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Highlights • The loading rate dependent mechanical properties of UHP-FRC is investigated. • Influences of compressive strength and fibre content on mechanical properties of UHP-FRC are addressed. • Increasing fibre content (1.0–3.0%) enhances tensile properties and post-peak ductility. • Increasing fibre content (1.0–3.0%) has limited effect on compression properties. • Dynamic enhancement in flexural strength is inversely proportional to fibre content. Abstract This research investigates the loading rate dependent compressive strength, elastic modulus, and flexural strength of ultra-high performance fibre reinforced concrete (UHP-FRC). This investigation is motivated by the lack of dynamic increase factor (DIF) models that can be used in dynamic numerical analysis of UHP-FRC. Five UHP-FRC series incorporating three different matrix strength (110, 130, 150 MPa); and three different fibre volume content (1.0, 2.0, and 3.0%) are tested at six different strain rates ranging from the quasi-static (10−6 s−1) to impact level (5 s−1). Experimental results have revealed that increasing fibre volume content from 1.0 to 3.0% significantly increases the quasi-static tensile properties and post-peak ductility, however, it has a limited effect on quasi-static compression properties; the dynamic enhancement in the flexural (tensile) strength is inversely proportional to the fibre content. On the other hand, the effect of fibre content on the enhancement of compressive strength and elastic modulus is insignificant. [ABSTRACT FROM AUTHOR]

An experimental investigation has been conducted to collect fundamental data and to develop more understanding of the effect of steel reinforcement distribution on the dynamic response of reinforced concrete plates. Five high strength concrete (HSC) plates are tested using free-fall low-velocity impact technique. A total of 10 impact tests are conducted, including two tests on each specimen. The impact loads are applied at the mid-point of the HSC plates by dropping a 475 kg steel weight from a constant height of 4.15 m. Two parameters are investigated namely: the main bottom steel reinforcement ratio (1.0, 2.0, and 3.0%); and the steel reinforcement arrangement (single or doubly reinforced plates). The top reinforcement of all doubly reinforced plates is kept constant as shrinkage reinforcement of 10 mm diameter spaced at 210 mm. The experimental results are evaluated focusing on the impact force characteristics and the impact behaviors of reinforced concrete plates. The test program was successful in providing a simple method for validating impact test setup using impulse–momentum theorem. Results showed that the change of reinforcement ratio and/or reinforcement arrangement has no significant effect on impulse and absorbed energy values for same impact loading condition. Additionally crack pattern and failure mode are found to be more dependent on the reinforcement arrangement rather than reinforcement ratio. [ABSTRACT FROM AUTHOR]