盐冻融-荷载耦合作用下高性能混凝土试验及损伤模型研究  

Experimental study and predicted model of high-performance concrete under combined actions of salt freezing-thawing and load

作　　者：田俊[1,2] 王文炜[1] 

机构地区：[1]东南大学交通学院,江苏南京210096 [2]青岛理工大学土木工程学院,山东青岛266033

出　　处：《混凝土》2015年第4期60-64,共5页Concrete

基　　金：国家自然科学基金资助项目(51078079)

摘　　要：通过对掺加粉煤灰、硅粉及矿渣的高性能混凝土在盐冻融-荷载耦合作用下的试验研究,提出了考虑多因素作用下混凝土疲劳损伤度模型。试验结果表明:荷载显著的影响盐冻融循环次数和破坏形态;不同应力状态下混凝土试件的质量变化率无明显差别。质量损失率是反映盐冻融-荷载耦合循环次数的主要参数,而相对动弹性模量是反映荷载影响的主要参数。提出的盐冻融-荷载耦合作用下的混凝土损伤度模型,可以反映出混凝土所受应力、相对动弹性模量、混凝土抗拉强度及循环次数对损伤度的影响。当耦合影响因子β接近零时,混凝土趋近疲劳寿命;所预测的损伤特性与实际损伤情况符合较好。Experimental works of high performance concrete mixed with fly ash,silica fume and slag,under combined actions of salt freezing-thawing and external load were conducted. The damage model was proposed to predict the fatigue degree of high performance concrete taking account on the effects of multiple factors. The test results showthat the external load has the significant influence on the repeated cycles of salt freeze-thawand failure mode. There are no obvious differences in the mass loss rate of specimens with different initial stress. The mass loss rate is an important parameter affected the numbers of salt-freeze thaw-load cycles; while the relative dynamic elastic modulus can be acted as another parameter to reflect the impact of external load on the durability. The proposed model for the high performance concrete indicates that the concrete approaches to fatigue life when the coupling impact factor β is close to zero.The predicted results are in good agreement with the experimental ones.

关 键 词：高性能混凝土 盐冻融-荷载耦合 质量损失率 相对动弹性模量 损伤模型 

分 类 号：TU528.01[建筑科学—建筑技术科学]