5.1 Introduction
107
coarse aggregates mixed into SFRHSC, especially when the compressive strength is
larger than 100 MPa. In such a way, the anti-penetration capacity of coarse aggregates is neglected. Besides, the casting and curing of ultra-high strength concrete
(>150 MPa, e.g. RPC) needs high temperature (90–400 °C) and sufficient pressure
to expel the excess liquids and air from the fresh mixture, which prohibits its largescale construction applications. Secondly, the projectile penetration efficiency as well
as the damages of both projectile and concrete target are dependent on the striking
velocity to a great extent. Most of the existing projectile penetration tests (Dancygier
and Yankelevsky 1996; Dancygier 1998; O’Neil et al. 1999; Luo et al. 2000; Liu et al.
2002; Zhang et al. 2005, 2007; Dancygier et al. 2007; Tai 2009) conducted by weapon
designer or protective engineers were mainly aiming to the conventional earth penetration weapons, of which the striking velocity were relatively low (<700 m/s). While
for the high-speed advanced earth penetration weapons (the striking velocity could
reach 1500 m/s), UHPCC is considered as the most proper construction materials
for protective structures, especially for the military fortifications. However, the highspeed projectile penetration resistance of UHPCC as well as the influential factors
are still not clear, and thus the related projectile penetration tests with broad striking
velocity are urgently needed.
In Sect. 5.2, UHPCC with the additions of both steel fibers and basalt coarse aggregates, was prepared under ambient temperature and pressure by State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute
of Building Science. For the applications of UHPCC in the anti-strike protective
structures, the projectile penetration tests on UHPCC target was carried out with the
striking velocities from 510 to 1320 m/s. The damages of both UHPCC target (impact
crater dimensions, DOP) and the projectile (structural destruction and ballistic trajectory deviation), as well as the parametric influences (compressive strength of the
target, the projectile striking kinetic energy, fiber mixing fraction and the coarse
aggregates) were examined and discussed.
In Sect. 5.3, the corundum coarse aggregates (compressive strength exceeds
2000 MPa, Young’s modulus 400 GPa, density 4000 kg/m
3 , Mohs hardness 9.5,
main chemical component is Al 2 O 3 ) were further adopted and the corundum aggregated UHP-SFRC (UHP-CASFRC) was prepared. Based on a series of high-speed
(510–850 m/s) projectile striking tests, the influences of the strength (hardness), size
and volumetric ratio of coarse aggregate, incident velocity of the projectile as well as
the repeated strikes on the impact resistance of UHP-CASFRC target were assessed.
The outstanding impact resistance of UHP-CASFRC against the projectile penetration was verified. Then, by examining the structural integrity of the projectiles, the
optimal corundum aggregate size of UHP-CASFRC target was suggested for the
constructions of protective structures.
In Sect. 5.4, the corresponding numerical simulations aiming to examine the
influences of coarse aggregates on the penetration resistance of coarse aggregated
UHPCC were performed. Firstly, the generation algorithms of three-dimensional
(3D) mesoscopic concrete models with the randomly distributed sphere and convex
107
coarse aggregates mixed into SFRHSC, especially when the compressive strength is
larger than 100 MPa. In such a way, the anti-penetration capacity of coarse aggregates is neglected. Besides, the casting and curing of ultra-high strength concrete
(>150 MPa, e.g. RPC) needs high temperature (90–400 °C) and sufficient pressure
to expel the excess liquids and air from the fresh mixture, which prohibits its largescale construction applications. Secondly, the projectile penetration efficiency as well
as the damages of both projectile and concrete target are dependent on the striking
velocity to a great extent. Most of the existing projectile penetration tests (Dancygier
and Yankelevsky 1996; Dancygier 1998; O’Neil et al. 1999; Luo et al. 2000; Liu et al.
2002; Zhang et al. 2005, 2007; Dancygier et al. 2007; Tai 2009) conducted by weapon
designer or protective engineers were mainly aiming to the conventional earth penetration weapons, of which the striking velocity were relatively low (<700 m/s). While
for the high-speed advanced earth penetration weapons (the striking velocity could
reach 1500 m/s), UHPCC is considered as the most proper construction materials
for protective structures, especially for the military fortifications. However, the highspeed projectile penetration resistance of UHPCC as well as the influential factors
are still not clear, and thus the related projectile penetration tests with broad striking
velocity are urgently needed.
In Sect. 5.2, UHPCC with the additions of both steel fibers and basalt coarse aggregates, was prepared under ambient temperature and pressure by State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute
of Building Science. For the applications of UHPCC in the anti-strike protective
structures, the projectile penetration tests on UHPCC target was carried out with the
striking velocities from 510 to 1320 m/s. The damages of both UHPCC target (impact
crater dimensions, DOP) and the projectile (structural destruction and ballistic trajectory deviation), as well as the parametric influences (compressive strength of the
target, the projectile striking kinetic energy, fiber mixing fraction and the coarse
aggregates) were examined and discussed.
In Sect. 5.3, the corundum coarse aggregates (compressive strength exceeds
2000 MPa, Young’s modulus 400 GPa, density 4000 kg/m
3 , Mohs hardness 9.5,
main chemical component is Al 2 O 3 ) were further adopted and the corundum aggregated UHP-SFRC (UHP-CASFRC) was prepared. Based on a series of high-speed
(510–850 m/s) projectile striking tests, the influences of the strength (hardness), size
and volumetric ratio of coarse aggregate, incident velocity of the projectile as well as
the repeated strikes on the impact resistance of UHP-CASFRC target were assessed.
The outstanding impact resistance of UHP-CASFRC against the projectile penetration was verified. Then, by examining the structural integrity of the projectiles, the
optimal corundum aggregate size of UHP-CASFRC target was suggested for the
constructions of protective structures.
In Sect. 5.4, the corresponding numerical simulations aiming to examine the
influences of coarse aggregates on the penetration resistance of coarse aggregated
UHPCC were performed. Firstly, the generation algorithms of three-dimensional
(3D) mesoscopic concrete models with the randomly distributed sphere and convex