碳纤维-棱柱体预应力混凝土复合筋混凝土梁挠度的试验研究及计算方法

EXPERIMENTAL STUDY AND CALCULATION ON DEFLECTION OF THE NEW CFRP-PCPS CONCRETE BEAM

对7根自行研制的碳纤维-棱柱体预应力混凝土复合筋(CFRP-PCPs复合筋)混凝土梁进行了关于挠度的试验研究。对比发现:CFRP-PCPs复合筋混凝土梁在各受力阶段的挠度均较普通预应力CFRP筋混凝土梁小;CFRP-PCPs复合筋混凝土梁的挠度与CFRP的张拉控制应力及复合筋的截面面积有关,随着复合筋预应力和面积的增大,构件的挠度有一定程度的减小。在考虑CFRP-PCPs复合筋等效原理的基础上,对我国现行《混凝土结构设计规范》中适用于预应力钢筋混凝土梁的短期刚度计算公式进行修正,提出了适合新型CFRP-PCPs混凝土梁的挠度建议计算公式,并应用建议公式对其中含CFRP-PCPs复合筋的5根试验梁的挠度进行计算。将计算值与试验值对比,结果吻合良好。

Deflection tests of seven self-developed new CFRP -PCPs composite reinforced concrete beams were carried out .It was found by comparison that the deflection of CFRP -PCPs composite reinforced concrete beams of all the forced stages was smaller than ordinary prestress CFRP reinforced concrete beams .The deflection of the CFRP-PCPs composite reinforced concrete beams was related to the tension control stress and the cross -sectional area of the composite bar .With the increase of composite prestress and the area , the deflection of the members decreased to some extent .Based on the principle of equivalence of CFRP -PCPs composite reinforcement , the formula of short-term stiffness which suitable for prestressed reinforced concrete beams in “Code for Design of Concrete Structures”was revised.A suggested formula was put forward which applies to the new type concrete beams of CFRP -PCPs, and the proposed formula was used to compare the five test beams with CFRP-PCPs composite bar .The result shows that the calculated values were accordance well with the experimental values .