配置高强非预应力钢筋的预应力混凝土梁受弯试验研究

Bending Experimental Study on the Prestressed Concrete Beams with High-Strength Non-prestressed Steel Bars

通过对配置HRB600非预应力钢筋的预应力混凝土梁进行受弯试验,分析了混凝土及非预应力钢筋应变的发展规律,研究了预应力筋预应力损失的计算方法,提出了试验梁短期抗弯刚度的计算修正公式。研究结果表明:试验梁跨中截面平均应变符合平截面假定,HRB600钢筋的受力过程呈现显著的三阶段发展规律;计算预应力筋的预应力损失σ4和σ5时,引入时间影响系数可以有效提高准确性;通过引入综合配筋率影响系数,可以有效提升试验梁的短期刚度计算精度,配置HRB600非预应力钢筋的预应力混凝土梁在正常使用阶段满足挠度限值要求。

Through the bending experiment of the prestressed concrete beams with HRB600,the development laws of the concrete and the strain for the non-prestressed steel bars were analyzed,and the calculation methods of the prestress loss were studied and the rectification formula of bending stiffness were proposed.The results show:the average strain at mid-span section conform to the plane section assumption,and the loading process of HRB600 fell into three stages;Calculation accuracy of the prestress loss(σ 4 andσ 5)can be improved by introducing the influence coefficient of the time;Calculation accuracy of the tested beam’s short-term bending stiffness are improved by introducing the coefficient of the comprehensive steel ratio and the specimens during the period of normal use can meet the requirement of the maximum deflection.