Experimental methods for the analysis of the durability behavior of concrete joints

This article addresses the applicability of experimental methods for the evaluation of concrete durability on localized structural weaknesses posed by joints. Three different types of exposure are analyzed: chloride penetration, carbonation, and freeze-thaw attack. First, established experimental methods for the characterization of the durability of plain concrete are presented and their general applicability on concrete joints is discussed. The experimental program focuses on the execution of selected tests on laboratory specimens with and without joints. Indicator tests for both chloride penetration and carbonation are generally feasible, but require attention to specimen preparation. Rapid chloride migration yielded inconclusive results, while uniaxial chloride diffusion coefficient of concrete joints cannot be determined because of the areal extent of profile grinding. For the same reason, the characterization of the resistance to freeze-thaw cycles through surface deterioration is not applicable for concrete joints. The structural damage was instead successfully qualified through direct tension tests.