BOND STRENGTH OF SELF-COMPACTING REINFORCED CONCRETE BEAMS EXPOSED TO SALINE WATER

Abstract

This study includes a series of bond tests related to reinforced concrete beams with rectangular cross section (140x150) & span of 600 mm that are provided with shear reinforcement. The specimens are tested as simply supported beams with one point load with strain reading in steel bar by strain indicator placed in a hole (recess) prepared for this purpose. Displacement between the steel bar and the concrete at the free end of bar has been measured. Three groups of beams have been tested to study the effect of many variables on bond strength for Self Compacting Concrete (SCC ) and conventional reinforced concrete (CC). The variables are: [steel bar diameter (8, 12 and 16) mm, concrete compressive strength (30, 60) MPa and type of curing (tap water continuous curing, saline water wetting and drying, saline water continuous exposing) for a time of (90 days). The study also involves the effect of each variable on bond strength and comparison between the results of all the specimens of SCC and CC bond stress-slip relationships. The results of comparison between all specimens of SCC and CC bond stress-slip relationships show that, the CC bond strength is lower than the SCC bond strength in two cases of curing (tap water continuous, saline water continuous exposing), but in case of saline water wetting and drying, the CC bond strength is higher than SCC bond strength.