PSI - Issue 81

Olena Romashko-Maistruk et al. / Procedia Structural Integrity 81 (2026) 269–275

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Based on expressions (10 )…(1 2), it is quite easy to predict the deformability of compressed concrete under the action of long term loads: k k l l c lc с / 1 1,       . (13) The range of changes in the level of deformability of compressed concrete for its various classes and strain rates under the action of long-term loads is shown in Fig. 5.

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

concrete( ε c1,l / ε c1 )

Level of deformability of compressed

0

20

40

60

80

100

120

140

Concrete class (f ck,cube , MPa)

10 1 10    s   ;

Fig. 5. The range of changes in the level of deformability of compressed concrete under prolonged loads for its different classes at strain rates: -

8 1 10    s   ; -

6 1 10    s   .

-

The graphs in Fig. 2…5 confirm that using the elastic -plastic coefficient of concrete, it is quite simple to predict its deformability at any strain rate of concrete. 5. Conclusions The proposed express methodology for predicting the main physical and mechanical characteristics of compressed concrete allows for modelling the actual deformation diagram of compressed concrete at any strain rate. Also, to predict not the conditional modulus of elasticity of concrete, but the secant modulus of deformation of concrete at any speed and arbitrary load level. Therefore, the results of these studies can be used in the development of a universal methodology for calculating concrete and reinforced concrete elements and structures under the action of any loads. References Awad, M.E., Hilsdorf, H.K., 1971. Strength and Deformation Characteristics of Plain Concrete Subjected to High Repeated and Sustained Loads. Structural Research Series 372. Univ. of Illinois at Urbana-Champaign, pp. 266. https://www.ideals.illinois.edu/items/14427. Bischoff, P.H., Perry, S.H., 1991. Compressive behaviour of concrete at high strain rates. Materials and Structures 24(6), 425-450. https://link.springer.com/article/10.1007/BF02472016. CEB-FIP, 1991. Model Code 1990. Design Code. Comité Euro - International du Béton, Lausanne, pp. 437. Cowell, W.L., 1966. Dynamic properties of plain Portland cement concrete. Technical Report No. R447, DASA 130181. US Naval Civil Engineering Laboratory, Port Hueneme, California, pp. 51. https://apps.dtic.mil/sti/trecms/pdf/AD0635055.pdf. Dejian, S., Lu, X., 2008. Experimental study on dynamic compressive properties of microconcrete under different strain rate. In Proceedings of the 14th World Conference on Earthquake Engineering, Beijing, China. https://www.iitk.ac.in/nicee/wcee/article/14_12-03-0098.PDF. Dilger, W.H., Koch, R., Kowalczyk, R., 1984. Ductility of plain and confined concrete under different strain rates. ACI Journal 81(1), 73-81. https://doi.org/10.14359/10649. Fib, 2012. Model Code 2010. Final draft - Volume 1, fib Bulletin 65, pp. 357. Fujikake, K., Mizuno, J., Suzuki, A., Ohno, T., Nonak, T., 1998. Dynamic strain softening of concrete in compression under rapid loading. WIT Transactions on the Built Environment: Structures under Shock & Impact 32, 481-491. Graf, O., Brenner, E., 1937. Versuche mit Betonkörpern, die einer dauernd wirkenden Druckbelastu ng ausgesetzt waren. Bauingenieur, 19/20, 237-270. Grote, D.L., Park, S.W., Zhou, M., 2001. Dynamic behavior of concrete at high strain-rates and pressures: I. Experimental characterization. International Journal of Impact Engineering 25, 869-886. https://doi.org/10.1016/S0734-743X(01)00020-3. Hjorth, O., 1976. Ein Beitrag zur Frage der Festigkeiten und des Verbundverhaltens von Stahl und Beton bei hohen Dehnungsgeschwindigkeiten: Doktoral Thesis. TU Braunschweig, pp. 188.