Comparison of Methods for Texture Assessment of Concrete Surfaces

This article describes how the bond strength of the interface between concrete layers cast at different times is important to ensure the monolithic behavior of reinforced concrete (RC) composite members. The roughness of the substrate surface has a significant influence in this scope. Current design codes use a qualitative approach based on visual inspection to assess roughness. This procedure is highly dependent on the designer and, therefore, can lead to inaccurate results. Previous studies conducted by the authors proved that it is possible to use a quantitative criterion to classify roughness. This paper describes an experimental study conducted to compare four roughness quantification methods: the processing of the digital image (PDI) and the two-dimensional (2D) laser roughness analyzer (2D-LRA) methods, both developed by the authors; an upgrade of these, using a three-dimensional (3D) laser scanner; and the sand patch test (SPT), a simple and widespread method. The 2D-LRA proved to be the best from the four methods considered because it gives a quantitative assessment of the roughness with adequate accuracy, is nondestructive, easy and fast to use, and is cost effective.