Bond to Bar Reinforcement of PET-Modified Concrete Containing Natural or Recycled Coarse Aggregates

Abstract

The use of post-consumer plastics in concrete production is an ideal alternative to dispose of such wastes while reducing the environmental impacts in terms of pollution and consumption of natural resources and energy. This paper investigates different approaches (i.e., reducing water-to-cement ratio and incorporating steel fibers or polymeric latexes) that compensate for the detrimental effect of waste plastics on the drop in concrete mechanical properties including the bond to embedded steel bars. The polyethylene terephthalate (PET) wastes used in this study were derived from plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete properties are degraded with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The threshold PET volumetric rates are 4.5% and 3% for concrete made using natural or recycled aggregates, respectively. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the concrete performance. The incorporation of 0.8% steel fibers (by volume) or 15% polymers (by mixing water) were appropriate to enhance the bridging phenomena and reduce the propagation of cracks during the pullout loading of steel bars.

Assessment of the Applicability of Selected Data Mining Techniques for the Classification of Mortars Containing Recycled Aggregate

“…In this group of wastes, polyolefins have the highest share, including polyethylene (PE) and polyethylene terephthalate (PET). The positive effects of modifying the composition of concrete and mortars with waste of these plastics were noted, among others, by the authors of works [1,6,[11][12][13][14].…”

“…The widespread consumption of natural aggregates and the progressive degradation of the environment force the search for alternative aggregates. It seems that the reuse of waste as aggregate for concrete may bring positive effects both in terms of the possibility of recycling waste and in terms of the protection of natural resources [6][7][8]. It is particularly important to manage plastic waste in this way, as it is known that the world's dependence on plastic is still growing [8][9][10].…”

Electrochemical C−H/C−C Bond Oxygenation: A Potential Technology for Plastic Depolymerization

“…[178][179][180] Particularly, fossil-based plastics like polystyrene, polyethylene, polyethylene terephthalate, and polypropylene are utilized on a regular basis, which causes an increase in the amount of waste being disposed of in landfills. [181][182][183][184][185][186][187] As a result, developing a strategy to address these issues that is both efficient and affordable has been difficult. Therefore, compared to landfilling and incineration, recycling technology not only minimizes toxic elements and waste pollution on the environment, [188][189][190] but it can also produce novel products with good mechanical and physical features.…”

“…It is generally recognized that plastic waste has a wide range of negative environmental effects, such as elevated energy consumption and exhaustion of greenhouse gases [178–180] . Particularly, fossil‐based plastics like polystyrene, polyethylene, polyethylene terephthalate, and polypropylene are utilized on a regular basis, which causes an increase in the amount of waste being disposed of in landfills [181–187] . As a result, developing a strategy to address these issues that is both efficient and affordable has been difficult.…”

Evaluation of Shear Capacity of Steel Fiber Reinforced Concrete Beams without Stirrups Using Artificial Intelligence Models

“…Concrete is currently the most widely used construction material [ 1 , 2 ]. However, it has some fundamental weaknesses: low tensile capacity and increased brittleness with strength.…”