CONCRETE DETERIORATION MECHANISMS UNDER SIMULTANEOUS SULFATE ATTACK AND LOAD ACTION
The deterioration mechanisms of sulfate attack of concrete under sustained loading and wet-dry cycling are investigated based upon micro-and macroobservations. The sulfate-ion concentration in the sodium sulfate test solution was 50000mg/L with the corresponding mass fraction being 6.9％. Three loading levels of 20％, 40％ and 60％ of ultimate flexural load were investigated and the load was mechanically applied to the specimens under four-point bending. Micro-observation was the determination of the sulfate-ion content profile using the modified barium sulfate gravimetric method (chemical titration method). Macro-observation was the measurement of the flexural strength change. Test results showed: the tensile stresses can increase diffusivity by initiating or developing microcracks; the compressive stresses are small compared with the concrete compressive strength, so the any effect on ion transport properties are not observed; under simultaneous sulfate attack and flexural loading, deterioration is aggravated as the loading level increases, and this is characterized on the macroscale by increased strength degradation.
concrete sulfate load level strength degradation sulfate-ion content
Run-Dong Gao Shun-Bo Zhao Qing-Bin Li
State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, P.R. Chin School of Civil Engineering and Communication, North China University of Water Conservancy and Elect
国际会议
广州
英文
1160-1165
2009-11-28（万方平台首次上网日期，不代表论文的发表时间）