Mechanical properties and impact resistance of a high-strength lightweight concrete incorporating prickly pear fibres

摘要

The aim of this work is to develop, for structural elements, an eco-lightweight concrete with high resistance incorporating prickly pear fibres. And to evaluate its physico-mechanical properties and impact resistance. Concrete is developed by introducing up to 15 kg/m(3) of prickly pear fibres in a formulation of ultra high performance concrete based on dune sand. The study is projected, firstly to investigate the physical, mechanical and thermal characteristics of the elaborated concrete, and secondly to determine the impact resistance of the developed concrete. Findings indicate that a flexural strength of 14 MPa, a compressive strength of 50 MPa and a specific resistance of 30 kPa/(kg/m(3)) could be obtained, according to the amount of prickly pear fibre used in concrete. Thermal conductivity is until 42% lower than fibre-free concrete. The use of prickly pear fibre increases the toughness of the concrete and gives it high speed impact resistance. Indeed, tests have shown that the penetration depth of the projectile decreases with the increase in the amount of fibre, and that the diameter of the crater is smaller than that obtained with ultra-high performance concrete. (C) 2020 Elsevier Ltd. All rights reserved.