预应力筋受力不均匀性试验分析

Analysis of Tests on the Tensile Stress Unevenness of Prestressing Tendons

对预应力筋受力不均匀性,采用在每根预应力筋上对称粘贴两应变片,分别以单根张拉和4根同时张拉的试验方法进行分析.试验是在标定的数值下按不同的步骤,利用锁定力来测实预应力筋,结果表明:单根张拉时,第1根预应力筋和其他3根预应力筋的受力均不同.而4根同时张拉时,从一开始各根预应力筋受力就不均匀.

With two foil gauges stuck on each prestressing tendon, discussion is made about the tensile stress unevenness of prestressing tendons on two tests of one-by-one-tendon stretch and 4-tendon simultaneous stretch individually. Under the rating numerical values, the prestressing tendons, on the basis of different steps, are tested by means of the lock-up force. The result reveals that the tensile stress of the first tendon is different from that of each of the rest three tendons when single tendon is stretched, while the tensile stress of each tendon is uneven at the initial stage when 4 tendons are stretched simultaneously.