试验将粉煤灰基地聚物混凝土试样分成G1、G2、G3三组,其中G1和G2分别置于清水中和质量分数为5%硫酸钠溶液中进行浸泡试验,同时采用5%硫酸钠溶液对G3组试样进行干湿循环试验。通过监测试样试验过程中的表观形貌变化、质量变化、动弹性模量变化、抗压强度变化,并借助扫描电子显微镜(SEM)对其细微观结构形态上的差异进行了对比分析。结果显示,测试周期内三组试样外观未见任何破损;试样质量最大变化率均较小,G1为1.7%,G2为1.5%,G3为1.2%;G1组动弹性模量下降,G2和G3却呈升高趋势;各组试样的抗压强度均有不同程度的增长,且G1、G2、G3三组的耐蚀系数均大于100%。微观分析发现暴露于硫酸盐环境中的FGC不会产生对结构有害的膨胀性产物。
Fly ash based geopolymer concrete was divided to three groups according to different experimental environment, then put group one (G1)to soak in clear water, soaked group two (G2)in 5% solution of sodium sulfate, group three (G3)were tested in 5% solution of sodium sulfate with dry - wet cycles. Performance of the specimens was evaluated in terms of visual appearance, weight, compressive strength and dynamic elastic modulus.The microstructure of different specimens was also investigated using scanning electron micro - scope(SEM) .Results turn out that there is no damages in appearance of all specimens in the test cycles.The biggest change rate of weight are small, which is 1.7% of G1,1.5% of G2 and 1.2% of G3. The dynamic elastic modulus of G1 is decrease, but G2 and G3 are raise.Compressive strength of the whole specimens show a trend of growth, and the corrosion resistant coefficient are greater than 100%.Meanwhile,microscopic observation show that there is no harmful and expansile product.