钢筋UHPC梁抗弯承载能力理论分析

Theoretical Analysis of Bending Capacity of Reinforcement UHPC Beams

根据受弯构件正截面承载力计算的原理,假定钢筋UHPC梁受弯时满足平截面假定、材料的本构关系为双折线、梁受拉区考虑部分抗拉强度,将受压区UHPC截面简化成矩形受力面和三角形受力面之和,将受拉区UHPC截面简化成矩形受力面,推导出钢筋UHPC梁在受弯时受压区的合力公式及合力的作用点公式,进而得出钢筋UHPC梁抗弯承载能力理论计算方法,利用该计算方法对已有的钢筋UHPC抗弯试验梁进行分析,并与试验得到的抗弯极限结果对比,结果表明,利用所推导的理论计算方法对钢筋UHPC抗弯承载能力的计算具有较高的精度,并利用推导公式对UHPC梁的配筋率和含纤维量对抗弯承载力进行分析,得出它们对抗弯承载力的影响。

According to the principle of calculation of the bearing capacity of the normal section of a flexural member,it is assumed that the reinforced UHPC beam meets the assumption of a flat section when bending,the material constitutive relationship is a double-fold line,and the tensile strength of the beam takes the partial tensile strength into account.The section is simplified into the sum of rectangular force surface and triangle force surface.The UHPC section in the tension zone is simplified into a rectangular force surface.The formula of the combined force and the point of action of the combined force in the compression zone of the reinforced UHPC beam during bending are derived.Furthermore,a theoretical calculation method for the flexural bearing existing reinforced UHPC beams is obtained.This calculation method is used to analyze the existing reinforced UHPC flexural test beams,and the results are compared with the obtained bending limit results.The results show that the deduced theoretical calculation method is the calculation of the UHPC flexural bearing capacity of steel bars has a high accuracy,and the derivation formula is used to analyze the reinforcement ratio and fiber content of the UHPC beam to resist the bending capacity,and the influence of their resistance to the bending capacity is obtained.