The National Academies Press

Currently Skimming:

Pages 133-174

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 133... ... 133 7 Applications of Recycled Plastics in Other Infrastructure As part of a larger effort to reduce plastics waste in landfills and the environment, plastics waste has been and continues to be the subject of investigation as feedstock for plastic materials and products across a myriad of infrastructure applications. Due to the perceived widespread availability of recycled plastics, fluctuations in virgin plastic pricing, and consumer and manufacturer interest in products with improved environmental impacts, demand for infrastructure applications that include recycled plastics has increased. Read the entire page →
From page 134... ... 134 RECYCLED PLASTICS IN INFRASTRUCTURE applications depends not only on the performance of plastics, particularly recycled plastics, but also industry and state government motivation to develop new standards that accommodate their use. As one speaker shared with the committee, until these standards and specifications are established, the use of recycled plastics in certain industries will remain largely innovative. Read the entire page →
From page 135... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 135 Cross-linking can be used to modify the thermoplastic properties of a product, such as the melt flow index or creep resistance. Plastics that have been cross-linked, however, cannot be recycled again through melting. Read the entire page →
From page 136... ... 136 RECYCLED PLASTICS IN INFRASTRUCTURE • ASTM D7031, Standard Guide for Evaluating Mechanical and Physical Properties of Wood-Plastic Composite Products (ASTM 2019a) ; and • ISO 20819-1, Wood-Plastic Recycled Composites (WPRC) Read the entire page →
From page 137... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 137 plastic lumber is free of the chemicals used to treat wood lumber. However, plastic materials are vulnerable to weathering and degradation because of UV radiation (Breslin et al. Read the entire page →
From page 138... ... 138 RECYCLED PLASTICS IN INFRASTRUCTURE • ASTM D6109, Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products (ASTM 2019c) ; • ASTM D6111, Standard Test Method for Bulk Density and Specific Gravity of Plastic Lumber and Shapes by Displacement (ASTM 2019d) Read the entire page →
From page 139... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 139 Plastic pilings are typically made from HDPE (Guades et al. 2010; Iskander 2012) Read the entire page →
From page 140... ... 140 RECYCLED PLASTICS IN INFRASTRUCTURE of plastic pilings is two to three times the amount of pilings made of wood (Heinz 1993) , Marc Hollahan of Tangent shared that the costs are recouped in approximately 8 to 12 years because of the reduced maintenance requirements of plastic pilings.2 Composite plastic piles, as with all plastic lumber, are appropriately used only in environments with small, infrequent loading (Levie 1993) Read the entire page →
From page 141... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 141 Traditionally, railroad ties have been manufactured from wood. Wood has shock absorption properties that reduce wear and tear of the rails and rolling stock. Read the entire page →
From page 142... ... 142 RECYCLED PLASTICS IN INFRASTRUCTURE Although composite railroad ties made from recycled plastics have been deployed successfully in select projects, they have an uneven performance and deployment history (McHenry et al. Read the entire page →
From page 143... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 143 of the tie at the location of the spike hole. Predrilling adds an extra step in the field in comparison to wooden ties. Read the entire page →
From page 144... ... 144 RECYCLED PLASTICS IN INFRASTRUCTURE Life-Cycle Analyses Plastic ties could lead to increased environmental benefits from these products. For example, according to composite rail tie manufacturers, 1.8 million metric tons of recycled plastics could be incorporated into the near 20 million railroad ties needed annually.5 However, there are no published life-cycle analyses to verify the claim. Read the entire page →
From page 145... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 145 of wooden poles is determined in part by regional climate and other factors that affect the rates of decay. While timber poles are the dominant type of utility pole, poles may also be made from galvanized steel, concrete, and fiber-reinforced polymer (FRP) Read the entire page →
From page 146... ... 146 RECYCLED PLASTICS IN INFRASTRUCTURE Composite poles experience higher deflections due to wind and other lateral loads than steel or concrete (Barone et al. Read the entire page →
From page 147... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 147 weight. PVC pipes are manufactured in a wide range of sizes. Read the entire page →
From page 148... ... 148 RECYCLED PLASTICS IN INFRASTRUCTURE HDPE, draft revisions to AASHTO Bridge Design Specifications to include material properties for pipes manufactures with recycled content, and an ASTM test method F3181 for evaluating crack stress of these materials (ASTM 2016) Read the entire page →
From page 149... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 149 BOX 7-2 Continued The pipes produced meet the ASTM and AASHTO specifications for land drainage applications (ASTM F2648) ,a for storm sewer applications (ASTM F2306 and AASHTO M 294) Read the entire page →
From page 150... ... 150 RECYCLED PLASTICS IN INFRASTRUCTURE Natural Gas Pipelines HDPE and PVC plastic pipes have been used in the natural gas industry since the late 1950s. While most natural gas gathering (i.e., upstream distribution) Read the entire page →
From page 151... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 151 space under the bike path deck, allowing water to drain away from the bike path surface even in extreme rain and later gradually infiltrate into the local subsoil. Figure 7-2 presents a bike path sign in Zwolle illustrating the water drainage feature of the PlasticRoad. Read the entire page →
From page 152... ... 152 RECYCLED PLASTICS IN INFRASTRUCTURE bicycle path. A second pilot, in Giethoorn (the Netherlands) Read the entire page →
From page 153... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 153 FHWA's 1995 Highway Traffic Noise Analysis and Abatement Policy and Guidance allows the state DOTs flexibility in creating State Noise Abatement Policies, and this flexibility has carried over into noise barrier design (Office of Environment and Planning Noise and Air Quality Branch 1995) Read the entire page →
From page 154... ... 154 RECYCLED PLASTICS IN INFRASTRUCTURE plastic walls is minor. Fewer than 1 percent of single-material walls in the United States are manufactured with plastics (see "Single-material construction: other materials" in Figure 7-3) Read the entire page →
From page 155... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 155 BOX 7-3 HDPE Noise Wall Panel: A Case Study Along the Mordialloc Freeway in Victoria, Australia, 32,000 square meters of noise wall panels manufactured with recycled HDPE were successfully installed in 2021 as a pilot project for the state's Recycle First policy. Rotationally molded plastic panels were formed from 570 tons of hard and soft recycled HDPE plastics. Read the entire page →
From page 156... ... 156 RECYCLED PLASTICS IN INFRASTRUCTURE cycles, which can impact the strength and stiffness of the material (Saadeghvaziri and MacBain 1998) Read the entire page →
From page 157... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 157 Geosynthetics are highly engineered, durable products with a potential design life of more than 100 years.14 Additionally, they typically do not contain harmful chemicals, and their constituent polymers are not easily lost into the environment. Geosynthetics are thermoplastics and can be recycled at the end of their design life. Read the entire page →
From page 158... ... 158 RECYCLED PLASTICS IN INFRASTRUCTURE Recycled plastics might also be employed in the form of pins for slope stabilization (Bowders et al. 2003; Islam et al. Read the entire page →
From page 159... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 159 Concrete Additives and Aggregates Concrete is a mixture of water, cement, fine aggregate, and coarse aggregate, with aggregate as the predominant component. Water and cement react chemically to create a paste binder for the aggregate. Read the entire page →
From page 160... ... 160 RECYCLED PLASTICS IN INFRASTRUCTURE experimentation. The authors found that plastic reduced the weight of concrete samples and reduced strength metrics. Read the entire page →
From page 161... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 161 differently sized particles that were then compacted and heated. The PET particles were mixed with a disturbed soil sample of clayey sand to form compressed earth bricks. Read the entire page →
From page 162... ... 162 RECYCLED PLASTICS IN INFRASTRUCTURE FIGURE 7-5 Photo of a ByFusion block. SOURCE: Chris Piotrowski, ByFusion. Read the entire page →
From page 163... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 163 together the reinforcing fibers. The blades are cut and shredded to produce small pellets, which are then processed to produce construction and flooring panels (Jacoby 2022) Read the entire page →
From page 164... ... 164 RECYCLED PLASTICS IN INFRASTRUCTURE than 16 inches.20 The HDPE spheres are manufactured via blow molding, while injection molding is used for the polypropylene spheres. Post-industrial plastics, such as HDPE from ground-up, off-specification kayaks, are used as feedstock to ensure product quality and avoid the manufacturing problems that can ensue from the presence of contamination, especially for the blow molding process.21 ROLE OF PUBLIC AGENCIES AND OTHER INFRASTRUCTURE OWNERS The use and value of recycled plastics in infrastructure components need to be understood by the various stakeholders of the infrastructure ecosystem, including public agencies, private infrastructure owners, designers and contractors, procurement professionals, and the general public. Read the entire page →
From page 165... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 165 Life-Cycle Considerations, there are special considerations to make in the emerging uses of recycled plastics in infrastructure. Those considerations vary relative to programmatic or project-level lifecycle cost and cost-benefit analysis. Read the entire page →
From page 166... ... 166 RECYCLED PLASTICS IN INFRASTRUCTURE been inhibited by factors that include high material and installation costs, uncertainties about long-term performance and environmental impacts, and general lack of familiarity with the products. Other applications, such as plastic bricks, are a recent market development and, as such, there are no historical data regarding their engineering and environmental performance. Read the entire page →
From page 167... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 167 and specifications exist for the use of recycled plastics in some applications (e.g., drainage pipes and plastic lumber) , others will need to be developed or incorporated into existing specifications and standards for the remaining applications. Read the entire page →
From page 169... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 169 BubbleDeck. Read the entire page →
From page 170... ... 170 RECYCLED PLASTICS IN INFRASTRUCTURE Hag-Elsafi, O., Elwell, D J., Glath, G., and Hiris, M Read the entire page →
From page 171... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 171 Kou, S Read the entire page →
From page 172... ... 172 RECYCLED PLASTICS IN INFRASTRUCTURE Najafi, S K., Tajvidi, M., and Hamidina, E Read the entire page →
From page 173... ... APPLICATIONS OF RECYCLED PLASTICS IN OTHER INFRASTRUCTURE 173 Rigby, N Read the entire page →
From page 174... ... 174 RECYCLED PLASTICS IN INFRASTRUCTURE Waita, E Read the entire page →

From page 133...

... 133 7 Applications of Recycled Plastics in Other Infrastructure As part of a larger effort to reduce plastics waste in landfills and the environment, plastics waste has been and continues to be the subject of investigation as feedstock for plastic materials and products across a myriad of infrastructure applications. Due to the perceived widespread availability of recycled plastics, fluctuations in virgin plastic pricing, and consumer and manufacturer interest in products with improved environmental impacts, demand for infrastructure applications that include recycled plastics has increased.