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

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

Trabelsi, Abderraouf / Kammoun, Zied

Highlights • Using prickly pear fibres, a reduction of up to 30% of the density and 50% of the thermal conductivity is obtained. • An improvement in flexural strength at 28 days of up to 35% compared to the free-fibres composition. • The obtained value for compressive strength varies between 41 MPa and 59 MPa. • Higher the used amount of fibre, smaller the obtained projectile penetration. • The addition of prickly pear fibres to the UHPC reduces the crater diameter.

Abstract 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.