Bond strength of coconut shell aggregate concrete by pull-out test

An experimental investigation was carried out to study the influence of coconut shells as coarse aggregate on the bond strength of concrete. Pull-out tests under monotonic loading were carried out. A total 30 concentrically reinforced cubes were cast and tested. Of these, six were made of control mix and remainder were made from concrete with different replacement of coarse aggregate with coconut shells. High yield strength deformed bars of 12 mm and 16 mm diameter were used as reinforcement. M25 grade concrete and different replacement of coarse aggregate with the coconut shells were considered. The test results indicated that as percentage of replacement of coarse aggregates with coconut shells increases the concrete bond strength decreases.