Visnyk LNAU: Architecture and Farm Building 2016 №17: 66-71


V. Bilozir, PhD.,
V. Bilozir, student
Lviv National Agrarian University


Experimental data on deformability and strength of rings cut from used PET bottles show that the average elastic modulus of the material  temporary resistance  To the level of tensions 80 MPa PET works practically resiliently. According to Hooke's law, such a level of stress will correspond to a relative deformation of 0.0258. These deformations are approximately the same as the limits for reinforcing steel, established by European standards for the design of reinforced concrete structures. The maximum deformations that correspond to the temporary resistance of the PET are very significant, so in the bending elements will not be achieved. Thus, as a calculation for a PET fibris, one can accept a two-line deformation diagram (Prandtl diagram) with a horizontal line starting at point for which the strain  corresponds to the relative deformations .

Theoretically founded the length of a fiber that would anchoring by a quarter of  length for different classes of concrete at the strength of the fibers . A quarter of the length of the fibers is the mean value of the length of the fiber gain that falls to the critical fracture front.

Calculations have shown, for example, that for a concrete grade C20 / 25, reinforced with PET- fibers of 35 x 2 x 0.2 mm, concrete and fiber-reinforced  concrete patterns will have the same strength when μfv = 0,022 (2,2%).

Theoretically reasonable question of designation geometrical sizes of PET fiber. The refinement in the proposed analytical apparatus can be made after experimental studies of the bonding of PET-fibers with concrete and refinement of the coefficient of adhesion η.

It is necessary to experimentally investigate the influence of the percentage of fiber reinforcement on the bending strength of PET- fiber reinforced concrete, which will prove minimum reinforcement percent by volume and introduce the necessary clarifications in formulas.

Key words

polyethylene terephthalate, PET-bottles recycling, PET-fiber, fiber-reinforced concrete

Full text



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