Effect of size and preconditioning of concrete cores against sulfate attack (test)

L.R. SANTILLÁN; Y.A. VILLAGRÁN-ZACCARDI; E.F. IRASSAR; C.J. ZEGA

Proceedings of the 75th RILEM Annual Week 2021

Springer Cham

Año: 2023; p. 296 - 305

Some of the proposed accelerated tests for evaluating the sulfate resistance of concrete address only the Portland cement, as the hydrated cement paste contains unstable compounds that may react with sulfate ions, while others are based on concrete performance. In search of comprehensive and practical assessments, some researchers proposed the evaluation of core samples as performance tests. The kinetics of attack is accelerated by further exposing the inner matrix of the concrete to the aggressive solution. Another accelerating strategy reported in the literature is to precondition the samples by vacuum saturation with sulfate solution, which speeds up the penetration of sulfate ions into concrete at the start of the test.In this work, both strategies were applied to develop an accelerated performance test for concrete. Core specimens of two sizes were drilled off from two concrete types and exposed to a highly concentrated sulfate solution. Two preconditioning procedures were applied to the samples prior to exposure. The results show a large reduction in failure time when a vacuum step is used as preconditioning (one-sixth). This methodology could be useful in recycled concrete production to evaluate the potential reactivity of source concrete against sulfates.