水性环氧树脂对铁尾矿加气混凝土力学性能及抗冻性的影响

Effects of Waterborne Epoxy Resin Content on Mechanical Properties and Frost Resistance of Aerated Concrete Prepared with Iron Tailings

目的研究水性环氧树脂的掺量对铁尾矿加气混凝土的吸水率、密度、抗压强度、冻融后的质量损失率和抗压强度损失率的影响.方法通过掺入不同掺量的水性环氧树脂制备铁尾矿加气混凝土试样,经冻融循环后,测试其质量损失和强度损失,重点分析水性环氧树脂掺量对加气混凝土抗冻性能的改善作用,并利用XRD和SEM等分析方法,研究不同掺量下加气混凝土试样的水化产物及结构特点.结果水性环氧树脂较为适当的掺量范围为3%~5%.当水性环氧树脂掺量大于3%时,制备试样的吸水率较为明显的降低;制备试样的密度有较大幅度的升高.当水性环氧树脂掺量为3%时,制备试样15次冻融循环后的质量损失率和抗压强度损失率开始较为明显的降低;当水性环氧树脂掺量大于3%时,试样的质量损失率和抗压强度损失率的降幅逐渐减小.结论当水性环氧树脂掺量为3%时,对加气混凝土的抗冻性开始起作用,15次冻融后试样的质量损失率和强度损失率分别为3.981%和20.019%;水化产物以托勃莫来石、C-S-H(II)和复合的交联的胶凝材料相为主.

This paper studied effects of waterborne epoxy resin content on water absorption rate, density, compressive strength,loss tare of mass and compressive strength of aerated concrete pre- pared with iron tailling. Aerated concrete samples were made by controlling the content of water- borne epoxy resin. Then loss rates of their mass and compressive strength were tested after freez- ing-thawing cycles and influences of different waterborne epoxy resin content on the frost resistance of aerated concrete were studied. Using XRD and SEM methods, hydration products and structural characteristics of aerated concrete with different content were analyzed. It is found that the appropriate content range of waterborne epoxy resin is 3 % ~ 5 %. When the content of water- borne epoxy resin is 3% ,loss rates of mass and strength after 15 freezing-thawing cycles begin to decrease clearly. When the content of waterborne epoxy resin is greater than 3 %, water absorption rates of samples decrease obviously, densities increase in a large extent and the decline of loss rates of mass and strength gradually decrease. Conclusion is that the frost resistance of aerated concrete begins to be improved, when the content of waterborne epoxy resin is 3 %. The loss rates of mass and compressive strength after 15 freezing-thawing cycles are 3.981% and 20. 019% ,respective- ly ;the hydration products mainly contain Tobermorite ,C-S-H(II) and composited cross-linked ce- mentitious phase.