The effects of organic corrosion inhibitor on concrete properties and frost resistance

Abstract

Organic compounds are widely used as organic corrosion inhibitors (OCIs) for inhibiting chloride-induced corrosion in reinforced concrete. However, the effects of these organic compounds on concrete properties are unclear. In this paper, the effect of three types of commonly-used organic corrosion inhibitors (easter-, alcoholamine-, and carboxylic acid-based) on pore size distribution, hydration products, and microstructure is analyzed using the nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscope (SEM). Moreover, the mechanical properties, surface scaling resistance, and capillary absorption of OCIs-modified concrete after exposure to salt-frost cycles are also investigated. The obtained results show that the used OCIs do not affect the hydration product species. Easter-based OCIs can significantly decrease the proportion of larger pores, thus enhancing the compressive and reducing the capillary absorption rate. Concrete frost resistance has shown improvement after adding alcoholamine-, and carboxylic acid-based OCIs. However, easter-based OCIs may induce severe surface scaling by increasing the saturation of concrete pore water. The obtained results provide an experimental basis guiding the application of OCIs in cold regions.