根据预应力混凝土叠合受弯构件受力机理提出了考虑施工阶段与使用阶段两阶段受力的先张法预应力混凝土叠合梁使用阶段钢筋应力计算方法,填补了我国现行规范空白,并修正了规范中预应力混凝土叠合梁使用阶段裂缝宽度计算方法.参考美国 ACI 318 规范通过名义拉应力控制预应力构件裂缝的有关规定,基于具体工程提出了我国规范体系下先张法预应力混凝土 T 形叠合梁针对不同裂缝限值的名义拉应力控制建议值.
Research on Crack Calculation Method of Pretensioning Prestressed Concrete Composite Beams
According to the stress principle of prestressed concrete composite flexural members,the paper put forward the calculation method of the steel stress about pretensioned prestressed concrete composite beams in service stage,which takes into account the two stages of stress in construction stage and service stage,filling the gap in the current standard in China.The paper also revised the calculation method of crack width in the service stage about prestressed concrete composite beams in the code.Referring to the relevant provisions of American ACI 318 Code on controlling the cracks of prestressed components through nominal tensile stress,based on specific projects,the recommended nominal tensile stress control values for different crack limits of pretensioned prestressed concrete T-shaped composite beams under the Chinese code system were proposed.