Polyvinyl Alcohol (PVA) fiber was developed more than 80 years ago in Japan. They are heavily used in nonstructural
applications and in Engineered Cementitious Composites (ECC) mainly for beams and thin slabs
sections. There are gaps in the research regarding their performance in other structural elements and at elevated
temperatures. The aim of this work is to study the behavior of reinforced concrete columns containing PVA fibers
after being subjected to elevated temperatures and then loaded either concentrically or eccentrically. A total of
thirty-six reinforced concrete columns, having constant longitudinal reinforcement, were experimentally tested
under different load eccentricity ratios (0.0, 0.50, and 1.0). Different ratios of PVA, 0.75%, 1.50%, 2.25% were
included in the concrete mixes. The studied columns were exposed to elevated temperature before loading. It
was observed that columns containing PVA fibers had higher ultimate loads, higher ultimate deflection, less
crack widths, higher ultimate deflection, higher energy absorption, and higher temperature resistance compared
to normal reinforced concrete columns. In addition, these columns didn’t show any sign of spalling due to the
fiber bridging effect of PVA fibers unlike other studied normal reinforced concrete columns without fibers. It was
found that addition of 1.50% fiber content showed better performance for centrically loaded columns while this
was raised to be 2.25% for eccentrically loaded columns. The ultimate load of the columns exposed to elevated
temperature rapidly decreased with increasing the duration of temperature to different magnitudes depending
on the percentage inclusion of PVA fibers. It was found that ductility and energy absorption for columns including
1.5% PVA were higher than their companions without fibers after temperature exposure. It was observed
that the energy absorption of eccentric columns exposed to temperature for up to two hours was still higher than
that of their companions without fibers by 40% for eccentricity ratio of 1.0. |
