In-Plane Shear Response of Externally Bonded CFRP on Autoclaved Aerated Concrete

Abstract

A novel concept of hybrid fiber-reinforced polymer (FRP) - Autoclaved Aerated Concrete (AAC) sandwich panels have proven to be a structurally efficient combination for lightweight structural components. The FRP composite material was made of carbon reinforcing fabrics embedded in an epoxy resin matrix. The carbon fiber reinforced polymer (CFRP) reinforcement was applied on the top and bottom faces of the AAC panel and several innovative processing techniques were used including hand lay up as well as vacuum assisted resin transfer molding (VARTM). This research is aimed at understanding the interface formed by carbon fiber processed on to Autoclaved Aerated Concrete (AAC) surface using the hand lay up and VARTM process technique, and implementing a solution to eliminate excessive resin absorption during processing. A weak interface creates potential problem such as water seepage, fiber wrinkling, premature failure caused by debonding at the interface and moisture included delimitation. Carbon fiber Sikadur HEX 103C and low viscosity epoxy resin Sikadur 300 were considered in processing of AAC specimens. A surface treatment using block filler is proposed that demonstrated a significant reduction in resin absorption by AAC surface along with adequate bonding between FRP and AAC surface. A numerical modeling was also conducted to predict the In-Plane shear strength between FRP and AAC, and theoretical results found in good accordance with the experimental results.