缓粘结预应力混凝土T梁预应力效应分析

Prestressing Effect Analysis of Retard-bonded Prestressed Concrete T-beams

进行了2根预应力混凝土T梁的长期试验,通过对2种不同预应力施工工艺的混凝土梁在预应力施加后21 d的观测,研究了混凝土梁的跨中应变、预应力损失、挠度等方面的内容并进行了对比,在叠加法的基础上提出了计算存梁期间预应力混凝土简支梁挠度的理论方法.试验结果表明,缓粘结预应力梁与普通预应力梁的实测应变、挠度值发展规律基本相同.通过计算值与理论值的分析比较,验证了本试验理论计算的可靠性和精度,表明缓粘结预应力梁在存梁期有着与普通预应力混凝土梁相同的预应力效应.

To investigate the development laws of strain, prestress loss, and deflection of prestressed concrete beams under sustained load, long-term tests lasted 21 days on two prestressed concrete T-beams constructed by different construction technology were carried out. The calculation method of additional deflection in storage stage was proposed. The result of long-term tests shows that, the beam constructed by conventional technology and the new techniques of retard-bonded prestressed have similar development laws of strain and deflection. Comparing the calculated value with the theoretical value, the reliability and accuracy of the calculation method proposed here is verified. It shows that retard-bonded prestressed beams have similar prestressing effect with conventional prestressed concrete beams in storage stage.