部分预应力轻骨料混凝土受弯构件的变形计算

CALCULATION FOR THE DEFLECTION OF PARTIALLY PRESTRESSED LIGHT CONCRETE BEAM

本文提出部分预应力轻骨料混凝土受弯构件在使用阶段的变形曲线符合双直线模式。并通过理论推导和试验分析给出了此类构件在两直线段内的短期刚度计算公式。文中对影响弹塑性分刚度B的因素进行了分析,提出B的表达式为B=cE_cI_0。给出了以折减系数D表示的总刚度计算公式。通过国内39根试验梁88个测点的验算表明,理论值与试验值符合较好。本公式具有物理概念明确、计算简便、且与近年国内的科研成果有较好的衔接等优点。

In this paper, a possible approach to the calculation of the deflection in partially prestressed lightconcrete beams (PPLCB) is presented. Based on the theoretical derivation, experimental analysis and as-sumption that the load-deflection curves of elements under service loads conform to a two-linemodel, a calculating formula for the short period rigidity of this kind of beams is proposed. A detailedstudy on the parameters which may influnce elastic-plastic rigidity is also presented. The paper leads tothe conclusion that the major factor controlling the deflection behavior of a PPLCB, apart from themodulous of elasticity and moment of inertia, is the converted ratio of reinforcement. Test results fromthirty-nine beams give a good agreenment with the data calculated according to this theory. This for-mula is explicit in concept and simple in calculation, and has a good correlation with the previous re-search achievements.