超高韧性粉煤灰基地聚合物的研制及性能

Preparation and Performance of Ultra high Toughness Fly Ash Based Geopolymer

摘要:

以粉煤灰为主要原材料设计研制超高韧性粉煤灰基地聚合物（FAEGC），确定其最优配合比，并研究养护龄期、预加拉伸应变和反应温度对FAEGC抗压强度、表观密度、拉伸性能及微裂纹特征的影响.结果表明：在水灰比为035，水玻璃模数为15且掺量为6%（以Na2O质量计），以及聚乙烯醇（PVA）纤维体积分数为1%时，试件可产生明显应变硬化特性，且最大拉伸应变达到47%；随着养护龄期的延长，FAEGC的拉伸强度不断提高，但养护龄期的延长对其最大拉伸应变有不利影响；当预加拉伸应变相同时，随着龄期的延长，FAEGC的裂纹总数增加，平均裂纹宽度减小；当龄期相同时，随着预加拉伸应变的增加，FAEGC的裂纹总数和平均裂纹宽度均增加；在高温反应环境下，FAEGC的抗压强度、初裂强度和拉伸强度分别提高了6%，60%和10%，但最大拉伸应变和表观密度有所下降.

Abstract:

The ultra high toughness fly ash based geopolymer(FA EGC) was designed and prepared from fly ash as the main raw material. The effects of different curing ages, pre tensile strains and reaction temperatures on the compressive strength, apparent density, tensile properties and micro crack characteristics of FA EGC were studied. The results show that when water fly ash ratio is 035, the modulus of sodium silicate is 15， the content of sodium silicate is 6%(in terms of Na2O mass) and the volume fraction of PVA fibers is 1%, the specimen can produce obvious strain hardening characteristics, and its maximum tensile strain is up to 47%. With the increase of curing age, tensile strength of FA EGC specimen increases, but curing age has adverse effect on tensile strain. At the same pre tensile strain, total number of cracks will increase and average crack width will decrease with the increase of curing age in FA EGC specimens. At the same curing age, total number of cracks and average crack width of FA EGC specimens will increase with the increase of tensile strain. After high temperature treated, compressive strength, initial cracking strength and tensile strength of FA EGC specimens will increase by 6%, 60% and 10%, respectively, but maximum tensile strain and apparent density will decrease.