Corrosion Behavior of AISI 1018 Carbon Steel in Localized Repairs of Mortars with Alkaline Cements and Engineered Cementitious Composites

Abstract

The selection of materials for repairs of reinforced concrete structures is a serious concern. They are chosen for the mechanical capacity that the repair mortar achieves. However, several important characteristics have been left aside, such as the adhesion of the repair mortar with the concrete substrate, the electrical resistivity and—hugely important—the protection against corrosion that the repair material can provide to the reinforcing steel. The aim of this work was to study the corrosion behavior of AISI 1018 carbon steel (CS) in mortars manufactured with alkaline cements, engineered cementitious composites (ECC), and supplementary cementitious materials (SCM). Two types of ordinary Portland cement (OPC) 30R and 40R were used. The constituent materials for the mortars with ECC mixture mortars they use OPC 40R, class F fly ash (FA), silica fume (SF) and polypropylene (PP) fibers. The sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) were used as activating agents in alkali activated cements. The reinforced specimens were immersed in two different electrolytes, exposed to a 3.5 wt % of NaCl and Na2SO4 solutions, for 12 months and their electrochemical behavior was studied by half-cell potential (Ecorr) and linear polarization resistance (LPR) according to ASTM C876-15 and ASTM G59-97, respectively. The results obtained indicated that, the mortar they have the best performance and durability, is the conventional MCXF mortar, with OPC 30R and addition of 1% polypropylene PP fiber improves the behavior against the attack of chlorides and sulfates.

Effect of Cathodic Protection on Reinforced Concrete with Fly Ash Using Electrochemical Noise

“…The Fly Ash (FA)—Class F type addition was according to ASTM C618-94a [ 54 ], obtained from a coal-fired power plant in Coahuila, Mexico. The Research group has tested supplementary materials as a partial substitute cement and has found good results with fly ash [ 2 , 12 , 19 , 22 , 23 , 27 ]. Therefore, in this study Fly Ash was used as a partial substitute for OPC with a replacement percentage of 15%.…”

“…In the construction industry, corrosion of steel reinforcement is one of the main issues. It is considered the leading cause of the premature deterioration of reinforced concrete structures [ 1 , 2 , 3 ]. The most predominant factors affecting the steel bars can be physical, mechanical, biological, or chemical [ 4 , 5 ].…”

“…The cement industry is one of the two largest producers of carbon dioxide (CO 2 ), generating between 5–8% CO 2 total emissions to the environment. In the future, the CO 2 emissions are predicted around 10–15% [ 2 , 10 ]. The supplementary cementitious materials (SCM) are employed to reduce CO 2 emissions and replace, in a portion, Portland cement [ 2 , 11 , 12 , 13 , 14 , 15 ].…”

Predicting the life cycle durability and ecological performance of cementitious coatings with a fuzzy‐stochastics–based approach

“…As part of the offshore structures, protective coatings effectively alleviate the entering of harmful ions, slow down the chloride ingress (Meng et al., 2022; Tanaka & Koishi, 1999), extend service life, and reduce the needs for new constructions (Sarma & Adeli, 2002). Among all types of protective coatings, cement mortar coating is widely used due to its desirable properties of good bonding with concrete substrate and resistance to abrasion and elevated temperature (Maldonado‐Bandala et al., 2020; Nguyen et al., 2009). However, the durability performance of cement mortar coatings is limited by its brittle nature.…”