A study of the influence of environmental effects on the behaviour of a pre-stressed concrete viaduct

R. W. Howells, Cardiff School of Engineering, Cardiff University, UK
R. J. Lark, Cardiff School of Engineering, Cardiff University, UK
B. I. G. Barr, Cardiff School of Engineering, Cardiff University, UK

This paper addresses the influence that changing environmental effects have on the strains developed in a major pre-stressed concrete viaduct. The changes in strain, resulting from variations in temperature and relative humidity, were analysed over a period of one year. It was found that changes in temperature had a greater influence on the strain behaviour of the structure than changes in relative humidity, with strain variations of up to 75 microstrain (με) being recorded. A further study was conducted on the effect that changing temperature has on the strain behaviour of the viaduct during each of the four seasons. It was observed that the variation of temperature over the course of a week resulted in strains of up to 15 με. Finally, in both studies, a linear relationship was observed between strain and temperature, although these relationships differ slightly depending on the season, and the segment location within the span.