Mechanical Characteristics of Tunnel Concrete Lining Made with Dredged Sediment Subjected to High Temperatures

The development of dredged sediment (DS) valorization sectors in the port of Oran is a necessity to address the major environmental problem caused by their dumping at sea. This experimental study was conducted to study the influence of DSs on the behavior of concrete under extreme temperature conditions for a precise application: The tunnel concrete lining. To this end, two concretes were manufactured; C1 concrete manufactured with terrestrial granulates and C2 concrete with DSs. The influence of the replacement of the fine sand by DS on the compressive strength under normal conditions at 20 ℃ (Rc₂₀) and the residual compressive strengths (Rrc) after heating at temperatures of 150 ℃, 350 ℃, E and 600 ℃ and cooling in air and in water has been studied. The results showed the beneficial effect of the substitution of 25% fine sand by DS on the compressive strength (Rc₂₀) of C2 concrete as it has been slightly improved at 60 and 90 days (at 90 days: 56.2 MPa instead 49 MPa). The effects of high temperatures on the residual compressive strengths Rrc of the concrete are more pronounced when the concrete is subjected to thermal shock in water than in air.