摘要: |
通过三点弯曲梁试验研究了聚丙烯纤维掺量和种类对抗压强度>100MPa的超高强混凝土断裂性能的影响.结果表明:超高强混凝土裂缝破坏过程分为3个阶段.聚丙烯纤维对延缓超高强混凝土第1阶段和第2阶段裂缝破坏发展有一定的效果,但效果不明显.聚丙烯纤维对延缓超高强混凝土第3阶段裂缝破坏发展效果明显.与未掺聚丙烯纤维超高强混凝土相比,掺2kg·m-3长度19mm聚丙烯纤维的超高强混凝土断裂能增加508%,韧性提高545%,各龄期抗压强度增大,而掺2kg·m-3长度9mm聚丙烯纤维的超高强混凝土断裂能增加455%,韧性提高294%,各龄期抗压强度降低. |
关键词: 聚丙烯纤维 断裂能 脆性 裂缝破坏发展 超高强混凝土 |
DOI:103969/j.issn1007 9629201503022 |
分类号: |
基金项目:“十二五”国家科技支撑计划项目(2011BAJ03B10);贵州省重大科技专项项目(黔科合重大专项字[2012]6024号) |
|
Effects of Polypropylene Fibres on Fracture Energy Properties of Ultra High Strength Concrete |
QI Guihai1, PENG Xiaoqin1, YE Haowen2, DONG Yi3
|
1.College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China;2.China Construction Fourth Engineering Division Corp. Ltd., Guangzhou 510665, China;3.Guizhou Construction Science Research and Design Institute Corp. Ltd. of CSCEC, Guiyang 550006, China
|
Abstract: |
The effect of polypropylene fibres(PP fibres) on fracture properties of ultra high strength concrete(UHSC), which has compressive strength of more than 100MPa, were studied by the method of three point bending beam test. The results show that the development of crack in UHSC can be defined in three stages, and PP fibres are more effective to prevent the development of crack in third stage than in first and second stages. Compared to the UHSC without PP fibres added, the fracture energy and toughness of UHSC with 2kg·m-3 PP fibres of length of 19mm added are increased by 508% and 545% respectively, the compressive strengths at different ages are also increased, and the fracture energy and toughness of UHSC with 2kg·m-3 PP fibres of length of 9mm added are increased by 455% and 294% respectively, but the compressive strengths at different ages are decreased. |
Key words: polypropylene fibre fracture energy brittleness crack failure and development ultra high strength concrete |