STUDY ON DETERIORATION MECHANISM OF POROUS CONCRETE BY CaCl₂aq

Abstract

Main purpose of the present research is to clarify the chemical deterioration mechanism of porous concrete by CaCl₂ solutions as a deicer. In the present study, cement paste specimens were fabricated with ordinary Portland cement and soaked in high concentration CaCl₂ solution. Observation of deterioration process and X-ray diffraction analysis were conducted on both chemical deterioration products and binder exfoliated from aggregate surfaces. As a result, it was found that CaCl₂ solution penetrated into binder, then produced deterioration product either in the interfaces of binder and aggregates causing the interface peeling, or right under the carbonated surface of binder causing stratified peeling. In both cases, collapse of porous concrete structure has been finally found. Also, it was found that surface of binder has high resistance against the CaCl₂ attack in the existence of CaCO₃ which was produced from hydration product Ca(OH)₂.