Abstract
The aim of this study was to elucidate the degradation mechanism of post-installed adhesive anchor in alkaline solution and to establish a method for evaluating its alkali resistance properties. We investigated the mechanical properties of the adhesive anchor in potassium hydroxide (KOH) solution with reference to ACI 355.4-11 standard. Changes in chemical structure of the adhesive in the alkaline solution were analyzed with infrared (IR) spectroscopy. The results indicated no significant deterioration in the bond strength of the adhesive after 4000 hours of immersion in KOH solution at 40°C. However, unsaturated polyester resin, a component of the adhesive anchor, showed hydrolysis in KOH solution. The hydrolysis reaction was found to accelerate with increasing temperature of the alkaline solution and progress from the surface to inside with increasing time of immersion.
