长江科学院院报 ›› 2019, Vol. 36 ›› Issue (2): 139-143.DOI: 10.11988/ckyyb.20170811

• 水工结构与材料 • 上一篇    下一篇

龄期对碾压混凝土双K断裂参数影响的试验研究

李根1,2,王学志1,张晓飞3,陈意勤4,胡柯心1,李春蕊1   

  1. 1.辽宁工业大学 土木建筑工程学院,辽宁 锦州 121000;
    2.天津市赛达伟业有限公司,天津 300000;
    3.西安理工大学 水利水电学院,西安 710048;
    4.潍坊市公路路桥工程建设开发中心,山东 潍坊 261061
  • 收稿日期:2017-07-19 修回日期:2017-07-27 出版日期:2019-02-01 发布日期:2019-03-11
  • 通讯作者: 王学志(1976-),男,辽宁锦州人,教授,博士,主要从事混凝土断裂研究。E-mail:myemailwxz@163.com
  • 作者简介:李 根(1993-),男,河北秦皇岛人,硕士研究生,主要从事混凝土断裂研究。E-mail:741059786@qq.com
  • 基金资助:
    国家自然科学基金面上项目(51479168);辽宁省自然科学基金项目(2015020214)

Influence of Age on Double-K Fracture Parameters of Roller Compacted Concrete

LI Gen1,2,WANG Xue-zhi1,ZHANG Xiao-fei3,CHEN Yi-qin4,HU Ke-xin1,LI Chun-rui1   

  1. 1.School of Civil and Architectural Engineering, Liaoning University of Technology, Jinzhou 121000, China;
    2.Saidaweiye Co., Ltd., Tianjin 300000, China;
    3.Institute of Water Resources and Hydro-electric Engineering, Xi’an University of Technology, Xi’an 710048, China;
    4.Construction and Development Centre of Road & Bridge Engineering of Weifang City, Weifang 261061, China
  • Received:2017-07-19 Revised:2017-07-27 Online:2019-02-01 Published:2019-03-11

摘要: 为了研究龄期对碾压混凝土双K断裂参数的影响,制作了龄期为28,60,90 d共18个楔入劈拉碾压混凝土试件并进行了断裂试验,结合双K断裂参数公式,得到了不同龄期试件的有效裂缝长度、起裂断裂韧度和失稳断裂韧度等断裂参数,并分析了龄期对碾压混凝土断裂性能的影响。试验结果表明:起裂荷载和失稳荷载均随龄期的增大而增大,且起裂和失稳荷载的比值趋于稳定,伴随着龄期的增加,起裂荷载占失稳荷载的比重越来越大;龄期从28 d增加到90 d,起裂和失稳断裂韧度分别增加了0.216 0 MPa·m1/2和 0.292 2 MPa·m1/2,起裂和失稳断裂韧度的比值基本在0.5~0.6;有效裂纹长度随龄期的增大而减小,相同尺寸下,龄期越小,裂缝亚临界扩展量越大,试件的韧性越好。

关键词: 碾压混凝土, K断裂理论, 龄期, 楔入劈拉试验, 断裂韧度

Abstract: The influence of age on Double-K fracture parameters of roller-compacted concrete (RCC) was investigated via fracture test on eighteen RCC wedge splitting specimens at different ages (28 d, 60 d, and 90 d). The effective crack length, initial fracture toughness and unstable fracture toughness of the RCC specimens of different ages were acquired. Results revealed that with the growth of age, the critical pressure for initial cracking and critical pressure for instability both expanded, and the ratio of critical pressure for initial cracking to critical pressure for instability also increased. With the age increasing from 28 d to 90 d, initial cracking toughness KiniIC and unstable cracking toughness KunIC climbed by 0.216 0 MPa·m1/2 and 0.292 2 MPa·m1/2, respectively; the ratio of KiniIC to KunIC maintained between 0.5 and 0.6 in general. Effective critical cracking length and subcritical crack extension both changed in a negative relation with age, implying that smaller age results in better toughness of specimens.

Key words: roller-compacted concrete, double-K fracture parameters, age, wedge splitting test, fracture toughness

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