Drop-Weight Impact Test for Fibre Reinforced Concrete: Analysis of Test Configuration

Impact resistance represents a key property of Fibre Reinforced Concrete (FRC). Recently, the authors proposed a repeated drop-weight test for FRC impact characterization that, among other advantages, is able to distinguish the contribution of different types and dosages of fibres both at cracking and in cracked state. The impacts are applied on a simply supported notched prism of 150 × 150 × 300 mm, being the adopted span length 240 mm, the notch depth 25 mm and the projectile mass 5 kg. An experimental and numerical parametrical study was carried out in order to analyse the effect of the specimen geometry on impact test results. The span length (240, 350 and 500 mm), the notch depth (10, 25 and 50 mm), the specimen width (70, 100 and 150 mm), and the projectile mass (5, 10 and 20 kg) were considered as variables. The numerical model was developed to analyse the stress distribution before the first crack appears (elastic behaviour). In order to corroborate the numerical model, the impact load was measured in some tests with a dynamic load cell. Numerical results concerning the effects of the above-mentioned variables on impact response are presented.