... [4] Harsh S. et al. (1990) ACI Materials Journal, 87: 508 516. [5] Toutlemonde F., Gary G. in Dynamic Behavior of Concrete and Seismic Engineering, ISTE, (2009), 1 54. [6] Cotsovos DM, Pavlovic MN (2008) Int. J. of Impact... more
... [4] Harsh S. et al. (1990) ACI Materials Journal, 87: 508 516. [5] Toutlemonde F., Gary G. in Dynamic Behavior of Concrete and Seismic Engineering, ISTE, (2009), 1 54. [6] Cotsovos DM, Pavlovic MN (2008) Int. J. of Impact Engineering, 35: 319335. ...
Innovative particle-reinforced materials made of alumina particles and cement-based matrix were designed, manufactured and tested to evaluate the potential use of ceramic aggregates in concretes. These particle-reinforced composites were... more
Innovative particle-reinforced materials made of alumina particles and cement-based matrix were designed, manufactured and tested to evaluate the potential use of ceramic aggregates in concretes. These particle-reinforced composites were tested in three-point bending and uniaxial compression conditions to determine the influence of the shape and size of the ceramic inclusions, and the addition of silica fume on the mechanical properties.
ABSTRACT Dynamic tensile tests based on the so-called spalling technique may be conducted to characterize the tensile strength and the cracking density of concretes under strain-rates in the range of 30/s to 150/s. Based on this... more
ABSTRACT Dynamic tensile tests based on the so-called spalling technique may be conducted to characterize the tensile strength and the cracking density of concretes under strain-rates in the range of 30/s to 150/s. Based on this technique, a series of experiments have been performed in LEM3 laboratory by using an instrumentation including a laser interferometer directed toward the rear face of the sample and strain-gauges on the specimen. In the present work, a series of computations of spalling tests have been conducted with the Mazars damage model. First, the loading-rate sensitivity has been identified from spalling tests to take account in the modelling of the increase of strength with strain-rate. Next, a series of numerical simulations have been performed considering various mesh sizes and by using or not the Hillerborg regularization method. Finally the ability of the Mazars model for predicting the post-peak behaviour of concrete in spalling tests has been assessed by comparing the numerous experimental measurements to numerical data.
ABSTRACT To characterize the penetration resistance of a ceramic target during impact, it is necessary to take into consideration the mechanical behaviour of the fragmented ceramic. In the present work, a series of numerical simulations... more
ABSTRACT To characterize the penetration resistance of a ceramic target during impact, it is necessary to take into consideration the mechanical behaviour of the fragmented ceramic. In the present work, a series of numerical simulations have been performed to design an experimental configuration named the “normal impact test”. The aim of this configuration is to generate a strong fragmentation of the ceramic tile and to prevent any ejection of debris in order to analyse the fragmentation properties of the impacted ceramic. An anisotropic damage model has been used to perform these computations. The Weibull parameters that constitute input data of this model have been identified from four-point flexural tests performed on the so-called Hexoloy® silicon carbide. Finally, the numerical predictions are compared to the failure pattern of the fragmented ceramic.
In the present work, dynamic tensile strength of concrete is experimentally investigated by means of spalling tests. Based on extensive numerical simulations, the paper presents several advances to improve the processing of spalling... more
In the present work, dynamic tensile strength of concrete is experimentally investigated by means of spalling tests. Based on extensive numerical simulations, the paper presents several advances to improve the processing of spalling tests. The striker is designed to get a more uniform tensile stress field in the specimen. Three methods proposed in the literature to deduce the dynamic strength of the specimen are discussed as well as the use of strain gauges and a laser extensometer. The experimental method is applied to process data of several tests performed on wet micro-concrete at strain rates varying from 30 to 150/s. A significant increase of the dynamic tensile strength with strain-rate is observed and compared with data of the literature. In addition, post-mortem studies of specimens are carried to improve the analysis of damage during spalling tests.
ABSTRACT SUMMARY The aim of this study is to numerically model the fracture system at percussive drilling. Because of the complex behavior of rock materials, a continuum approach is employed relying upon a plasticity model with yield... more