Dynamic fracture investigations of ultra-high performance concrete by spalling tests. (15th December 2019)

• Record Type: Journal Article
• Authors: Khosravani, Mohammad Reza; Wagner, Peter; Fröhlich, Dirk; Weinberg, Kerstin
• Is Part Of: Engineering structures. Volume 201(2019)
• Publication Date: 2019-12-15
• Subjects: Dynamic strength -- Spalling test -- Fracture energy -- Dynamic loading -- UHPC; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2019.109844
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Fracture behavior of ultra-high performance concrete (UHPC) material under dynamic loading regime is studied. Split Hopkinson pressure bar was modified to perform a series of spalling tests on cylindrical UHPC specimens. Elastic modulus, tensile strength and fracture energy of UHPC material are determined under rate of loading. There is a good agreement between experimental results and numerical verification of the spalling tests. Abstract: Ultra-High Performance Concrete (UHPC) is an innovative cement based material with superior strength for engineering structures. The mechanical properties of the cementitious composite depend on its exact composition and need to be determined experimentally. Whereas several standard tests for the static loading regime exist, dynamic data such as tensile strength and failure load are difficult to measure. This contribution presents an experimental method to identify the material properties under impact loading. By means of a modified Hopkinson pressure bar, cylindrical UHPC specimens of different compositions without fiber are examined in strain rates of approximately 30 s - 1 . Assuming uniaxial wave propagation, the resulting stress states are analyzed and the specimens' dynamic elastic modulus, tensile strength and specific fracture energy are determined. Numerical fracture simulations in the sense of an inverse analysis prove the experimental approach valid. The agreement between both, experimental observations and numerical results, show that the obtained parameter are reliable and suitable for predictive simulations.