在350 min时,灌浆材料的接触角最大为36°,抗扩散性能最优;在养护龄期28 d时,灌浆材料的氯离子扩散系数最低为1.15×10^(-8)cm^(2)/s,抗氯离子侵蚀能力最强。由此可知,EP的最佳掺杂量为7%(质量分数)。

Cement-based epoxy resin grouting material was prepared by modifying the cement-based epoxy resin(EP)emulsion with ordinary Portland cement P.O42.5 as raw material.The effects of EP doping amount on the phase structure,microstructure,mechanical properties,diffusion resistance and chloride ion erosion resistance of the grout materials were studied.The results show that the addition of EP can prolong the setting time of the grouting material,reduce the water consumption per unit volume of concrete,increase the fluidity,and promote the C—S—H crystallization reaction.When the EP content is 7 wt%,the maximum fluidity of the grout material is 293 mm.With the increase of EP doping amount,the compressive strength and flexural strength of the grouting material in the early stage decrease,and the compressive strength in the later stage increases first and then decreases,and the flexural strength continues to increase.At the age of 28 d,when the EP doping amount is 7 wt%,the maximum compressive strength of the grouting material is 42.15 MPa,and the flexural strength is 12.34 MPa.As the amount of EP doping increases,the contact angle of the grouting material first increases and then decreases,and the chloride ion diffusion coefficient first decreases and then increases.When the doping amount of EP is 7 wt%,at 350 min,the maximum contact angle of the grouting material is 36°,and the diffusion resistance performance is optimal.At the curing age of 28 d,the minimum chloride ion diffusion coefficient of the grouting material is 1.15×10^(-8) cm^(2)/s,with the strongest resistance to chloride ion erosion.It can be seen that the optimal doping amount of EP is 7 wt%.