Issue 24

Y. Petrov et alii, Frattura ed Integrità Strutturale, 24 (2013) 112-118; DOI: 10.3221/IGF-ESIS.24.12 118 independent of the loading history, we can estimate and compare load-carrying capacity of materials in a wide range of loading rates. Three cases of the substitution effect were examined. In the first case, two different materials were compared. It is shown that the fibre reinforced concrete (CARDIFRC) has a lower dynamic strength for a higher static strength compared to the gabbro-diabase. In the second case, mortar and concrete were considered. It is shown that the substitution effect is also in this case. Moreover the difference between load-carrying capacity of concrete and mortar can depend on the elasticity of aggregate in concrete. In the third case, concrete with different water saturation was studied. It is shown that saturated concrete has a greater dynamic strength than dry concrete. Thus, humidity can increase the carrying capacity of concrete under dynamic loads, and vice verse under quasi-static loads. Thus, one of the central problems in testing of dynamic strength properties of rocks and concrete can be associated with measurements of the incubation time parameter. Studies of strain rate (loading rate) phenomenon provide an effective opportunity to examine the incubation stage of the fracture process that is important for predicting critical parameters of external action in a wide range of loading conditions. R EFERENCES [1] N.F. Morozov, Y.V. Petrov, Dynamics of fracture. Berlin-Heidelberg-New York: Springer-Velrag (2000). [2] A.M. Bragov, B.L. Karihaloo, Yu.V. Petrov, A.Yu. Konstantinov, D.A. Lamzin, A.K. Lomunov, I.V. Smirnov, J. of Applied Mechanics and Technical Physics, 53(6) (2012) 926. [3] A.M. Bragov, A.P. Bolshakov, N.N. Gerdyukov, A.K. Lomunov, S.A. Novikov, I.V. Sergeichev, In: International Conference "V Kharitonov thematic scientific reading" (Sarov, VNIIEF, 2003). [4] D.L. Grote, S.W. Park, M. Zhou, Int. J. of Impact Eng., 25 (2001) 869. [5] E. Cadoni, K. Labibes, C. Albertini, M. Berra, M. Giangrasso, Materials and structures, 34 (2001) 21. [6] Y.V. Petrov, A.A. Utkin, Material Science, 25 (1989) 153. [7] Y.V. Petrov, N.F. Morozov, ASME J. Appl. Mech., 61 (1994) 710. [8] Y.V. Petrov, Dokl. Phys., 49 (2004) 246. [9] Y.V. Petrov, B.L. Karihaloo, V.A. Bratov, A.M. Bragov, Int. J. of Engng. Sci., 61(1) (2012) 3. [10] A.C. Ross, E.Y. Thompson, J.W. ACI Mater. J., 86(5) (1989) 475. [11] P.H. Bischoff, S.H. Perry, Mater. Struct., 24 (1991) 425. [12] F. Akopov, A.M. Bragov, P. Demenko, L. Kruszka, A.K. Lomunov, V. Mineev, L.V. Sergeichev, J. de Physique IV, 110 (2003) 225. [13] T. Antoun, L. Seaman, D.R. Curran, G.I. Kanel, S.V. Razorenov, A.V. Utkin, Spall Fracture. Springer-Verlag New York (2003). [14] S.D.P. Benson, B.L. Karihaloo, Magazine Concrete Research, 57 (2005) 347. [15] V. Bratov, N. Morozov, Y. Petrov. Dynamic Strength of Continuum. St.-Petersburg University Press (2009). [16] T. Rodriguez, C. Navarro, V. Sanchez-Galvez, Journal de Physique IV, 4(C8) (1994) 101. [17] A.M. Bragov, B.L. Karihaloo, A.Yu. Konstantinov, D.A. Lamzin, A.K. Lomunov, Bulletin of Nizhny Novgorod University N. Lobachevsky, 4 (2011) 123. (in Russian)