EFFECT OF SELF HEALING PROMOTED MATERIALS BLENDED WITH CARBOXYLIC ACID ON PERMEABILITY

A kind of calcite crystalline proliferation cementitious mixture consisting carboxylic acid and carbonate salts used as self healing promoted materials (SHPM) was presented. Study was focused upon formulating the leaching and deposition equilibrium process of calcite crystals proliferated by SHPM during direct hydraulic permeability test. Results of permeability experiments and Environmental Scanning Electron Microscopy (ESEM) observation confirmed the properties of self healing of the materials. Comparing to blank paste sample, the permeability of paste coated with SHPM reduced significant with the elapse of time, while the permeability of paste blended with magnesium salt and cured in dilute carboxylic acidic solution dramatically increased during the leaching period. Compared to maleic acid and malic acid, tartaric acid mixed in SHPM had a high efficiency to modify the crystalline morphologies of deposited calcite and aragonite. Study is aimed to give a comprehension of self healing process of concrete in ambient weak acidic saturated environment.