Corrosion effect on reinforced concrete with the addition of graphite powder and its evaluation on physical-electrochemical properties

Abstract

The corrosion of reinforced concrete without and with the addition of graphite powder with low carbon content was evaluated. Phase identification processes and physical-electrochemical properties of the concrete were analyzed using X-ray diffraction techniques (XRD), scanning electron microscopy (SEM), half-cell potential, electrochemical noise (EN) and linear polarization resistance (LPR). Samples were studied for 168 days in saline solution. The results show that, when adding graphite powder in an amount of 2.5% by weight of cement, the compressive strength increased if compared with the control sample. The electrochemical tests show that the higher the level of graphite replacement, the higher the level of corrosion in concrete.

Influence of Recycled High-Density Polyethylene Fibers on the Mechanical and Electrochemical Properties of Reinforced Concrete

“…Figure 11 shows the results of corrosion potential in reinforced concrete, and w the values obtained, it is possible to diagnose the degree of corrosion of the rebars emb ded in the concrete [63]. In the first 10 days of immersion, for the samples with synth fibers, more negative Ecorr values of between −300 mV and −520 mV were observed, s gesting a 90% probability of corrosion in the rod.…”

“…Figure 12a shows the noise measurements related to the incorporation of HDPE fibers into the cement paste, where high and low signals of electrochemical noise resistance are presented. These values range from a minimum to a maximum of 1 × 10 5 and 1 × 10 10 Ω•cm 2 , where high values of Rn indicate passivation in the metal and a negligible corrosion rate, which may be due to the formation of oxide films on the surface of the rebar [63]. These values are related to the corrosion rate, as shown in Figure 12b.…”

“…Using the values of current density (i corr ) and corrosion rate, the service life of the reinforcing steel in concrete can be estimated [62]. According to Flores-Nicolás et al [63], for i corr values lower than 0.1 µA/cm 2 , the corrosion condition of the steel bar is negligible; for values in the range of 0.1 to 0.5 µA/cm 2 , the level is moderate; for values from 0.5 to 1 µA/cm 2 , the level is high; and finally, for values higher than 1 µA/cm 2 , the corrosion degree is very high in the steel/concrete system. Electrochemical impedance spectroscopy (EIS) is a technique for characterizing a wide variety of electrochemical systems and can be used to investigate the dynamics of bound or moving loads in the volume of interface regions or any liquid or solid material.…”

Comparative Studies on the Anti‐Corrosive Action of Waterproofing Agent and Plant Extract to Steel Rebar

“…[ 45 ] In the method, the probability of the corrosion grade of the slab rods established with the recorded CoP, which made it feasible for pointing out the corrosion level of rebar in concrete infrastructures. [ 46 ] The extent of corrosion damage of the SRC was considered to be low corrosion (LoC) or less than 10% probability at measurement time if the mean CoP on the defined areas/portions of the RfC structures was more positive than −126 mV versus SCE. Moreover, the corrosion level of SRC presupposes to be intermediate corrosion risk (InC) if its mean CorrP was recorded between −276 and −126 mV versus SCE.…”

Evaluation of Corrosion Condition of Some Steel-Reinforced Concrete Infrastructures Available In Pokhara Valley of Nepal

“…In the HCPM technique, the corrosion conditions of the SRC infrastructures are ascertained with the noted potentials in line with the ASTM C876-15 standard (2015). In this standard, the corrosion conditions of the steel rebar ascertain with the recorded ϕ corr data, which is proving to be one of the reliable, easiest and cost-effective techniques to know the corrosion conditions of the SRC infrastructures (Flores-Nicolas et al 2021). The corrosion degree of steel considered to be low (i.e., < 10% corrosion) at the time of study when the average ϕ corr is in the noble direction than −126 mV.…”