Investigation of the bond between bamboo and ribbed steel reinforcements and the surrounding concrete by pull-out test

Abstract

Traditional housing did not use expensive materials like steel reinforcement, yet some have outlived sandcrete or mud-brick housing. One means to build at a low cost is to supplement high-cost materials with low-cost types, which have comparable strength. This study compares the bond between bamboo (Bambusa vulgaris and Bambusa vittata) reinforcement as well as ribbed steel enforcement and the surrounding concrete by pull-out test. Bamboo specimens were split and cut into the dimensions of 600 mm × 20 mm ×10 mm. Sixty (60) samples of each of the two varieties were prepared, thirty (30) were coated with tar oil as waterproof agent to a length of 200 mm and embedded into fresh concrete samples and allowed to cure, while another 30 did not receive any coating. Thirty (30) specimens of 12.5 mm diameter of ribbed steel rods of length 60 mm were used as control Materials for the pull-out test were also embedded in the centre of 150 mm concrete cubes and left to cure for 28 days. The load required to pull the steel rods from concrete (5.49±0.22 kN) was greater than those for both coated Bambusa vulgaris and Bambusa vittata (1.67±0.11 kN – 1.67±0.12 kN) and uncoated Bambusa vulgaris and Bambusa vulgaris vittata (2.04±0.14 kN– 2.14±0.19 kN) bamboo. The differences were significant (p<0.05). The pull-out was also conducted in conformity with the Bureau of Indian Standard (IS) 2770: 1997.