DEGRADATION OF CONCRETE SUBJECTED TO SIMULTANEOUS ATTACK OF FREEZE-THAW AND SUSTAINED FLEXURAL LOAD
In this paper a new method is proposed to assess the degree of degradation of concretesubjected to the simultaneous action of several deterioration factors. In the method, acoefficient (the damage index) is defined by which all deteriorations involved can be takeninto account. The deterioration of concrete under the simultaneous attack of freeze-thawcycling and sustained external flexural load is experimentally tested and then the thedegradation of the concrete under this complex deterioration is analysed using the newmethod. In the experiment, relative dynamic modulus of elasticity and mass loss are measured.The experimental results show that the drop in relative dynamic modulus of elasticity of theconcrete specimens dominants the failure of concrete whilst the mass loss mainly causes aconsiderable degradation at the initial stage. In the curve of the damage index correspondingto the concrete tested, the contribution of mass loss and the drop in relative dynamic modulusof elasticity to the degradation of concrete are clearly reflected with an obvious increaseduring the initial stage, followed by a slow increasing period and then finally a sharp increasein damage index. Also it is observed that the mass loss is not sensitive to external load. Thecriterion for mass loss suggested in the standards is quite easy to be satisfied and a morerigorous criterion should be proposed. For multi-factor attack, the interaction between therelevant factors plays an important role, which leads to the acceleration of the deterioration ofconcrete.
Ru Mu Wei Sun Changwen Miao J.P.Forth
School of Civil Engineering,University of Leeds,United Kingdom Jiangsu Academy of Building Science, College of Materials Science and Engineering,Southeast University,P.R.China Jiangsu Academy of Building Science,P.R.China School of Civil Engineering,University of Leeds,United Kingdom
国际会议
南京
英文
593-600
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）