纳米SiO_(2)对玄武岩纤维增强煤矸石粉-矿粉基地质聚合物砂浆性能的影响  

Effects of nano-SiO_(2) on properties of basalt fiber-reinforced coal gangue-mineral powder-based polymer mortar

作　　者：张树祥 张天昊 张东生 杨秋宁[1] ZHANG Shuxiang;ZHANG Tianhao;ZHANG Dongsheng;YANG Qiuning(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China;Department of Civil Engineering,KU Leuven,Campus Bruges,Bruges 8200,Belgium)

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021 [2]Department of Civil Engineering,KU Leuven,Campus Bruges,Bruges 8200,Belgium

出　　处：《中国粉体技术》2024年第6期173-186,共14页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:51568055;宁夏回族自治区重点研发计划项目,编号:2021BEG02014。

摘　　要：【目的】为了改善煤矸石粉-矿粉基地质聚合物砂浆的脆性破坏特征,采用纳米SiO_(2)对玄武岩纤维增强煤矸石-矿粉基地质聚合物砂浆(basalt fiber-reinforced coal gangue-mineral powder-based geopolymer mortar,BGSG)进行改性。【方法】采用流动度、流变性、抗压强度、抗折强度、单轴拉伸和断裂试验并结合能量准则和微观手段研究纳米SiO_(2)增强地质聚合物砂浆的增韧机制。【结果】随着纳米SiO_(2)掺量的增加,BGSG的流动度逐渐下降,触变面积、屈服应力和塑性黏度逐渐增大;当纳米SiO_(2)掺量(质量分数)为3%时增韧效果最好,养护龄期为28 d时,纳米SiO_(2)改性BGSG的抗压强度为22.3 MPa,抗折强度为6.8MPa,极限拉伸强度为5.75 MPa,失稳韧度为0.534 MPa·m^(1/2),与未掺加纳米SiO_(2)的对照组相比,其抗压强度、抗折强度、极限拉伸强度和断裂失稳韧度分别增加29.1%、39.5%、36.9%、47.8%;微观分析表明,纳米SiO_(2)掺入并未改变地质聚合物水化产物的类型。【结论】纳米SiO_(2)参与聚合反应,促进地质聚合物凝胶的生成,从而增强BGSG的综合性能。Objective The approach for preparing a coal gangue-mineral powder-based geopolymer mortar using coal gangue powder and mineral powder as precursors,with water glass and NaOH as alkali activators,mitigates coal gangue accumulation and environmental pollution.However,coal gangue-mineral powder-based geopolymers have inherent defects such as high brittleness,low toughness,and susceptibility to cracking.To improve the fracture characteristics of this geopolymer mortar,nano-SiO_(2) is introduced to modify basalt fiber-reinforced coal gangue-mineral powder-based geopolymer mortar(BGSG).Methods The effects of nano-SiO_(2) on the fluidity,rheology,compressive strength,flexural strength,uniaxial tensile strength,and fracture performance of the geopolymer mortar were evaluated by adjusting the content of nano-SiO_(2).A control group without nano-SiO_(2) was used for comparison.The impact of different nano-SiO_(2) contents(1%,2%,3%)on the performance of the geopolymer mortar,primarily composed of coal gangue powder and mineral powder,was investigated.The mechanisms by which nano-SiO_(2) affected the geopolymer mortar properties were explored using energy criteria,X-ray diffraction,infrared spectroscopy,and thermogravimetric analysis.Results and Discussion With the increase in nano-SiO_(2) content,the fluidity of BGSG decreased.When the nano-SiO_(2) content reached 3%,the fluidity of the geopolymer was 110 mm,which was 38.5% lower than that of the control group(179 mm).The thixotropic loop area of BGSG expanded with higher nano-SiO_(2) content.At nano-SiO_(2) contents of 1%,2%,and 3%,the loop areas were 3140,4080,and 5000 Pa/s,respectively,showing increases of 21.2%,57.5%,and 93.1% compared to the control group(2590 Pa/s).The yield stress and plastic viscosity of the slurry increased with higher nano-SiO_(2) content,with yield stress rising from 31.5 Pa to 72.7 Pa,and plastic viscosity from 6.95 Pa·s to 11.45 Pa·s.The optimal toughening effect was observed at a 3% nano-SiO_(2) content.After 28 days of curing,the compressiv

关 键 词：地质聚合物 煤矸石粉 纳米二氧化硅 流变性 增韧机制 

分 类 号：TB44[一般工业技术] TQ324.8[化学工程—合成树脂塑料工业]