Title: Use of Carbon Fiber Anchors to Improve Performance of CFRP Strengthened Concrete Structures Subjected to Blast and Impact Loads

Author(s): Sarah Orton, Matthew Brune, Joseph Kirby and Matthew Wheeler

Publication: Symposium Paper

Volume: 281

Issue:

Appears on pages(s): 1-20

Keywords: Carbon fiber anchors, impact, blast, CFRP strengthening

DOI: 10.14359/51683618

Date: 12/27/2011

Abstract:
Carbon fiber anchors can serve to improve the performance of externally applied CFRP (Carbon Fiber Reinforced Polymer) strengthened concrete structures because they do not rely on the bond of the CFRP to the concrete to transfer stresses. This paper seeks to identify the residual strength of externally applied CFRP after damage has been delivered by an instrumented drop-weight impact testing device. The paper further investigates effectiveness of carbon fiber anchors (anchors inserted into predrilled holes and fanned out over the CFRP sheet) in impact damaged specimens. The paper reports the results from 14 impact damaged CFRP strengthened 1.42 m (56 in.) long beams with and without anchors. The research found that impacts from the testing device with a drop height greater than 1.83 m (6 ft) significantly reduced the tensile strength of the CFRP. However, with the use of anchors the same strength can be reached in a damaged CFRP specimen as in an undamaged unanchored specimen. The paper also reports on the effectiveness of the anchors when used to strengthen a reinforced concrete slabs subjected to blast loads and a reinforced concrete beam under impact loading and finds that the anchors are able to fully develop the tensile strength of the CFRP under dynamic loading.