摘要
冲击韧性是表征材料在冲击类强载荷作用下材料抵抗变形和断裂的能力,是体现材料动特性的重要指标。针对课题组开发的环保型延性尾矿砂纤维增强水泥基复合材料DFTCC,采用落锤冲击圆板法和扫描电子显微镜试验,测试了DFTCC的冲击韧性和冲击破坏的微观特性,通过宏观与微观相结合的方式研究了DFTCC的抗冲击破坏机理及配合比关键参数的影响。研究表明,DFTCC具有较好的抗冲击韧性,其试样冲击破坏分为两个阶段,冲击破坏具有典型的塑性破坏特征。PVA纤维掺量和水胶比对于对于DFTCC的抗冲击性能影响显著,在适当范围内增加纤维掺量和水胶比可以在一定程度上改善DFTCC的抗冲击韧性。PVA纤维在DFTCC内部分布均衡,与水泥基体黏结良好,最终呈现纤维拉出和纤维断裂两种破坏形态。为绿色DFTCC动态机械性能的确定和工程应用,提供了参考。
The impacting toughness is the ability of characterization of materials to resist deformation and fracture under strong loadings,which is an important indicator to reflect the dynamic characteristics of the materials,including DFTCC,developed in the task which is one type.In order to study DFTCC,apply the test of the dropping hammer impacting disks and scanning electron microscopy.Eventually,the microscopic characteristic of impacting toughness and damage is drawn,as well as the influence of the failure mechanism and key parameters of the mixture ratio through the combination of macro and micro studying.It has shown that DFTCC has a good resistance to impact toughness,the impacting damage of the sample needs two stages and the plastic characteristics are highly typical.Study also indicates that dosage of PVA fiber and water-binder ratio affects resistance of DFTCC significantly,furthermore,increasing the content and ratio can improve impacting toughness in the appropriate range finally.If PVA fiber distributes in the internal balance and bonds with the cement matrix in high quality,the two fibers pulled out and fiber parted can be caused,which provide references about determining the dynamic mechanical properties and engineering applications of Green DFTCC.
出处
《混凝土》
CAS
北大核心
2016年第9期64-68,共5页
Concrete
基金
国家自然科学基金资助项目(51279109)
关键词
水泥基复合材料
尾矿砂
冲击韧性
微观分析
cementitious composites
tailings sand
impact toughness
microscopic analysis
