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This paper presents a numerical investigation on assessing whether the concrete damage plasticity (CDP) constitutive model can be used to simulate new ultra-high performance fibre reinforced concrete (UHP-FRC) material under impact loading rates at different damage stages. The performance of the numerical models is verified by comparing numerical results to the experimental data that were previously tested by the authors. This paper also presents experimental tests that aimed to characterize the strain rate effect on UHP-FRC. The numerical simulations have been performed using ABAQUS/Explicit. CDP parameters are identified based on impact test results of a control specimen. Subsequently, the predictive capability of calibrated model has been investigated by simulating two UHP-FRC plates with varied steel reinforcement ratios tested under repeated drop-weight impact loads. It has been found that compressive and tensile strength enhancement predicted using CEB-FIP Model Code (1990) fits well with test results of the strain rate effect on UHP-FRC material. The numerical results demonstrate the feasibility of the CDP constitutive model for analyzing UHP-FRC under dynamic loading rates. Computed responses are sensitive to CDP parameters related to the tension, fracture energy, and plastic volumetric change. The effect of tensile strain hardening response could be ignored in the nonlinear finite element (FE) analysis of UHP-FRC materials with low strain-hardening behaviour. [ABSTRACT FROM AUTHOR]

An experimental investigation has been conducted to assess the damage control properties of ultra-high performance fiber reinforced concrete (UHP-FRC) in comparison to traditional concrete. Five identical reinforced concrete (RC) plates, with the exception of concrete material, are damaged gradually using repeated impact technique. Damage progression has been evaluated stepwise based on the change in dynamic parameters and validated by visual inspection, midpoint residual displacement and successive number of impact tests to each specimen. Test results showed that UHP-FRC exhibits superior damage characteristics. The damage rate of UHP-FRC materials are approximately in the range of 6–15% the damage rate of normal-strength concrete. [ABSTRACT FROM AUTHOR]

An experimental investigation has been conducted to determine the effects of strain rate on fiber-reinforced cementitious composite (FRCC) matrixes. Compressive strength, modulus of elasticity, and flexural tensile strength are investigated under various strain rates ranging from the static to the seismic and/or impact level. Three different matrixes with compressive strengths ranging from 80 to 130 MPa (12 to 19 ksi) are investigated. The first matrix is without fiber, while the other two contain 2% straight steel fibers by volume. The tests are carried out according to ASTM standards. The dynamic increase factor (DIF) formulation recommended by the European CEB-fib is described. Experimental results showed that the rate sensitivity decreases with an increase in the matrix compressive strength. Additionally, it has been found that CEB-fib Model Code 2010 fits well with high-strength concrete. On the other hand, the CEB-fib Model (2010) overestimates both compressive and tensile strengths enhancement for FRCC with compressive strength over 110 MPa (16 ksi). [ABSTRACT FROM AUTHOR]