Revealing corrosion parameters of steel in alkali-activated materials

Application of electrochemical methods for studying steel corrosion in alkali‐activated materials

“…Indeed, a study of the corrosion of steel in AAMs based on blast furnace slag/fly ash blends [25] found B = 45-58 mV for actively corroding steel, and B = 13-20 mV for passive steel, differing considerably from the above values (see Section 5.4). Similar values of B = 55-63 mV and B = 15-25 mV for the active and the passive state, respectively, of steel in various AAMs were obtained by Runci et al [90] It is further noted that, in the context of on-site applications, it has been inferred that the LPR technique does not give reliable results for submerged concretes (that may be water saturated) or where the steel is in the passive state with restricted access to oxygen. [9] Despite the apparent inability of the LPR method in combination with the Stern-Geary equation to quantify the corrosion rate of the steel under localised attack, the polarisation resistance (R p ) derived from LPR measurements is a useful indicator of the state (passive or actively corroding) of reinforcement steel.…”

“…Indeed, a study of the corrosion of steel in AAMs based on blast furnace slag/fly ash blends [ 25 ] found B = 45–58 mV for actively corroding steel, and B = 13–20 mV for passive steel, differing considerably from the above values (see Section 5.4). Similar values of B = 55–63 mV and B = 15–25 mV for the active and the passive state, respectively, of steel in various AAMs were obtained by Runci et al [ 90 ] It is further noted that, in the context of on‐site applications, it has been inferred that the LPR technique does not give reliable results for submerged concretes (that may be water saturated) or where the steel is in the passive state with restricted access to oxygen. [ 9 ]…”

“…Table 2). Nevertheless, a recent study [ 90 ] that compared chloride‐induced steel corrosion in AAMs based on blast furnace slag, fly ash, and blast furnace slag/fly ash blends proposed an OCP of −400 mV versus SCE as a criterion for determining whether the steel reinforcement in AAMs is in the active or the passive state.…”

Effect of Electrochemical Corrosion on the Properties of Modified Concrete

“…These electrochemical reactions are most often caused by the flow of electric current through the steel-concrete interface, during which electrochemical corrosion influences both the mineral matrix and the reinforcement [3,5,[32][33][34].…”

“…However, recent studies in the field of the effect of carbon nanostructures on the properties of mineral matrices consider these modifiers from a point of view of their impact on electrochemical corrosion [32,39]. In works on forming an electrically conductive cluster structure by introducing a suspension of nanodispersed materials [37], it was found that the low volume resistivity of concrete promotes the formation of galvanic coupling with steel reinforcement, yielding a potential reduction in the impact of electrochemical corrosion on reinforced concrete.…”