摘要:
利用电迁移钢筋锈蚀法,通过中心拉拔试验对钢筋混凝土非均匀锈蚀试件的粘结性能进行研究。试验结果表明:在非均匀锈蚀条件下,试件的开裂不仅取决于锈蚀率,还与锈蚀面积比有关,相同条件下,锈蚀面积比越大,保护层胀裂所需的锈蚀率越小;锈胀裂缝对非均匀锈蚀无箍筋试件的粘结强度有明显影响,随裂缝的产生及发展,试件粘结强度急剧下降,而配箍试件则不然,即便是裂缝宽度达0.2 mm,极限粘结强度也不会下降;锈蚀率在2.4%以内,非均匀锈蚀对试件粘结滑移性能的影响并不十分显著。
Abstract:
Based on the electro -migration method for corrosion simulation, pull-out tests were conducted to study the bond properties of non -uniformly corroded deformed bar in concrete. The following conclusions can be drawn from this study; 1) The concrete cover-cracking is influenced not only by corrosion rate but also by area ratio of corroded bar in concrete. Under the same conditions, the larger the area ratio of corroded bar is, the smaller the corrosion rate of bar will be at the cover cracking time. 2) For member s wi thout stirrups, the bond strength will decrease at cover cracking. Then the larger the crack width is the less the bond strength will be. But for hooped members, the ultimate bond strength will not be weakened even the crack width is up to 0.2mm. 3) It is not remarkable that non-uniform corrosion influence on bond slip between concrete and deformed bar when the corrosion rate is within 2.4%