VACUUM AND PRESSURE BAGGINGS TO IMPROVE THE CFRP WRAPPINGS OF CONCRETE CYLINDERS

摘要

The vacuum bagging and pressure bagging commonly used in the aerospace industry are applied in the FRP wrapping of concrete cylinders. Both curing methods can remove the air voids within the composite wrapping during hand lay-up and develop a strong bond between the interface of concrete and FRP. Concrete specimens of designated strengths are wrapped with FRP using hand lay-up, vacuum bagging and pressure bagging, respectively, to study the applicability of these curing techniques in the retrofit of infrastructures. In order to verify that these curing techniques can be applied to aging or deteriorated structures, concrete cylinders are axial loaded and predamaged to retain 60%, 70% and 80% of their original compressive strengths, respectively, to generate cracked and rugged surfaces. A surface treatment and primer coat are applied to smear the surface defects. FRP wrapping using both vacuum bagging and pressure bagging are conducted thereafter. The residual compressive strengths are measured to assess the performance of these two methods.