The performance and durability of polyethylene terephthalate and crumb rubber–modified road pavement surfaces

Abstract

This research investigates the influence of waste polymeric polyethylene terephthalate (PET) materials obtained from waste plastic bottles and crumb rubber (CR) obtained from used automobile tyres on the performance (Marshall stability, flow and compression) and durability (weathering) characteristics of road-paving material made from Trinidad Petroleum Bitumen and the world-renowned Trinidad Lake Asphalt. Apart from possibly serving as additives to improve performance, incorporating waste PET and CR in asphaltic road-paving materials also offers a viable means of alleviating health and environmental problems associated with the waste disposal of PET and CR. The results of the Marshall testing found that the optimum dosage for polymer modification was 1.0% and 5.0% for PET and CR polymers, respectively. In comparison with a Marshall stability value for the unmodified asphalt sample of 10.2 kN with a corresponding flow value of 3.1 mm, the 5% PET modified sample had a Marshall stability value of 10.2 kN with a flow value of 3.2 mm, while the CR modified sample recorded the highest Marshall stability value of 10.7 kN at corresponding flow value of 2.8 mm. An undesirable trend of the gradual increasing of the voids in mineral aggregate (VMA) with incremental increases in the % of added PET and CR was observed; however, for all the modified specimens with the exception of the 5% PET modified sample, the VMA fell within the acceptable range of between 14% and 20%. The results of accelerated weathering and compression testing demonstrated that both the 1% PET and the 5% CR-modified samples had higher durability and compressive strength characteristics than the unmodified samples. Compressive stress values for the polymer-modified specimens were in excess of 45% compared to the unmodified ones. The relevance of the values obtained in this study cannot be ignored as it provides practical and essential data, especially of the optimal dosages of PET and CR required for the enhancement of the mechanical and durability properties of the Trinidad road-paving materials while simultaneously providing an environmentally desirable and sustainable method for reusing these waste polymers. Commercial application of the optimum formulation can be immediately implemented.

Influence of the Chemical Composition of Kulantau Vermiculite on the Structure of Modified Bitumen Compositions

“…These disadvantages are eliminated by an innovative modifying additive-expanded Kulantau vermiculite, which is a complex modifier designed to improve the asphalt concrete mixture during its preparation. Several studies have evaluated the possibility of using residues to make asphalt mixtures [20][21][22][23][24][25][26][27].…”

“…These disadvantages are eliminated by an innovative modifying additive-expanded Kulantau vermiculite, which is a complex modifier designed to improve the asphalt concrete mixture during its preparation. Several studies have evaluated the possibility of using residues to make asphalt mixtures [20][21][22][23][24][25][26][27]. The spectra obtained through IR spectroscopy, following the methodology for conducting a comparative analysis of the chemical composition of compounds, were overlaid with scaling based on CH2 groups, with content independent of experimental conditions.…”

Waste materials in highway applications: An overview on generation and utilization implications on sustainability

“…Production of plastic containers from pellets is a quicker and much cheaper process compared to the recycling and reuse processes this brings about a continuous increase in the generation of PET (Hopewell et al, 2009;Thompson et al, 2009). The rising-rate at which these plastic wastes are disposed cause negative impacts such as visual pollution, flooding, endangerment of sea animals, and wildlife (Maharaj et al, 2019;Bamigboye et al, 2019) PET has also made grave economic impacts. A report by Weber and Kroll (2019) states that plastic waste results in damages to the marine ecosystem worth US$13 billion annually.…”

“…The Modulus of Resilience (M R ) decreased with increasing PET content due to the reduction of internal friction between particles. Maharaj et al (2019) reported on the durability and performance of road pavement surfacing with PET and Crumb rubber (CR). Marshal mix results showed that the optimum content of PET and CR polymer is 1% and 5% respectively.…”

Characterization of recycled end-of-life rubber tire filled with black slag

“…Another important sector of use of ELTs is that of roads and infrastructures where, in addition to silent and long-lasting "modified" asphalts, there are cycle paths, street furniture, and elements for road safety. [6][7][8][9] These most common applications of ELT powder either use this material as a filler or a virgin polymer, such as EVA (Ethylene-vinyl acetate), is used as a binder.…”