Padronização de vigas de betão pré-fabricado para tabuleiros de pontes rodoviárias

Abstract

Precasting in bridge decks, widely applied in the girders, has been presented as a convenient solution for helping, mainly, in accelerated bridge construction, higher quality of the elements, as well as the reduction of work traffic. Since for each project, there may be a new girder cross-section, this may imply in the investment in new formworks and relearning for production, making the process less competitive and time-consuming. In order to answer this question, standardization arises, which consists in the simplification of production, recurring on pre-conceived girder sections. Thus, in the present work, precast prestressed girders for road bridge decks were standardized, where the deck slabs are cast in place, and their design was carried out for spans of 10 to 30 meters, taking into consideration the loads from the Southern Africa Transport and Communications Commission (SATCC), applicable to the Southern African Development Community (SADC) region, in conjunction with extreme weather effects, according to recommendations existing in Mozambique. The design was made with CSiBridge design software, where girders’ internal forces were obtained for the applied loads, allowing subsequent verifications to be carried out. During the analysis, long-term effects on the deck slab were studied, namely creep and shrinkage, and the consequences due to the differential behaviour between the girders and the slab, due to these effects. Its design resulted in four sections, a rectangular girder section for spans from 10 up to 15 meters and three “I” girder sections for spans ranging from 16 to 30 meters, where their dimensions were determined so as to optimize formwork use and make their assembly easy at the destination. With the standardized sections, it contributes to a more accelerated construction, lower production costs and a greater incentive for the precast of bridge girders