Effects of coral sand powder and corrosion inhibitors on reinforcement corrosion in coral aggregate seawater concrete in a marine environment

Abstract

This paper investigates the effects of coral sand powder (CSP) and corrosion inhibitors (SBT®‐ZX(V), SBT®‐RMA(II)) on reinforcement corrosion in coral aggregate seawater concrete (CASC) in a marine environment. A reasonable time‐variation model for reinforcement corrosion in CASC is proposed and verified. Based on the time‐variation model and chloride diffusion model, the cracking time and service life of CASC are predicted. The results show that the replacement of cementitious materials by 5% CSP can improve the corrosion resistance of steel bar in CASC. Both SBT®‐ZX(V) and SBT®‐RMA(II) can reduce the corrosion rate of steel bar in CASC, and this effect of SBT®‐RMA(II) is more effective than that of SBT®‐ZX(V). Among all CASC, CASC containing 5% CSP and SBT®‐RMA(II) possesses the best corrosion resistance. The results also reveal that the corrosion current density of steel bar in CASC increases firstly and then decreases over time. The ascending segment of the fitting curves for reinforcement corrosion in CASC conforms to the logarithmic‐type time‐variation model, and the descending segment of the fitting curves for reinforcement corrosion in CASC conforms to the exponential‐type time‐variation model. The cracking time and service life of CASC containing 5% CSP and SBT®‐RMA(II) will reach more than 10 years when the thickness of protective layer is 30 mm.

Study on Deterioration Characteristics of Low‐Carbon Steel’s Mechanical Properties and Fracture Mechanism under Marine Engineering Environment

“…Wang et al studied the effects of coral sand powder and corrosion inhibitors on reinforcement corrosion. ey proposed and verified the time-varying model of steel corrosion [13]. Besides experimental studies, a series of mathematical algorithms and theoretical models have been developing gradually and becoming mature, which enriches the steel corrosion theory and provides theoretical supports for corrosion resistance [14].…”

Axial behavior of seawater sea-sand coral concrete-filled basalt fiber-reinforced polymer tubular columns containing pre-bonded basalt fiber-reinforced polymer bars

“…However, as a type of lightweight aggregate concrete, the loose and porous nature of coral aggregates leads to the generally low strength of coral aggregate concrete and poor durability under the long-term erosion of seawater and waves (Wu et al, 2018; Yu et al, 2020). More fatal is, since the coral aggregate concrete contains a large number of chloride ions, ordinary steel can not be used directly as reinforcements (Huang et al, 2020; Niu et al, 2020; Wu et al, 2020a; Wang et al, 2020a). All these unfavorable factors greatly limit the scope of its application.…”