Mechanical properties of prestressing steel at elevated temperature and after cooling

Abstract

The mechanical properties of prestressing steel at elevated temperatures and after cooling are essential to the fire resistance design and post-fire evaluation of residual load-carrying capacity of prestressed concrete structures. Although previous tests have provided useful results of mechanical properties of prestressing steel at elevated temperatures, the data obtained are somewhat scattered and still insufficient. Furthermore, few empirical formulas fitting the deterioration of prestressing steel at elevated temperatures and after cooling can be found.

This study therefore aims to extend the existing database with reliable data obtained by an accurate testing system. The study focuses on the mechanical properties of prestressing steel at elevated temperatures and after cooling by employing the central core wire of prestressing strand. Grade 1860 strands to GB/T5224 mostly used in Mainland China and Grade 1860 strands to BS5896 used in European countries are tested. The results are obtained using the steady-state method and compared with those from available literature and design standards.