Sub-surface simulated damage detection using Non-Destructive Testing Techniques in reinforced-concrete slabs

Abstract

Most commonly occurring defects in RC (Reinforced Concrete) bridge decks include voids, spalling, corrosion of reinforcement, leaching, scaling, cracking, honeycombing and delamination/debonding. Research related to the use of different NDTs (Non-Destructive Testing) techniques to locate and identify different defects and its severity have been conducted in the past. Previous research work indicates that no particular technique is complete and each has its own advantages and limitations. This paper discusses the error values in identification of the damage in reinforced concrete using NDTs. This research uses a total of five NDTs and their combination to detect the defects. For this, a total of nine 1800 mm × 460 mm reinforced concrete slabs with varying thicknesses of 100 mm, 150 mm and 200 mm have been prepared. These slabs have been embedded with artificial defects like voids, debonding, honeycombing, and corrosion. The experimental research shows that combining multiple techniques together in evaluating the defects give significantly lower error and higher accuracy compared to that from a standalone test. Combination of multiple techniques such as stress wave, electromagnetic wave, infrared thermography and other electrochemical methods have been used for damage detection in reinforced-concrete slabs.