Journal Article•
Steel corrosion in concrete -- how does it occur?
TL;DR: In this article, the authors designed a questionnaire to determine if a predicated threshold for the occurrence of corrosion of a piece of steel is real and whether a threshold exists.
Abstract: THE TESTS DESCRIBED IN THIS PAPER WERE DESIGNED TO: IDENTIFY THE MECHANISM BY WHICH CORROSION OF STEEL IS INITIATED, PROVIDE QUANITATIVE INFORMATION ABOUT THE EFFECTS OF CHLORIDES, AND DETERMINE IF A PREDICTABLE THRESHOLD OF CORROSION EXISTS LABORATORY STUDIES ARE REPORTED ON THE CORROSION OF BARE STEEL RODS IN ENVIRONMENTS SIMULATING POROUS CONCRETE CONTAMINATED WITH CHLORIDES THE INITIATION OF CORROSION IS SHOWN TO REQUIRE FREE OXYGEN AT THE STEEL SURFACE AND A RATIO OF CHLORIDE TO HYDROXYL ION ACTIVITY OF AT LEAST 06 A PROBABILITY MODEL IS USED TO EXPLAIN THE CHLORIDE EFFECT AND TO PREDICT THE THRESHOLD VALUE CAUSING CORROSION /AUTHOR/
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TL;DR: In this paper, a review of the state-of-the-art in the area of critical chloride thresholding of reinforced concrete is presented, highlighting the strong need for a practice-related test method, and focusing especially on experimental procedures.
982 citations
TL;DR: In this paper, the mechanisms that govern the transport of ions, moisture, and gas are described, and different chemical degradation phenomena are reviewed, such as sulfate attack from external sources and formation of ettringite and thaumasite.
562 citations
TL;DR: In this paper, the chloride threshold to develop active corrosion of the reinforcing steel embedded in concrete is defined based on the current measurements and expressed as total, free and Cl−/OH− ratio, and the threshold in the case of free chlorides is a bit higher than that found in a previous work for synthetic pore solution, although the two types of data can be fitted together finding a good correlation.
493 citations
TL;DR: In this paper, the state of the art on the CTL for steel corrosion in concrete, concerning its measurement, representation, influencing factors and methods to enhance the threshold level (CTL).
472 citations
01 Jan 1983
TL;DR: In this article, samples of the capillary pore solution associated with hardened cement pastes containing various proportions of silica-fume and sodium chloride have been expressed at different stages of curing and analyzed to determine concentrations of dissolved ions.
Abstract: Samples of the capillary pore solution, associated with hardened cement pastes containing various proportions of silica-fume and sodium chloride, have been expressed at different stages of curing and analysed to determine concentrations of dissolved ions. The results indicate that partial replacement of Portland cement by increasing percentages of silica-fume causes a regular decrease in alkalinity of the pore solution and a reduction in the chloride-binding capacity of the material. Possible implications regarding the level of corrosion protection afforded to embedded steel are considered.
300 citations