Long-term flexural performance of concrete beams with different pozzolanic materials: experimental and analytical study

ABSTRACT

In this paper, a set of concrete beams with different cementitious binders are designed and tested to investigate the time-dependent deflection of concrete beams subjected to flexural load over a period of 1 year. Test parameters mainly included the effect of cementitious binders (silica fume (SF), ground-granulated blast-furnace slag (GGBS), and a combination of SF and GGBS), and polypropylene fibers on the time-dependent deflection of concrete. The specimens used in this study are under drying/unsealed conditions. The drying condition was designed to obtain the combination of the creep and the shrinkage that occurred in the common practice of construction. One of the most important problems in the repair of flexural members of concrete structures is the problem of creep and shrinkage, which is a relatively unknown problem in the literature. Furthermore, the experimental results are selected to validate the proposed models. Prediction of time-dependent deflections under flexural loading is proposed by the inverse analysis (IA) method. Based on the results, in comparison to the control specimen, the long-term deflection increases of 5.9% and decreases of 22.1% and 43.2% for specimens containing GGBS, SF and a combination of SF and GGBS, respectively, at the test age of 383 days.

KEYWORDS:

• Long-term deformation
• time-dependent behavior
• silica fume
• GGBS
• polypropylene
• creep

Acknowledgments

This is gratefully acknowledged that this study has been conducted in the Construction Materials Institute (CMI) at the University of Tehran, Iran. The authors would also like to acknowledge the support which has made this institute and this research possible.

Disclosure statement

No potential conflict of interest was reported by the author(s).