基于不同意义断裂韧度的混凝土有效裂缝扩展量计算模型  

Calculation model based on different fracture toughnesses for effective crack propagation of concrete

作　　者：王学志[1] 黄志强[2] 董锦坤[1] 刘钧玉[2] 朱朝艳[1] 

机构地区：[1]辽宁工业大学土木建筑学院,辽宁锦州121001 [2]沈阳工业大学建筑工程学院,辽宁沈阳110024

出　　处：《混凝土》2010年第7期15-18,21,共5页Concrete

基　　金：国家自然科学基金资助项目(50709013);辽宁省博士启动基金(20071025);辽宁省教育厅项目(20080318);辽宁省教育厅科学技术研究项目(2006B052)

摘　　要：针对混凝土有效裂缝扩展量存在尺寸效应的问题,结合名义断裂韧度和失稳断裂韧度尺寸效应公式对混凝土有效裂缝扩展量计算模型做了研究,得到了反映尺寸效应规律的有效裂缝扩展量的计算模型。通过对已有常态混凝土和课题组所做的碾压混凝土试验资料的分析,得到了两个模型对于混凝土的有效裂缝扩展量计算值。与试验结果进行对比分析,结果表明对于常态混凝土,含名义断裂韧度的模型适用于单直线软化模型,含失稳断裂韧度的模型较较适用于抛物线模型;而对于碾压混凝土,尺寸增大时接近单直线模型,且用名义断裂韧度模型计算更为接近。Aiming at size effect rule of concrete effective crack propagation,calculation models for concrete effective crack propagation were investigated with size effect formulae of nominal fracture toughness and unstable fracture toughness,and calculation models to reflect size effect rule for effective crack propagation were obtained.Using the two models to analyze existed common concrete test results and our roller compacted concrete test results,calculation values of concrete effective crack propagation based on the two models were gotten.By comparing calculation values and test results,some conclusions are gotten that the model with nominal fracture toughness is suitable for single line soften model and the model with unstable fracture toughness is suitable for parabolic curve soften model for common concrete;for roller compacted concrete,the model with nominal fracture toughness is suitable for single line soften model.

关 键 词：混凝土 有效裂缝扩展量 尺寸效应 断裂韧度 软化模型 

分 类 号：TU528.01[建筑科学—建筑技术科学]