Corrosion Caused by Sulfur Dioxide in Reinforced Concrete

Abstract

The burning of fuel oil with high sulfur content in diverse industrial segments results in the generation of oxidized sulfur compounds (SO x). These emissions, directly or indirectly, lead to the deterioration of air quality with consequences including the development of lung diseases in the surrounding population, the generation of acid rain and damage to civil constructions, such as public buildings, public squares, historic monuments, bridges, etc. This article describes the mechanisms of corrosion that occur in reinforced concrete deterioration observed in an industrial plant by the action of direct emissions of sulfur dioxide. SO2 in this case study is from the burning of fuel oil high sulfur content from chimney of an industrial boiler. The deterioration of concrete was evaluated in the laboratory showing the formation of calcium sulfate and calcium sulfate hydrate associated with aluminum oxide (Al 2 O 3) and calcium oxide (CaO).

Comparison of Testing Methods for Evaluating the Resistance of Alkali-Activated Blast Furnace Slag Systems to Sulfur Dioxide

“…The gypsum was observed as the main reaction product of degradation reactions because of the action of sulfuric acid [12,13,15,16] or sulfur dioxide [11,53]. The cementitious system did not show any relevant changes in crystalline phase composition throughout the testing interval.…”

“…Still, the decalcification of CSH could take place due to both the action of SO2 and CO2 and the formation of the corresponding reaction products incorporating the calcium ions originating from the binder gel. The gypsum was observed as the main reaction product of degradation reactions because of the action of sulfuric acid [12,13,15,16] or sulfur dioxide [11,53]. The cementitious system did not show any relevant changes in crystalline phase composition throughout the testing interval.…”

Traces of corrosion and air pollution dominate the vision of the common man in any city

“…According to Mainier et al [11] in this process show in the Figure 3 are expected reactions of SO2, water and sulfuric acid with calcium hydroxide free (Ca(OH)2), dicalcium silicate (2CaO.SiO2) and tricalcium aluminate (3CaO.Al2O3), cement constituents, forming crystals or precipitates in concrete matrix with volumes 30 times greater than the initial volumes of these crystals. That way, the increase of the volumes of these crystals will cause a high internal pressure in the cracks causing, consequently, the failure or desegregation (disagreement) of concrete, according to the following reactions: SO2 + ½ O2 + H2O H2SO4…”

“…Fig. 4 -Electrochemical corrosion mechanism for atmospheric corrosion [11] The anodic and cathodic reactions shown in figure 4 show the electron transfer in three corrosive media usually found on metal surfaces, such as acidic, alkaline or neutral and aerated. Pollutants such as SO2, SO3, NOx, CO2 and H2S can provide corrosive acid media.…”

Study on the Sulfuration Mechanism of Concrete: Microstructure and Product Analysis

“…Only a few investigations have been carried out through theoretical research [ 11 ], in situ testing [ 12 ], and accelerated experiments in the laboratory [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Most studies focus on sulfuration depth, and physical and mechanical properties.…”