Investigation of ultra-high performance concrete slab and normal strength concrete slab under contact explosion

Dynamic performance of concrete structures under blast loading conditions is a topic of importance as such load generates severe structural damage including flexural damage, shear damage and concrete spall damage which may impose threats to the personnel and instruments shielded by the reinforced concrete structure. To mitigate blast effects on civil structures, a new kind of concrete material named Ultra-High-Performance-Concrete (UHPC) is now widely studied and applied. UHPC material is known for its high compressive and tensile strength, large energy absorption capacity as well as good workability and anti-abrasion ability. In a previous study, the performance of UHPC slab under blast loads had been investigated through free air explosion tests. The blast resistance capacity of UHPC had been demonstrated through comparison with normal strength concrete. In the present study, the dynamic performance of UHPC slab under contact charge explosion is experimentally studied and compared with normal strength concrete slab under the same loading scenario. Numerical models are established to reproduce both the previous free air explosion tests and the current contact explosion tests. In particular, finite element model is established to simulate the free air explosion test, and coupled smoothed particle hydrodynamics (SPH) method and finite element method is utilized to simulate the contact blast tests. Numerical results are compared with the experimental observations, and the feasibility and accuracy of the numerical model are validated.