Bonding performance of reinforced and oil shale residue concrete

Oil shale residue concrete is prepared by utilizing oil shale semi-coke. It has advantages such as low cost and a high solid waste utilization rate. The study of its bonding-slip characteristics with steel bars is a prerequisite for their application in engineering structures. To study the bonding-slip performance of reinforced oil shale residue concrete, 12 half-beam specimens were designed for the bonding performance test. The test parameters included the substitution rate of oil shale residue, bonding length, and cover thickness. The influences of the aforementioned factors and variables on the stress-slip curve and bonding strength were analyzed. The results showed that the anchoring bond length had the greatest impact on the average bonding strengths of the steel bar and concrete. As the bonding length increases from 5d to 10d, the average bonding strength decreased by approximately 18%. The cover thickness had the second-greatest influence on the bonding strength. As the cover thickness increased from 20 to 30 mm, the average bonding strength increased by more than 12%. The substitution rate of the oil shale residue had the least effect on the average bonding strength, and as the substitution rate increased, the bonding strength decrease with a minor magnitude. Through verification, the bonding-slip constitutive model obtained by fitting the experimental data was found to fit the experimental values well.