Chapter 3
Dynamic Tensile Mechanical Properties
of UHPCC
3.1 Introduction
Spallation is a specific kind of fracture in solids, which is developed by tensile stress
pulses produced by the reflection of compression waves at the interfaces adjacent
to low impedance media. For example, in case of the projectile impacting on a
target, the contact detonation of high explosives on the target or the sudden deposition of an intense pulse of energy on the target surface, the intensive compressive
waves are generated and propagate through the structures. These compressive waves
are reflected back at the free surface of structures and turn to the tensile waves,
leading to the fracture of the concrete in the form of spallation due to its low tensile
strength (Goldsmith et al. 1996; Watson and Sanderson 1979; Malvar and Crawford 1998). The study of dynamic tensile (spalling) behavior of UHPCC can provide
helpful reference for exploring the dynamic mechanical properties and establishing
the constitutive model of UHPCC.
In the existing studies about the dynamic tensile properties of concrete materials, Brara et al. (Brara et al. 2001; Klepaczko and Brara 2001) developed an efficient experimental technique to investigate the dynamic tensile behavior of concrete
(45 MPa in compression) under the strain rates of 10 ~ 120 s
−1 and found the high
rate sensitivity of concrete strength in tension at high strain rates. Furthermore,
a local damage cumulative criterion which incorporated the loading rate sensitivity
was proposed and implemented in numerical analyses. By examining the strain wave
profiles in a polymer buffer bar behind the slender concrete bar specimen, Zhang et al.
(2009) proposed a new method to measure the dynamic spalling strength of C30,
C60 and C80 concrete. The experimental results showed that the dynamic spalling
strength is dependent on both the compressive strength of concrete and the strain rate.
Wang et al. (2012) evaluated the influence of steel fiber content (0, 0.75 and 1.5% by
volume) on the dynamic spalling strength of steel fiber reinforced normal strength
concrete (SFRC) with the compressive strength of 62.7 ~ 68.6 MPa at medium strain
rates (48.7–72.0 s
−1 ). It was concluded that SFRC is strain rate dependent, and the
volume fraction of fibers exerted a significant influence on the dynamic spalling
© Science Press 2021
Q. Fang et al., UHPCC Under Impact and Blast,
https://doi.org/10.1007/978-981-33-6842-2_3
55
Dynamic Tensile Mechanical Properties
of UHPCC
3.1 Introduction
Spallation is a specific kind of fracture in solids, which is developed by tensile stress
pulses produced by the reflection of compression waves at the interfaces adjacent
to low impedance media. For example, in case of the projectile impacting on a
target, the contact detonation of high explosives on the target or the sudden deposition of an intense pulse of energy on the target surface, the intensive compressive
waves are generated and propagate through the structures. These compressive waves
are reflected back at the free surface of structures and turn to the tensile waves,
leading to the fracture of the concrete in the form of spallation due to its low tensile
strength (Goldsmith et al. 1996; Watson and Sanderson 1979; Malvar and Crawford 1998). The study of dynamic tensile (spalling) behavior of UHPCC can provide
helpful reference for exploring the dynamic mechanical properties and establishing
the constitutive model of UHPCC.
In the existing studies about the dynamic tensile properties of concrete materials, Brara et al. (Brara et al. 2001; Klepaczko and Brara 2001) developed an efficient experimental technique to investigate the dynamic tensile behavior of concrete
(45 MPa in compression) under the strain rates of 10 ~ 120 s
−1 and found the high
rate sensitivity of concrete strength in tension at high strain rates. Furthermore,
a local damage cumulative criterion which incorporated the loading rate sensitivity
was proposed and implemented in numerical analyses. By examining the strain wave
profiles in a polymer buffer bar behind the slender concrete bar specimen, Zhang et al.
(2009) proposed a new method to measure the dynamic spalling strength of C30,
C60 and C80 concrete. The experimental results showed that the dynamic spalling
strength is dependent on both the compressive strength of concrete and the strain rate.
Wang et al. (2012) evaluated the influence of steel fiber content (0, 0.75 and 1.5% by
volume) on the dynamic spalling strength of steel fiber reinforced normal strength
concrete (SFRC) with the compressive strength of 62.7 ~ 68.6 MPa at medium strain
rates (48.7–72.0 s
−1 ). It was concluded that SFRC is strain rate dependent, and the
volume fraction of fibers exerted a significant influence on the dynamic spalling
© Science Press 2021
Q. Fang et al., UHPCC Under Impact and Blast,
https://doi.org/10.1007/978-981-33-6842-2_3
55