摘要
地聚物是一种有望替代普通硅酸盐水泥以降低土木工程行业碳排放的新型绿色环保胶凝材料。然而,粉煤灰-矿渣地聚物存在流动性差、干燥收缩大等问题,限制了其在工程领域的进一步推广应用。因此,通过试验研究了复掺减水剂和溶胶型纳米SiO_(2)对粉煤灰-矿渣地聚物工作性能、干燥收缩和抗压强度的影响,并分析了相关机理。试验结果表明,对于粉煤灰-矿渣质量比为7∶3的体系,与未掺加溶胶型纳米SiO_(2)和减水剂的粉煤灰-矿渣地聚物相比,当溶胶型纳米SiO_(2)和减水剂掺量分别为0.2%和1.0%时,粉煤灰-矿渣地聚物流动度从176 mm增大至198 mm,27 d干燥收缩降低了31.2%,3、7、28 d抗压强度分别提高了52.2%、24.5%、32.3%;溶胶型纳米SiO_(2)和减水剂复掺增加了参与反应的活性硅源,形成了更多的N-A-S-H和C-(A)-S-H凝胶产物,使得硬化后材料的结构更加致密。该研究可为粉煤灰-矿渣地聚物的进一步研究和应用提供参考。
Geopolymer is a new type of green cementitious material which is expected to replace ordinary Portland cement to reduce carbon emissions in civil engineering industry.However,the poor fluidity and large drying shrinkage of fly ash-slag geopolymer restrict its further application in the engineering field.Therefore,the effects of compound plasticizer and sol-type nano-SiO_(2) on the working performance,drying shrinkage and compressive strength of fly ash-slag geopolymer were studied through experiments,and the related mechanisms were analyzed.The experimental results show that as for the system with the mass ratio of fly ash-slag of 7∶3,compared with the fly ash-slag geopolymer without sol-type nano-SiO_(2) and plasticizer,the fluidity increases from 176 mm to 198 mm,the drying shrinkage at 27 d decreases by 31.2%,and the compressive strength at 3,7,28 d increases by 52.2%,24.5%and 32.3%,respectively when the content of sol-type nano-SiO_(2) and plasticizer is 0.2%and 1.0%,respectively;The addition of sol-type nano-SiO_(2) and plasticizer increased the active silicon source involved in the reaction and formed more N-A-S-H and C-(A)-S-H gel products,which made the structure of the hardened material more compact.This study can provide reference for the further research and application of fly ash-slag geopolymer.
作者
李新宇
彭金财
段立伟
王武
李伟宇
许福
Li Xinyu;Peng Jincai;Duan Liwei;Wang Wu;Li Weiyu;Xu Fu(Hunan Xihu Construction Group Co.,Ltd.,Changsha 410000,China;College of Civil Engineering,Xiangtan University,Xiangtan 411105,China;Yueyang Road and Bridge Group Co.,Ltd.,Yueyang 414000,China)
出处
《市政技术》
2024年第2期21-26,114,共7页
Journal of Municipal Technology
基金
国家自然科学基金项目(52078122)
湖南省住建厅建设科技计划项目(KY202314、KY202316)。
