Title: Resistance of Segmental Joints to Chloride Ions

Author(s): Guoping Li, Hao Hu, and Cai Ren

Publication: Materials Journal

Volume: 113

Issue: 4

Appears on pages(s): 471-481

Keywords: compressive strain; epoxied joints; monolithic concrete; wet joints

DOI: 10.14359/51688931

Date: 7/1/2016

Abstract:
Previous studies regarding resistance to chloride ions in concrete mainly focused on monolithic concrete, whereas the effect of joints was often ignored. To study the effect of joint type and load condition on the resistance of segmental joints to chloride ions, a salt solution immersion test was conducted in two series. Series I, comprising seven monolithic beams loaded at various strain levels, was used to quantify the effect of the load condition in terms of strain. Series II, comprising six specimens with direct wet joints, roughened wet joints, and epoxied joints, was used to study the resistance of segmental joints to chloride ions at zero strain and a compressive strain corresponding to approximately 0.25 times the axial compressive strength of concrete. After immersion, the chloride ion content was determined at different depths in the specimens. Based on the diffusion coefficients fitted according to Fick’s second law, the authors conclude the following: for specimens with a certain level of compressive strain or without strain, monolithic concrete exhibits optimal resistance to chloride ions, better than the direct wet joints and roughened wet joints. However, the diffusion coefficients of epoxied joints fluctuate.