Effect of alkali treatment of Jute fibers on the compressive strength of normal-strength concrete members strengthened with JFRP composites

The main objective of this experimental study is to evaluate the behavior of concrete members strengthened with Jute fibers reinforced polymer (JFRP). The fibers treated in an alkaline treatment of 4% of the NaOH solution during 24, and 48 hours using 10:1, and 15:1 of liquor ratios. Sixteen samples of concrete reinforced by JFRP are subjected to a compression test. The main issues investigated are the ultimate load, load-displacement behavior, failure modes and the effect of treatment on fiber and composites morphology. The results indicated that for the specimens reinforced by fibers treated during 24h in 10:1 liquor ratio have shown an increase of ultimate load capacity comparing to untreated and unreinforced specimens. However, for specimens treated for 48 h in 10:1 liquor ratio, a relatively slight increase in the ultimate load was observed. On the other hand, a slight degradation was witnessed in the specimens treated in 15:1 liquor ratio for both cases 24h and 48h treatment, respectively. A reduced number of cracks and failures appeared on the treated specimens comparing to untreated ones.