Application of Raman Spectroscopy and Polarization Imaging in Durability Evaluation of Concrete Buildings

  • Lianfen Shao

Abstract

The durability of concrete buildings directly affects the safety of building structures. In order to effectively evaluate the durability of concrete buildings, Raman spectroscopy and polarization imaging are used to evaluate the durability of concrete buildings. Through simulation experiments, Raman spectroscopy technology was used to detect the composition changes of corrosion products in the process of artificial accelerated corrosion and rebar alkalization of steel bars, after the steel bars were loaded by direct current. The effect of water-cement ratio and mineral fine admixture on the structure of concrete interface transition zone was studied by polarizing microscopy imaging principle, and the influence of water-cement ratio and mineral fine admixture on the compressive strength of concrete was analyzed. The results show that the typical green rust characteristic spectra were obtained after 12 hours of artificial accelerated corrosion of steel bars in concrete buildings, and the typical γ-FeOH characteristic spectra were collected after 36 hours, which showed that the steel bars were in a high corrosion activity state, the corrosion of steel bars was serious, and the durability of steel bars decreased. The density of Raman spectra did not increase with the extension of electrification time. It showed that the corrosion of steel bar had stopped in the process of re-alkalization treatment; with the increase of water-cement ratio, the micro-hardness of transition zone decreased gradually, the hardness and compactness of cement paste decreased, and the durability of building also decreased; with the increase of water-cement ratio, the structure of transition zone of concrete building interface become worse and the durability decreased significantly; when the water-cement ratio was 0, the content of silica fume was 10% of cement, the compressive strength and durability of concrete were the highest.

Published
2019-07-27