摘要:根据正负弯矩进行梁的正截面配筋设计时，由于不知道可能存在的可用于受压钢筋的配筋面积，梁的顶部和底部纵筋的计算一般由正负弯矩的最不利效应决定，不考虑由于构造或计算可能存在的受压钢筋的影响。根据本文的分析，在配筋率较大的情况下，如果不考虑受压钢筋的有利影响，将会造成材料浪费。本文提出了一种在不能确定受压钢筋面积时，通过简单的内力比较后，合理地考虑梁的受压钢筋的配筋设计方案。由本文的分析可以得出结论，这种配筋设计方案的设计结果确实可以达到节省材料的目的。

Abstract: When reinforcing bars for concrete beam according to positive and negative moments, generally, the top and bottom longitudinal reinforcement are determined only by the most adverse effects of the positive and negative moments and the influence of compressive reinforcement is ignored in this calculation, because of not knowing the area of reinforcement which may be used as compressive bar. According to the analysis of this paper, when the reinforcement ratio is high, if not considering the beneficial effects of compressive reinforcement, the waste of materials will be caused. This paper presents a reinforcement design method which can reasonably consider the influence of compressive bar by simple comparison of moments, when not knowing the area of compressive reinforcement. This analysis can concluded that the results by the method in the paper can really achieve the purpose of saving material.