Tensile Strength versus Toughness of Cement-Based Materials against High-Velocity Projectile Impact

摘要

This paper presents a laboratory experimental study on the effect of tensile strength and toughness on the resistance of cement-based materials to high-velocity projectile impact. Three types of cement-based materials with similar compressive strength but different tensile strengths and toughnesses were examined in terms of the penetration depth, crater diameter, and crack propagation in specimens subjected to impact of ogive-nosed projectile with a diameter of 13.35 mm and a mass of 19 grams traveling at velocities of about 650 m/s. The materials evaluated include: (I) a plain high-strength concrete (HSC) with low tensile strength and toughness, (ii) a fiber-reinforced concrete (FRHSC) with high toughness but similar flexural tensile strength as the HSC, and (III) a polymer cement composite (PCC) with high flexural tensile strength but low toughness. The PCC was developed from a combination of inorganic cements with water-soluble polymers, and It had a 28-day flexural tensile strength of 25 MPa. Results suggest that the toughness was a more important parameter that contributes to the impact resistance of the cement-based materials. Increasing the tensile strength alone, however, did not seem to contribute to the impact resistance of the cement-based materials.