15 research outputs found
Study on the Chloride Diffusion Coefficient in Concrete Obtained in Electrically Accelerated Tests
A study of the degradation of marine concrete under the coupled effect of wetting–drying cycles and bending loads
Study of chloride penetration in concretes exposed to high-mountain weather conditions with presence of deicing salts
Chlorine diffusion resistivity of sustainable green concrete in harsh marine environments
Resistance of concrete with blast-furnace slag against chlorides, investigated by comparing chloride profiles after migration and diffusion
Long-term chloride migration coefficient in slag cement-based concrete and resistivity as an alternative test method
Lebensdauer von Stahlbetonbauteilen - Empfehlungen für eine modifizierte deskriptive Bemessung
Influence of combined carbonation and chloride ingress regimes on rate of ingress and redistribution of chlorides in concretes
In majority of exposure environments for concrete structures, there is a high probability of the cyclic occurance of both chloride ingress and carbonation. This paper reports a detailed investigation on the influence of carbonation on both the ingress and distribution of chlorides in three different types of concretes, by comparing results from exposure to chlorides, chlorides before carbonation and chlorides after carbonation. Concretes studied were of 0.55 water-binder ratio with 100% Portland Cement (PC), 70% PC + 30% pulverized fuel ash (PFA) and 85% PC + 10% PFA + 5% microsilica (MS) as binders. Chloride profiles were compared to assess the effects of all variables studied in this research. The effect of carbonation was quantified by measuring the consumption of hydroxyl ions (OH-), air permeability and chloride migration coefficient. The results indicated that carbonation of concrete increases chloride transport, but the precise nature of this is dependent on the combined regime as well as the type of binder. In general, it was found that carbonation of chloride contaminated concretes results in a decrease of their chloride binding capacity, that is it releases the bound Cl- in concretes and pushes chlorides inwards, as has been established previously by other researchers. However, it is established in this research that the combined regimes detrimentally affect the service life of concrete structures, particularly when chloride induced corrosion is a concern