SERVICEABILITY ANALYSIS OF CONCRETE SECTIONS

With the publication of the draft version of the SAA unified code for concrete structures attention has been focussed on serviceability analysis for prestressed and reinforced concrete. As the NAASRA bridge design code will closely follow this approach, this paper will show how such analysis can be carried out, particularly for deflection calculations and control. In the age of the micro computer and programmable calculator, it is now possible to attack the problems of the effects of creep, shrinkage, load history, cracking and tension stiffening on deflection computations. It is also a simple matter to perform computations for stresses which result in large cost savings by reducing prestress requirements. This paper seeks to give a straightforward logical approach to beam deflection by refined computation and crack control in as will be required by the code. The methods apply to all concrete bridge decks, whether slabs, slabs and beams or box sections and whether reinforced or prestressed. The number of the covering abstract for the conference is TRIS NO. 393385. (Author/TRRL)