It is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0% plastic. Laboratory tests on the Standard compaction test, Unconfined compression test (UCS), and California bearing ratio (CBR) were conducted according to the American Society for Testing and Materials (ASTM). The results of the study reveal that there are significant improvements in the strength of weak soil stabilized with plastic waste strips. Accordingly, the Standard Proctor test shows that there is a small increment in the maximum dry density of the soil when it is mixed with plastic strips. The result from the CBR test shows that there is a significant increment of CBR value with the plastic strip content. The unconfined compressive strength test also shows that increasing the percentage of plastic strips from 0 to 0.4% resulted in increased strength of soil by 138% with 2 cm length plastic strips. Therefore, this study recommends the application of plastic strips for improvement of the strength of soft clay for subgrade construction in civil engineering practice as an alternative weak soil stabilization method.
Using the method of singular integral equations, the elastic-plastic problem for cracked Brazilian disk was solved. Based on the Dugdale model and deformation fracture criterion, the relationships between critical load, notch tip opening displacement and length of the plastic strips were established. Also, the comparison between the present solution for the finite domain and the known solution obtained for the semi-infinite notch in the elastic plane was performed.
In the article, the pure bending problem for strip (beam) with straight, perpendicular to its axis crack located in the zone of tensile stresses is investigated on the assumption of narrow plastic strips near crack tips. Using methods of the theory of functions of a complex variable and complex potentials, the problem is reduced to the several linear conjunction problems. The solutions of latter problems are ob-tained in the class of functions confined in the edges of plastic strips. Formulas for the calculation of their lengths are derived. Expressions for the determination of crack tip opening values are written. Numerical analysis of the problem is performed.
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Because of clear trend in the world to design lighter plastic products, the phenomenon of creep buckling of visco-elastic solids becomes increasingly important. This paper reports the intermediate results of the research project on loading capability and buckling of plastic containers, carried out in the Laboratory of Mehanical Raliability (LMB) of TU Delft. Based on the earlier development non-linear visco-electricity model for engineering plastics, the FE simulation of the delayed in time buckling of plastic strips have been performed as a first step toward the understanding and predicting creep-buckling behaviour of plastic carriers.
PL
Wobec oczywistego światowego trendu w kierunku projektowania produktów z lekkich tworzyw, coraz bardziej istotne staje sie zjawisko pełzającego wyboczenia brył plastykowych o właściwościach lepko-sprężystych. Niniejsza praca przedstawia wyniki etapu badań, prowadzonych w Laboratorium Niezawodności Mechanicznej Politechniki w Delft (Holandia), nad obciążalnością i wyboczeniam pojemników plastykowych. Posługując się opracowanym wcześniej nieliniowym modelem lepkościowo-sprężystym dla plastyków konstrukcyjnych, wykonano symulację metodą elementów skończonych zjawiska opóźnionego wyboczenia pasków plastykowych. Stanowiło to pierwszy krok do zrozumienia i przewidywania zjawiska pełzającego wyboczenia nośników plastykowych.
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