【摘要】 对8根预应力高强混凝土和1根普通混凝土有腹筋T形截面简支梁的抗剪强度进行了试验研究。观察了有腹筋T形截面梁在不同参数变化下梁的斜向裂缝开裂特点和破坏形态;结合清华大学21根预应力高强混凝土(fcu=62.7~84.3MPa)无腹筋和有腹筋简支梁的试验研究,综合分析了混凝土强度、剪跨比、预应力度(预压比)、配箍率和纵筋配筋率对抗剪强度的影响及变化规律,通过对66根混凝土强度变化范围为fcu=25.5~84.3MPa的非预应力和预应力混凝土梁回归统计分析,提出了适合于上述混凝土强度范围内、在集中荷载作用下简支梁(T形或I字形截面)抗剪承载能力的建议公式。更多还原

【Abstract】 It is presented an experimental investigation on the shear capacity of eight simply supported and pre-stressed high-strength T-section concrete beams and one normal-strength concrete beam with web reinforcement.The diagonal cracking characteristics and the failure states of these beams under the condition of the different parameters are studied.The influences on the shear capacity of the concrete strength,pre-stress-to-compressive strength ratio,shear span-to-depth ratio,transverse tie ratio and longitudinal steel ratio are further analyzed statistically.On the base of this investigation and other investigations carried out before by Tsinghua University,it suggests a calculating formula of the shear capacity of these beams under the concentrated loading.The calculated results by this formula agree well with the experimental results.更多还原