A Statistical Approach to Refine Design Codes for Interface Shear Transfer in Reinforced Concrete Members
Mahmoodreza Soltani, Brandon E. Ross, and Amin Khademi
Appears on pages(s):
cold joints; design model; lightweight concrete; normalweight concrete; sensitivity analysis; shear friction
Interface shear transfer (IST) theory describes the mechanisms by which shear force is transferred across concrete-to-concrete
interfaces. Previous research has shown that current code-based IST models produce inconsistent levels of accuracy for different values of design parameters (that is, material strength, reinforcement density, and member size). Objectives for the current research were to identify parameters having the greatest impact on the IST capacity, and to create a model that produces consistent levels of accuracy. Using a database of experimental results, an artificial neural network model was created to estimate IST strength and to perform a sensitivity analysis of the parameters affecting capacity. The sensitivity analysis demonstrated that compressive strength of concrete is the most significant parameter affecting IST capacity. A multiple linear-regression analysis was also performed to aid in
development of a new IST design model. Based on the results of
the sensitivity analysis, and in contrast to current model codes, the proposed IST model directly accounts for compressive strength of concrete as one of the model parameters. The model is strongly correlated (R2 ≥ 0.88 and p-values << 0.01) with the experimental data, and relative to current codes, it produces more consistent levels of accuracy across ranges of design parameters.