Change of Strength of Brittle Building Materials under High Strain and Stress Rates

Resumo

Experimental results on assessing the effects of strain and stress rates on the strength of brittle building materials such as fine-grain concretes and ceramic brick are presented. Specimens of these materials were dynamically tested using the Kolsky method and its modification, the Brazilian test (or splitting test). Were obtained strain rates up to 2.5 × 10³ s⁻¹ at compression and the stress rates up to 3 × 10³ GPa/s at tension. As a result of the experiments, values of the Dynamic Increase Factor (DIF) were determined for these the materials studied. Their curves as a function of strain and stress rates were constructed. The experimental data is compared with the theoretically obtained values of DIF as a function of strain rate available in the literature for fine-grain and fiber-reinforced concretes.