Corrosion products and corrosion-induced cracks of low-alloy steel and low-carbon steel in concrete

The distribution of corrosion products at the steel-concrete interface and the pattern of corrosion-induced cracks were characterized using X-ray computed tomography (X-CT) and environmental scanning electron microscopy (ESEM). A novel low-alloy reinforcing steel (LA steel) and the conventional low-carbon reinforcing steel (LC steel) embedded in concrete were subjected to impressed current accelerated corrosion. The results of Raman spectroscopy showed that non-protective lepidocrocite (γ-FeOOH) was the main corrosion products for LC steel, while stable and protective maghemite (γ-Fe2O3) and less crystallized feroxyhite (δ-FeOOH) and ferrihydrite (5Fe2O3·9H2O) were identified in the Cr-enriched inner rust layer of LA steel.