: 127-132
Lviv Polytechnic National University, Department of construction production
Lviv Polytechnic National University, Department of Building Production
Lviv Polytechnic National University, Department of Building Production

The application of engineering cementitious composites (ECC) – a specially developed class of cement-based material reinforced with fibers – allows to enhance the loading capacity, stability under static and dynamic influences, as well as durability of building structures due to controlled cracking process. The design of engineering cementitious composites is based on the concept of micromechanics, which includes the strength and energy criteria of deformation strengthening throughout the wide range from the macro- to the nanostructural level. This concept based on the ability of the dispersed fibers to perceive the load and absorb energy. However, the high volume of cementitious materials in ECC, often up to 70 %, results in a large drying shrinkage, limitation on dimensional stability and negative effects on material cost. The flowability and strength of engineered cementitious composites based on binary and ternary systems of binder materials with different content of dispersed fibers are researched. It is established that an increasing of fiber amount leads to a significant reduction in the flowability of cementitious composites, so the fiber content of 1.5–2 % is optimal. When the disperse fibers are introduced, part of it works on tension, and some of it prevents particle displacement, ensuring the integrity of the system under the action of external loading. It is shown that the combination of fly ash and ultrafine mineral additives with high surface energy in the ternary system of binder materials, the use of polycarboxylate superplasticizer, as well as reinforcement of the engineered composites structure with dispersed fibers in optimum amounts contribute to their mechanical properties both at an early and later hardening period compared to composites based on binary system of binder materials. With the use of a complex of mineral additives that provides a dense packing of particles, filling space between cement grains, an early pozzolanic reaction, obtaining of additional hydration products, the coefficient of crack resistance increases to 0.227-0.240 compared with 0.216 for the EСC based on the binary system of binder materials.

1. Dvorkin L. Y., Babych Y. M., Zhytkovsky V. V., Bordyuzhenko O. M., Filipchuk S. V., Kochkarov D. V., Kovalyk I. V., Kovalchuk T. V., Skrypnyk M. M. (2017) Vysokomitsni shvydkotverdnuchi betony ta fibrobetony. [High-strength rapid hardening concretes and fiber reinforced concretes]. Rivne, NUVGP, 331 p. [in Ukrainian]. 2. Sanytsky M., Marushchak U., I. Kirakevych, M. Stechyshyn. (2015) Vysokomitsni samoushchilniuvalni betony na osnovi dyspersno-armovanykh cementuuchyh system. [High-strength self-compacting concrete based on dispersion-reinforced cementing systems]. Budivelni materialy ta vyroby. № 1. S. 10-14. [in Ukrainian]. 3. Solodkyy S. Y., Kahanov V. O., Hornikovska I. B., Turba Yu. V. (2015) Doslidzhennia trishchynostiykosti vazhkyh betoniv ta pinobetoniv, armovanyh polipropilenovoyu fibroyu dlia dorozhnioho budivnytstva. [A study of the cracking properties of normal weight concrete and foam concrete reinforced with polypropylene fiber for road construction.]. Vostochno-Yevropeyskiy zhurnal peredovyh tehnologiy – Eastern-European Journal of Enterprise Technologies. no 4/5 (76), pp. 40–46. [in Ukrainian]. 4. Suhanov V. G., Vyrovoy V. N., Korobko O. A. (2016) Struktura materiala v structure konstruktsui. [Structure of material in construction structure]. Odessa, Poligraf, 244 p. [in Russian]. 5. Yu К., Jiangtao Y., Dai J.-G., Lu Z.-D., Shah S. P. (2018) Development of ultra-high performance engineered cementitious composites using polyethylene (PE) fibers. Construction and Building Materials. no 158, pp. 217–227. 6. Zhang J., Gong C., Guo Z., Zhang М. (2009) Engineered cementitious composite with characteristic of low drying shrinkage. Cement and Concrete Research. no 39, pp. 303–312. 7. Li V. C. On Engineered Cementitious Composites (ECC). A review of the material and its applications. Journal of Advanced Concrete Technology. 2003, Vol. 1, No. 3, pp. 215–230. 8. Marushchak U., Sanytsky M., Sydor N. (2017) Design of rapid hardening engineered cementitious composites for sustainable construction. SSP – Journal of Civil Engineering. Vol. 12, Issue 2, pp. 107–112. 9. Sakulich A. R., Li V. C. (2011) Nanoscale characterization of engineered cementitious composites (ECC). Cement and Concrete Research. no 41, pp. 169–175. 10. Derevyanko V. N., Shapovalova O. V., Kondratieva N. V., Maksimenko A. A. (2015) Dispersnoye armirovaniye – sposob povysheniya prochnosti izdeliy. [Disperse reinforcement is method of strength increasing of wares]. Visnyk Prydniprovskoi derzhavnoi akademii budivnytstva ta arhitektury – Pridneprovs’k State Academy of Civil engineering and Architecture, no 3 (204), pp. 10–19. [in Russian]. 11. Marushchak U., Sanytsky M., Mazurak T., Olevych Yu. (2016) Research of nanomodified Portland cement compositions with high early age strength. Eastern-European Journal of Enterprise Technologies. no 6/6 (84), pp. 50–57.