Blast and Impact Loading and Response of Structures
Designers are looking to use high strength concrete, ranging from 12 ksi to 17 ksi or more, to utilize space and cost savings for blast resistant building designs. Normal strength concrete between 4 ksi and 6 ksi has typically been used in recent designs by the Corps of Engineers Protective Design Center. A set of experiments were conducted using ERDC’s small scale static water chamber to compare the static response of reinforced normal and high strength concrete panels. The test specimens were small scale 33.75 in. x 60 in. reinforced concrete panels that utilized the Unified Facilities Criteria (UFC) for hardened structures as guidelines for the reinforcing details. The two concrete strength mixes utilized were 4 ksi and 13 ksi concrete. Both simply supported and fixed supported boundary conditions were utilized in testing. These experiments served to compare the static resistance of reinforced normal strength and high strength concrete panels to quantify the resistance function increases that may exist. The static resistance of each panel can be placed in a Single-Degree-of-Freedom (SDOF) model to determine the potential dynamic response of the reinforced concrete panels. The results of the SDOF analysis were used to calibrate a fast running model that provided P-I curves for damage levels of low to severe damage to reinforced concrete panels tested in ERDC’s Blast Load Simulator (BLS). The BLS experiments provided comparisons of the two concrete strength panels under multiple dynamic loadings and provide validation of the SDOF analysis. The benefits of using high strength concrete will be discussed in the context of the static resistance function, associated SDOF model, and benefits under dynamic loading conditions.