GO-PVA注浆材料的制备及其强度特征研究

Preparation of GO-PVA grouting material and its strength characteristics study

由于瓦斯抽采钻孔周围稳定性较差,受扰动影响易致钻孔周围煤岩体产生新的裂隙,进而降低瓦斯抽采效率,为填补现有材料颗粒大、胶结能力差的缺陷,引入纳米材料和高分子聚合物材料改善瓦斯抽采钻孔封孔材料的性能,并分析纳米材料氧化石墨烯(Graphene Oxide,GO)、高分子聚合物聚乙烯醇(Polyvinyl Alcohol,PVA)纤维复掺于水泥基注浆材料中的宏微观强度特征。采用单因素试验探究GO最佳质量分数及PVA纤维最佳长度和质量分数,确定最优值后再与普通水泥注浆材料进行复合对比试验,并通过单轴压缩测试不同养护龄期下的强度变化规律,结合蠕变特性、相似模拟和扫描电子显微镜(Scanning Electron Microscope,SEM)图像,探讨复合材料的增强机理。研究结果表明:两类添加剂均对水泥基注浆材料抗压强度展现出有效的提升作用,尤其是当氧化石墨的质量分数为0.04%,PVA质量分数和长度分别为0.2%和3 mm时,其抗压性能达到顶峰,密封性能提升,抵抗外界应力变化的能力得到增强。研究结果可为封孔注浆材料的研发提供基础。

In order to address the shortcomings of current materials with large particles and inadequate cementing properties,and to enhance the sealing efficacy,we examined the macroscopic and microscopic strength attributes of industrial-grade Graphene Oxide(GO) nanoparticles and polymer Polyvinyl Alcohol(PVA) fibers when incorporated into cement-based grouting materials.The optimal optimum mass fraction of GO and the ideal length and mass fraction of PVA fiber were analyzed individually to determine the best combination before conducting a comparative test with standard cement grouting materials.We conducted uniaxial compression tests to study the strength evolution of composites under varying curing durations.Additionally,we examined the creep properties and utilized similar simulations and Scanning Electron Microscope(SEM) images to delve into the reinforcement mechanism of the composites.Our findings indicate that both additives effectively enhance the compressive strength of cementitious grouting materials,with optimal performance achieved when the Graphene Oxide(GO) mass fraction 0.04%.Furthermore,it was noted that the compressive strength of PVA fibers exhibited significant improvement compared to the control group,irrespective of the fiber length,at spiking ratios ranging from 0.1% to 0.3%.Notably,the most pronounced effect was observed with 3 mm fibers,resulting in a 44.38% enhancement.Simultaneously,the addition of GO and PVA fibers in appropriate proportions can optimize the pore structure of cementitious grouting materials,facilitate the formation of hydration products,leading to a denser structure,and ultimately reduce internal material defects.Through enhancing the bonding force with the cement matrix,the incorporation of nanomaterials and polymer fibers resulted in improved macroscopic mechanical strength of the specimens.Graded creep loading confirmed the uniaxial compressive strength of the composite cementitious materials,demonstrating their ability to effectively withstand external stress variations,enhance sealing performance,and prolong the lifespan of sealing holes.The findings from this study serve as a foundation for further research and development of grouting materials for hole sealing applications.