Bond characteristics of plain and deformed bars in lightweight pumice concrete

An investigation is conducted to determine the bond characteristics of plain and deformed reinforcing bars in lightweight volcanic pumice concrete (VPC) and normal concrete (NC). VPC and NC are manufactured by incorporating crushed lightweight pumice and gravel aggregates, respectively. Bond tests are conducted on 112 pullout specimens to study the influence of type of concrete (NC or VPC), type of reinforcing bars (plain or deformed), length of embedment (le) and age/strength of concrete on bond strength and failure modes. The load–slip responses, failure modes and bond strengths of VPC and NC are compared at various ages ranging from 1 to 28 days. The performance of Code based and other existing bond equations in predicting bond strength of plain and deformed bars is analyzed by taking into consideration of the influence of failure modes. concrete types and embedded length.