Abstract
The method of analysis for long-term bendings have not been fully established in reinforced slabs under service loads. Even on instantaneous bendings, several problems for analysis on it have been remained unsolved partly though some methods for analysis which have effective work within relatively small deflection, several millimeters, have been proposed. The first reason of such a situation is that analytic treatments for slippage of tension steel at slab's edges is uncertain. The final purpose of this studies is to estabilish a method of analysis on long-term bendings in reinforced concrete slabs, and as a part of studies and the first part, analytic treatments for slip-page of tension steel is proposed, and an analytic method for instantaneous bendings considered slippage in one way slabs is shown. The validity for this analytic method is investigated with previously published test data. Furthermore, by utilized those analysed results, several examinations are carried out. The followed results is obtained. (1)γ〜s relation of bi-linear type proposed in this paper can be applied satisfactorily for the calculation of slippage of tension steel. (2) The analytic method in consideration of slippage of tension steel in this pater suitably estimates instantaneous deflections and re-arrangement of stresses after being cracked. (3) At least, the creation for allowable unit stress of tension steel for service loads has no effect for control of deflections or cracks on instantanous bendings of reinforced concrete slabs.
