Shear testing of concrete sandwich panels with carbon fiber grid reinforcement

C-Grid is a Carbon Fiber Reinforced Polymer (CFRP) product composed of carbon fibers and epoxy resin forming a grid with elements rotated 45 degrees from the horizontal. In this investigation C-Grid connectors are proposed for connecting two-wythe sandwich panels used in cladding systems. The main objective of this research was to evaluate the fatigue performance of this product by testing small and medium scale wall panels subject to monotonic and cyclic loading. Test specimens consisted of two outer concrete wythes, a center concrete wythe and two foam layers, with each foam layer separating the center concrete wythe from the outer concrete wythes. Fifteen inch and 48 inch tall specimens were subjected to monotonic loading and various levels of cyclic loading. Monotonic testing indicates similar behavior for same type of specimens. Results of the cyclic tests show that the number of cycles to failure tends to increase significantly for cyclic loads below 30% of the monotonic failure load. Analysis of the results of 15 inch and 48 inch tall specimens indicate that 48 inch tall specimens better represent the full size sandwich panel behavior than the 15 inch tall specimens. An analytical model of both types of specimens was created in SAP 2000 indicating good agreement with the experimental results.