不同配筋形式超高性能混凝土梁受弯性能试验研究

Experimental Study on Flexural Behavior of Ultra-high Performance Concrete Beams with Different Reinforcement Forms

对3根不同配筋形式(普通钢筋配筋方案、钢板配筋方案、预应力筋配筋方案)的UHPC梁进行了受弯性能试验,结果表明:①相同配筋率条件下,钢板配筋方案(TB-2)较普通钢筋配筋方案(TB-1)更有利于限制裂缝的扩展,但对初裂荷载影响不大;②预应力筋配筋方案梁(TB-3)普通钢筋配筋率低,梁体开裂过后,裂缝迅速扩展,达到极限荷载时的最大裂缝远大于钢板配筋方案(TB-2)和普通钢筋配筋方案(TB-1);③建立了考虑受拉区UHPC抗拉贡献的抗弯承载能力计算公式,计算值与试验值吻合良好,为超高性能混凝土结构设计提供参考。

In this paper,the UHPC beams with three various reinforcement forms(scheme of common reinforcement,scheme of steel plate,and scheme of prestressed reinforcement)are tested for bending performance.The results indicated that:(1)With the same ratio of reinforcement in UHPC beams,the reinforcement scheme of steel plate(TB-2)is more conducive than the reinforcement scheme of common steel(TB-1)to limit the expansion of cracks,but it has little change in the first cracking load;(2)The reinforcement scheme of prestressed reinforcement beam(TB-3)is equipped with few ordinary steel bars.As a result,the cracks expand rapidly and the stiffness decreases rapidly after the beam body cracks and the maximum crack when the ultimate load is reached in the test is much larger than the reinforcement scheme of steel plate(TB-2)and reinforcement scheme of common reinforcement(TB-1);(3)Considering the contribution of UHPC′s tensile stress,the calculation formula of the flexural bearing capacity is established,and the calculated values agree well with the experimental values.The formula provides guidance for the designs of UHPC structure.