摘要
将微米级的CaCO_(3)晶须加入钢-聚乙烯醇(PVA)纤维水泥砂浆中,通过三点弯曲切口梁试验,分别研究CaCO_(3)晶须掺量和水灰比对钢—PVA纤维增强水泥砂浆断裂性能的影响.试验表明,CaCO_(3)晶须可以改善钢—PVA纤维水泥砂浆的断裂性能,其中1%CaCO_(3)晶须的提高效果最为显著.随水灰比的增大,CaCO_(3)晶须改性钢—PVA纤维水泥砂浆的断裂性能逐渐降低.在水灰比较小时,CaCO_(3)晶须、PVA纤维以及钢纤维之间关于失稳断裂韧度和断裂能呈现正混杂效应,且正混杂效应对断裂能的作用更显著.此外,机理分析表明:CaCO_(3)晶须可以在微观尺度上对钢—PVA纤维增强水泥砂浆实现阻裂增强.
Micron-sized CaCO_(3) whiskers were added into steel-polyvinyl alcohol(PVA) fibers reinforced cement mortar.The influence of CaCO_(3) whiskers contents and water-cement ratio on fracture properties of steel—PVA reinforced cement mortar was studied by three-point bending testing of notched beams.The results showed that the presence of CaCO_(3) whiskers could improve the fracture properties of steel—PVA reinforced cement mortar, especially the addition of 1% CaCO_(3) whiskers.The fracture properties of CaCO_(3) whiskers modified steel—PVA fibers reinforced cement mortar gradually decrease with the increases of water-cement ratio.The positive hybrid effect of CaCO_(3) whiskers, PVA and steel fibers on unstable fracture toughness and fracture energy was observed with lower water-cement ratio, and the positive hybrid effect had more significant effect on the fracture energy than that of unstable fracture toughness.Moreover, mechanism analysis showed CaCO_(3) whisker could achieve the effect of crack resistance at micro-scale.
作者
谢超鹏
曹明莉
司雯
刘子兴
XIE Chaopeng;CAO Mingli;SI Wen;LIU Zixing(Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China)
出处
《应用基础与工程科学学报》
EI
CSCD
北大核心
2021年第4期1032-1043,共12页
Journal of Basic Science and Engineering
基金
国家自然科学基金项目(51678111,51478082)。
