负载钢筋混凝土梁钢筋锈蚀及使用性能试验研究

通过对负载下锈蚀、不负载锈蚀梁和一组参考梁的对比试验，研究了荷载对钢筋混凝土结构中钢筋锈蚀及钢筋混凝土梁变形性能和剩余承载力的影响．整个锈蚀试验过程中施加的持续荷载为极限荷载的0％、25％、45％和65％．通过交替喷洒3．5％的盐水来模拟海洋潮汐环境．采用外加电流来加速钢筋锈蚀．整个试验过程中检测梁的挠度，达到预定的时间后进行剩余承载力试验．结果表明，荷载对钢筋锈蚀有明显影响，荷载作用使梁锈蚀加速，梁的挠度增大，剩余承载力减小．由于钢筋混凝土结构一般都是负载工作的，所以对钢筋混凝土结构使用寿命进行预测时，应考虑使用荷载和暴露环境对结构耐久性能的影响．

Experimental studies on steel bar corrosion and serviceability of reinforced concrete beam under service loading

Based on testing of corroded reinforced concrete beams with or without sustaine d loading and comparison with a series of control beams, the effects of mechan ical loading on corrosion of reinforcing steel, the flexural deflection and resi dual loading capacity of reinforced concrete beams are studied. Beam specimens w ere subjected to sustained loading respectively corresponding to 0%, 25%, 45%, 65% of the ultimate load during the corrosion test process. The marine tidal e nvironment was simulated by alternately spraying and draining of 3.5% NaCl acqueous solution. An external direct current technique was used to acce lerate corrosion of the reinforcement. Beam deflections were recorded during the test process. The experiment of residual flexural loading capacity of the beams was carried out after the preset time. The results indicate that loading has a significant effect on corrosion. The corrosion rate is accelerated under sustai ned loading. With sustained loading the time dependent deflection of the beams increase and the residual loading capacity decrease. The reinforced concrete st ructures are usually subjected to loading. Therefore in service life predictio n of reinforced concrete structures, the influence of the service load and envi ronmental condition should be taken into account.