In this study, ternary ecological concrete (TEC) mixtures were produced with partial substitution of the ordinary Portland cement (OPC) by 10%, 20%, and 30% of sugar cane bagasse ash (SCBA) and silica fume (SF); a control mixture (100% OPC) was prepared according to ACI 211.1 standard. The studied TEC specimens were reinforced with AISI 304 stainless steel and AISI 1018 carbon steel rebars. TEC reinforced specimens were immersed in two different electrolytes, a control (DI-water) and 3.5 wt.% MgSO4 solution, for 180 days. The electrochemical corrosion was monitored by corrosion potential (Ecorr) according to ASTM C-876-15 standard, and the linear polarization resistance (LPR) technique using ASTM G59 standard. The Ecorr and current density icorr results show that AISI 304 stainless steel rebars have a high corrosion resistance, with icorr values below 0.1 µA/cm2, which is interpreted as a level of negligible corrosion. The best corrosion performance was found for the TEC mixture made with a 20% addition of blend of sugar cane bagasse ash-silica fume (SCBA-SF) to the OPC.

Polarization Resistance. LPR (ASTM-G59). The specimens were buried in a soil type MH contaminated with 0, 1, 2, and 3 wt.% NaCl as aggressive agent by weight of soil, the exposure time was 260 days where, the results show that when the presence of NaCl in the soil was increased to 2 and 3% the levels of corrosion are from high to very high in all concretes, presenting a little better performance the concretes reinforced with galvanized steel and a small benefit could be identified or related to the properties of a denser and less impermeable matrix that presented the concrete mix made with cement CPC 30R RS.

Novel green concrete (GC) admixtures containing 50% and 100% recycled coarse aggregate (RCA) were manufactured according to the ACI 211.1 standard. The GC samples were reinforced with AISI 1080 carbon steel and AISI 304 stainless steel. Concrete samples were exposed to 3.5 wt.% Na2SO4 and control (DI-water) solutions. Electrochemical testing was assessed by corrosion potential (Ecorr) according to the ASTM C-876-15 standard and a linear polarization resistance (LPR) technique following ASTM G59-14. The compressive strength of the fully substituted GC decreased 51.5% compared to the control sample. Improved corrosion behavior was found for the specimens reinforced with AISI 304 SS; the corrosion current density (icorr) values of the fully substituted GC were found to be 0.01894 µA/cm2 after Day 364, a value associated with negligible corrosion. The 50% RCA specimen shows good corrosion behavior as well as a reduction in environmental impact. Although having lower mechanical properties, a less dense concrete matrix and high permeability, RCA green concrete presents an improved corrosion behavior thus being a promising approach to the higher pollutant conventional aggregates.

This study analyzes the electrochemical behavior of AISI 1018 steel as reinforcement in concrete exposed to the Xalapa city (urban environment) and seawater (marine environment). Two concrete mixtures were made, with ratio w/c of 0.45 and 0.65, according to the method of ACI 211.1. The specimens underwent three types of curing, the first was submerged in water for 27 days as indicated by the ONNCCE regulations, the second was cured as it is done on oeuvre (moisturizing the elements in the morning and in the afternoon) and the third one exposing to the environment (without applying water), before placing them in the exposition environment. The results of more than 340 days of monitoring of Ecorr and Icorr demonstrate that the marine environment is the most aggressive in the corrosion of reinforced concrete, with a better performance of the concrete of ratio w/c=0.45 and with a curing according to normative.