Blast testing of RC slabs retrofitted with NSM CFRP plates

Abstract

In this paper, blast testing was performed on two reinforced concrete specimens: a plain reinforced concrete (RC) specimen; and an identical RC specimen retrofitted with near surface mounted (NSM) carbon fibre reinforced polymer (CFRP) plates. Each specimen was subjected to two separate explosive loads at a standoff distance of 0.6m, with the aim of investigating the performances of both specimens within both their elastic and plastic response ranges. The first blast (Blast 1) and second blast (Blast 2) consisted of an equivalent TNT charge weight of 0.079kg and 2.09kg respectively. The elastic-range responses of both specimens after the small shot (Blast 1), such as acceleration and deflection were obtained and comparisons were made between the specimens. The plastic performances of both specimens, such as tension face scabbing, crack patterns, plastic hinges and permanent deflection, after the large shot (Blast 2) were also analysed and compared. A number of unique failures and behaviours of both specimens were observed, investigated and analyzed. The test results provide a vital direction in the development of an optimal retrofit in future research.