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Na 2O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.
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.
作者
郭晓潞
熊归砚
GUO Xiaolu;XIONG Guiyan(Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education,Tongji University,Shanghai 201804,China;School of Materials Science and Engineering,Tongji University,Shanghai 201804,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2019年第6期949-956,共8页
Journal of Building Materials
基金
上海市自然科学基金资助项目(17ZR1442000)
中央高校基本科研业务费专项资金资助项目(22120180087)
关键词
超高韧性
应变硬化
裂纹总数
平均裂纹宽度
ultra-high toughness
strain hardening
total number of cracks
average crack width
