Comparative study on induced macrocell corrosion phenomenon in repaired ordinary reinforced and self-compacting concrete structures

Abstract

This paper aimed at an experimental investigation of the comparative corrosion phenomenon in the reinforcing steel of repaired chloride contaminated self-compacting concrete (SCRC) and ordinary concrete (OC) patches. This research is a continuation of a previous study in which macrocell specimens were prepared with OC having different chloride contaminations simulating the actual patch repair in the construction field. Here, in this research, the same specimens were prepared with SCRC to investigate more deeply the macrocell phenomenon in SCRC, which received limited attention in the past. Four prismatic specimens with two sets of 5 and 3% chloride contaminated SCRC at the two ends were prepared respectively, and the middle portion of these specimens was cast after 24 h with uncontaminated SCRC simulating the actual patch repair in the field. After 1 year of experimental observations of corrosion potentials and corrosion rates, interesting and novel results were obtained in comparison with OC and SCRC specimens.

A comparative study on corrosion kinetic parameter estimation methods for the early stage corrosion of Q345B steel in 3.5wt% NaCl solution

“…Corrosion current has therefore long been considered an important research subject for corrosion researchers. A number of techniques have been developed and widely applied in various fields, including nuclear power systems [2][3][4], the petrochemical industry [5][6][7][8][9], aviation and space flight [10], and the construction of reinforced concrete structures [11][12][13][14][15]. These techniques can be classified into two types: non-electrochemical and electrochemical measurements.…”

Re-Corrosion in Simulated Refurbished Patches of Corroded Lightweight Reinforced Concrete Structures

“…The details of the mixing procedure for LWC are published elsewhere by author [7]. The test specimens of the current research were similar in size and dimension to the previous research [10][11][12], with necessary changings to make current research more reliable and accurate. Same like previous research, in the current research the phenomenon of macro-cell as illustrated in Figure 1, was intended to be investigated in LWC.…”

“…The more details of the mix design of LWC can be found elsewhere [7]. The mix proportion used in this investigation for LWC specimens is shown in Table 1, while, the mix proportion and preparation for SCC specimens can be found somewhere else [12]. For reinforcement, carbon steel bars of 10 mm in diameter were used in specimens after polishing by sand paper.…”

“…The middle portion of these specimens was cast after one day with no admixed chloride to replicate the repaired portion in the field conditions so to prevent or minimize the further progress of corrosion. Further, details about the specimens' preparation can be obtained from authors published works [10][11][12].…”

“…Structural patch repair is the most commonly applied practice in the construction and repair industry though such repairs are found vulnerable [9]. Authors of this paper have previously investigated re-corrosion phenomenon in the repaired concrete patches of the reinforced OC and SSC [10][11][12]. The question whether this phenomenon occurs in LWC and the comparison of corrosion behavior between SCC and LWC are the main objectives of this paper.…”