Plastic Lumber Research Articles

EXPERIMENTAL STUDY ON THE STRUCTURAL BEHAVIOUR OF RECYCLED PLASTIC ONE STORY HOUSES

Recycling plastic materials may constitute a relief measure to the global plastic problem. Several companies are now producing recycled plastic for use as construction material in single-story houses. One commercially available layout involves assembling Recycled Plastic Lumber units in a running bond pattern, forming panels confined by horizontal and vertical tie elements joined through bolted steel plate connections. As production of houses is industrialized, the architectural layouts are standardized according to specific distribution and dimensions. This paper presents the findings of an experimental program aimed to characterize the seismic behavior and properties of a one-story house model. To facilitate practical application, the model is referred here as Architectural Standard Model (ASM). The objectives of the test campaign were to investigate the structural behavior of the constituting members and assemblies, and the response of structural walls to cyclic static lateral loads. Three natural scale wall specimens were tested in-plane and two out of plane. Results of natural scale cyclic loading tests demonstrated that structural system of the ASM can perform acceptably safely under high seismic loads if it is adequately fixed to the foundation. The results showed that out of plane loading was the critical pattern and behaved like a unidirectional plate that transmitted load to the columns. In plane observed behavior exhibited predominating rocking component, which suggests considering an evaluation of the system's response using dynamic methods.

Tackling Low-Value Plastics: Environmental and Health Concerns

Plastic pollution, spanning macroplastics to nanoplastics, poses multifaceted challenges. Low-value plastics (LVP), like multi-layered plastics (MLP) and soft plastics, are often discarded, exacerbating environmental issues. LVP's classification, with high collection costs and complex recycling, demands immediate attention. This study explores LVP management solutions, including converting to plastic lumber and RDF products. Anticipated advancements in multilayer plastic recycling offer hope, with downcycling as an option. LVP's environmental and health impacts, including microplastic contamination and toxin release during incineration, underscore the need for sustainable waste practices and plastic alternatives. Addressing LVP is crucial for environmental and human health, ensuring sustainability. Keywords: Low-value plastics, Multi-Layered Plastic (MLP), Health implications, Recycling challenges

Assessing benefits and risks of incorporating plastic waste in construction materials

Plastic pollution and climate change are serious and interconnected threats to public and planetary health, as well as major drivers of global social injustice. Prolific use of plastics in the construction industry is likely a key contributor, resulting in burgeoning efforts to promote the recycling or downcycling of used plastics. Businesses, materials scientists, institutions, and other interested stakeholders are currently exploring the incorporation of plastic waste into building materials and infrastructure at an accelerated rate. Examples include composite asphalt-plastic roads, plastic adhesives, plastic-concrete, plastic/crumb rubber turf, plastic lumber, plastic acoustic/thermal insulation, plastic-fiber rammed earth, and plastic soil reinforcement/stabilizers. While some believe this to be a reasonable end-of-life scenario for plastic waste, research shows such efforts may cause further problems. These uses of plastic waste represent an ongoing effort at “greenwashing,” which both delays and distracts from finding real solutions to the plastic pollution crisis. Hypothesized effects of incorporating plastic waste in construction materials, including economic, environmental, human health, performance, and social impacts, are evaluated in this mini review. We compare known impacts of these treatments for plastic waste and provide recommendations for future research. Evidence shows that such practices exacerbate the negative ecological, health, and social impacts of plastic waste and increase demand for continued production of new (virgin) plastics by creating new markets for plastic wastes. We urge caution—and more research—before widely adopting these practices.

Hysteresis modeling of structural systems using physics-guided universal ordinary differential equations

In this research, we develop three hysteretic structural models using two machine learning algorithms, namely physics-guided neural networks and universal ordinary differential equations. These models employ multilayer perceptrons and laws of nature to identify the hysteretic behavior of structures in an unbiased and physically consistent manner. These models might be regarded as an extension of the Bouc model of hysteresis, that enforces the Drucker and Il’iushin postulates in addition to other physical principles. We validate the proposed framework with experimental data of ferrocement and recycled plastic lumber walls, obtaining good accuracy, generalization and physical consistency. All data and codes used in this work are publicly available on GitHub.

Recycled Plastic Lumber walls for one and two-story housing: An assessment of their seismic performance

Recycled Plastic Lumber (RPL) is a sustainable material that has been proposed in the last years to develop structural systems for low-rise housing in high-seismic hazard zones to reduce plastic pollution and housing deficit. Recently, experimental and analytical studies have been conducted to determine the behavior and the damage states of RPL walls under cyclic loads, and promising results have been obtained. Based on that results, a Mostaghel’s six-lines hysteretic model was implemented to simulate the nonlinear behavior and energy dissipation capacity of the RPL walls. Subsequently, the seismic performance assessment of the RPL walls was obtained by nonlinear dynamic analyses using the FEMA P-695 far-field ground motions, which allowed develop fragility functions to estimate the probability of exceeding certain damage states as a function of an intensity measure of seismic hazard. The results of this study evidence that the RPL walls have a suitable seismic performance for their implementation in low-rise housing and meet precisely the Basic Safety performance objective established in the design philosophy of the NSR-10 Colombian building code for this kind of buildings.

A STUDY OF AVAILABLE TECHNOLOGY FOR RECYCLING LOW VALUE PLASTIC IN INDONESIA

Plastic has been an essential part of our daily life. However, the increasing plastic consumption has led to an increasing land and water contamination by said plastics. The Indonesian government has set five actions on managing marine plastic debris, one of them is by improving the plastic recycling system. Multilayer plastic was identified as a challenge to the plastic waste recycling. This is because there are differences in properties, such as melting point, which will cause difficulty in mechanical recycling. This study aims to create a mapping of available options to solve problems of low value plastic (LVP) waste in Indonesia and to assess the readiness level of key aspects in implementing the available options. Interviews was done with twelve experts on the field of material or energy recovery from plastic waste, especially LVP, to find the available technology options which include but not limited to their primary features, readiness status and feasibility, and potential market size. The evaluation was based on a set of criteria in technology, environment, social, and economy viewpoints. Three top low hanging options are conversion to plastic lumber, refuse derived fuel (RDF) production, and conversion to plastic products. All the three processes have mature technology and local availability. The challenges include a good branding and marketing strategy to expand market, endorsement, and recognition from government, including recycle content standard and more cost-effective collection. Further investigation has to be done for RDF utilization in industrial boilers. More promotion and introduction of recycled products have to be performed in order to create market to allow a sustainable recycling industry.

Valorization of Plastic Waste through Incorporation into Construction Materials

The growing plastic pollution has prompted the quest to reduce plastic waste sustainably and control the mismanaged plastic stream. The valorization of plastic waste through reusing and recycling has received much attention as a sustainable solution to the global plastic problem, and the construction sector provides an important avenue for such an endeavor. This review aims to present the latest advances in the valorization of plastic waste as construction and building materials through the review of 60 relevant scholarly papers and a content analysis of the papers. In the construction sector, plastic waste can be valorized as additives or raw materials for brick production. As additives, plastic waste is added at different proportions (1%–70%) with other materials, including non-plastic waste, followed by curing to acquire the desired properties. Plastic waste is used as a raw material to contain strength-imparting materials. The former has been reported to have good strengths (5.15-55.91 MPa), chemical, and thermal resistance, whereas the latter may impart lower strengths (0.67-15.25 MPa). Plastic waste is also used as additives for road pavement, primarily as substitutes for concrete-making materials, and was observed to produce desirable strengths (0.95–35 MPa) at appropriate proportions (0.5–25%), indicating the importance of optimizing the plastic contents in the concrete. Plastic waste has been recycled as plastic lumber, plastic-based door panels and gates, as well as insulation materials. Plastic-based construction materials are generally lightweight, resistant to chemicals and heat, and have good sound insulation, but they may pose a fire safety concern.

Use of Movable Bus Stop Loading Pads: Feasibility and Design Alternatives

The Americans with Disabilities Act (ADA) of 1990 requires bus stops to be accessible for individuals with disabilities. At a minimum, bus stops must have firm, stable, slip-resistant loading pads with connected sidewalks and curb ramps. Consequently, the typical approach of transit agencies has been to install permanent concrete loading pads at bus stops. This study explored alternatives to conventional concrete pads with movable pads that could be installed quickly, resulting in savings in construction and labor costs and minimizing both disruptions to traffic and impacts to abutting businesses. Potential design alternatives in terms of materials and structural support for these pads were evaluated. The review focused on existing and alternative design materials, especially in applications other than for transit purposes. Six materials were evaluated based on their structural performance, long-term durability, adaptability, life cycle cost, aesthetics, and safety and accessibility of transit riders with mobility devices. Of the six materials, plastic lumber and metal were found to have the highest potential to replace conventional designs. Two design alternatives that rely on the concept of bridge construction were introduced, both of which consist of four major components: foundation, slab, beam, and connections. These new design alternatives are anticipated to minimize maintenance of traffic and the need for heavy machinery to excavate, fill, and/or compact the soil.

Assessment of plastic lumber production in Brazil as a substitute for natural wood

Assessment of plastic lumber production in Brazil as a substitute for natural wood

Comparison of Energy Efficiency of traditional Brick Wall and Inco- Panel Wall: A Case Study of Hotel Sarowar in Pokhara

Energy efficiency is understood to mean the utilization of energy in the most cost-effective manner to carry out process or provide a service, whereby energy waste is minimized, and the overall consumption of primary energy resources is reduced. Various measures can be employed to attain energy efficiency in building such as reducing demands for heating, cooling, lighting, consumption for office equipment and appliances demand, reducing energy requirement for ventilation, using energy efficient building materials.
 An energy efficient home is designed to keep out the wind and rain while reducing energy waste. Modern homes are built with variety of different materials. They are no longer built using only bricks and mortar. A wide variety of energy efficient building materials are now available. Recycled Steel, Insulating Concrete Forms, Plant-based Polyurethane Foam, Straw Bales, Structural Insulated Panels, Plastic Composite Lumber, Vacuum Insulation Panels, Inco-panel are among alternatives available.
 Among those various wall materials, energy performance analysis in terms of heating and cooling load is done in this thesis. For this study, under construction Hotel Sarowar is chosen for analysis. This study compares heat transfer on the building when Inco-panel is used as wall material and conventional brick masonry is used as wall material. The heat transfers through those walls are calculated using MS Excel and ANSYS Software.

Modeling the Long-Term Deformation of a Geodesic Spherical Frame Structure Made from Wood Plastic Composite Lumber

The long-term deformation of a geodesic spherical frame structure with a diameter of 20 m made from wood plastic composite (WPC) lumber (struts) is described using the Norton-Bailey power law model to predict the service life creep behavior (the creep strain ( ε c r )) of the WPC. The Norton-Bailey power law model parameters, A the power law multiplier, n the stress order, and m the time order, were obtained from experimental four-point bending flexural creep measurements of WPC lumber subjected to three levels of flexural stress: 7, 14, and 29% of the ultimate flexural strength for 200 days. The parameters obtained from the experiments showed good agreement to the model of the WPC lumber in flexure. The Norton-Bailey power law parameters were then implemented to describe the long-term deformation of the spherical frame structure. The limit of failure was considered when the WPC creep strain reaches the value of 1%. However, the FEA predicted the maximum creep strain to be 20% of the failure strain. This modeling approach is considered useful to describe and predict the long-term deformation of aquacultural structures made from viscoelastic materials during the envisioned service life (10 years) based on experimental creep data for the members that form the structure.

Flexural Creep Behavior of High-Density Polyethylene Lumber and Wood Plastic Composite Lumber Made from Thermally Modified Wood.

The use of wood plastic composite lumber as a structural member material in marine applications is challenging due to the tendency of wood plastic composites (WPCs) to creep and absorb water. A novel patent-pending WPC formulation that combines a thermally modified wood flour (as a cellulosic material) and a high strength styrenic copolymer (high impact polystyrene and styrene maleic anhydride) have been developed with advantageous viscoelastic properties (low initial creep compliance and creep rate) compared with the conventional WPCs. In this study, the creep behavior of the WPC and high-density polyethylene (HDPE) lumber in flexure was characterized and compared. Three sample groupings of WPC and HDPE lumber were subjected to three levels of creep stress; 7.5, 15, and 30% of the ultimate flexural strength (Fb) for a duration of 180 days. Because of the relatively low initial creep compliance of the WPC specimens (five times less) compared with the initial creep compliance of HDPE specimens, the creep deformation of HDPE specimens was six times higher than the creep deformation of WPC specimens at the 30% creep stress level. A Power Law model predicted that the strain (3%) to failure in the HDPE lumber would occur in 1.5 years at 30% Fb flexural stress while the predicted strain (1%) failure for the WPC lumber would occur in 150 years. The findings of this study suggest using the WPC lumber in structural application to replace the HDPE lumber in flexure attributable to the low time-dependent deformation when the applied stress value is withing the linear region of the stress-strain relationship.

Ammonium zeolite and ammonium phosphate applied as fire retardants for microcrystalline cellulose filled thermoplastic composites

In this study, mechanical, thermal, fire and morphological properties of thermoplastic composites filled with fire retardants (FRs) and microcrystalline cellulose (MCC) were investigated in detail. The composites were produced through the extrusion + injection molding methods using MCC, FRs and high density polyethylene (HDPE). Based on the composites dry-weights, 10%wt. of mono ammonium phosphate (MAP), ammonium zeolite (AZ) or natural zeolite (NZ) were incorporated into polymer matrix for improving reaction of fire of the composites, and their effects on technological properties were evaluated. MAP had a positive effect on tensile and flexural moduli of the composites whilst tensile strength, elongation at break and impact strength properties of the composites were decreased. The highest tensile and flexural strength values were obtained from HDPE/MCC/AZ samples, respectively, 22.13 MPa and 29.93 MPa. The minimum value for impact strength was obtained from HDPE/MCC/MAP5/AZ5 composite (1.68 kJ/m2) whereas the maximum value for impact strengths were achieved from control HDPE composite (5.15 kJ/m2) and HDPE/MAP10 (3.30 kJ/m2). Flexural strength and flexural modulus values of all HDPE composites were higher than the requirement by the ASTM D 6662 standard for polyolefin based plastic lumber decking boards. As the MCC content increased, the initial, maximum and final degradation temperatures of HDPE composites have not been influenced greatly. Thermogravimetric and differential scanning calorimetry analyses showed that the maximum rate weight loss temperature and the crystalline features of HDPE have not been significantly influenced by addition of MCC. Limiting Oxygen Index (LOI) level and charring increased when FRs were incorporated into polymer matrix. In addition, the burning rates of HDPE/MAP10 and HDPE/MCC/MAP5/AZ5 composite were slowed down by 64% and 62%, respectively. It was found that no burning in HDPE/MCC/MAP10 was observed composite during the horizontal burning test. Especially; HDPE/MCC/MAP samples can be used for building products because they meet the CC1 (plastic materials that have a burning extent of 25 mm or less where tested at a nominal thickness of 1.5 mm, or in the thickness intended for use, in accordance with ASTM D 635) class requirements of international building code which means a model building code improved by the International Code Council. In the light of obtained results, it was specified that use of FRs improved morphological, thermal and reaction of fire of the MCC filled HDPE composites.

Seismic behavior of recycled plastic lumber walls: An experimental and analytical research

Recycled Plastic Lumber (RPL) is a wood-like material made from recycled plastics that aims to diminish the environmental pollution resulting from plastic wastes. This material is used in different kinds of nonstructural and structural applications. Recently, RPL has been proposed as a suitable material to develop structural walls that comprise the seismic resistant system of housings, in order to lessen the housing deficiency. This article presents the results drawn from an experimental campaign carried out over three full-scale RPL walls, which were tested under cycling loading conditions to determine structural parameters such as strength, hysteretic behavior, ductility, energy dissipation, equivalent damping and characteristic failure modes of the RPL walls, which are necessary to design and to assess seismically the housings. Finally, a multilinear hysteretic model capable of simulating the nonlinear dynamic behavior exhibited by RPL walls was implemented, in order to simulate and to assess the seismic behavior of them under strong and destructive real earthquakes.

Mechanical properties: wood lumber versus plastic lumber and thermoplastic composites

Abstract Plastic lumber and thermoplastic composites are sold as alternatives to wood products. However, many technical standards and scientific studies state that the two materials cannot be considered to have the same structural behaviour and strength. Moreover, there are many compositions of thermoplastic-based products and plenty of wood species. How different are their mechanical properties? This study compares the modulus of elasticity and the flexural, compressive, tensile and shear strengths of such materials, as well as the materials' specific mechanical properties. It analyses the properties of wood from the coniferae and dicotyledon species and those of commercialized and experimental thermoplastic-based product formulations. The data were collected from books, scientific papers and manufacturers' websites and technical data sheets, and subsequently compiled and presented in Ashby plots and bar graphs. The high values of the compressive strength and specific compressive and tensile strengths perpendicular to the grain (width direction) shown by the experimental thermoplastic composites compared to wood reveal their great potential for use in compressed elements and in functions where components are compressed or tensioned perpendicularly to the grain. However, the low specific flexural modulus and high density of thermoplastic materials limit their usage in certain civil engineering and building applications.

Engineering Relief for Haiti

In January of 2010, Haiti suffered a 7.0-magnitude earthquake that killed 220,000 people, injured 300,000, and left over 1.5 million homeless. Recognized as the poorest country in the western hemisphere, the country has limited resources to rebuild the cities and villages damaged by the natural disaster. Since the earthquake, thousands of Haitians have continued to live in unsafe housing. A team of eight undergraduate students from the Rose-Hulman Institute of Technology (RHIT) Summer 2014 Grand Challenge Program team developed a project that addressed this housing crisis: plastic lumber. The Grand Challenge course is a teamtaught multidisciplinary design, build, and document class, with professors from the Mechanical Engineering, Physics and Optics, and Humanities and Social Sciences departments. While the three professors presented the students with the task of developing and designing a project for Haiti disaster relief, the concepts, solutions, ideas, and designs originated with the student team in just nine weeks.

A Perspective on the Prowaste Concept: Efficient Utilization of Plastic Waste through Product Design and Process Innovation.

This work is aimed to present an innovative technology for the reinforcement of beams for urban furniture, produced by in-mold extrusion of plastics from solid urban waste. This material, which is usually referred to as “recycled plastic lumber”, is characterized by very poor mechanical properties, which results in high deflections under flexural loads, particularly under creep conditions. The Prowaste project, founded by the EACI (European Agency for Competitiveness and Innovation) in the framework of the Eco-Innovation measure, was finalized to develop an innovative technology for selective reinforcement of recycled plastic lumber. Selective reinforcement was carried out by the addition of pultruded glass rods in specific positions with respect to the cross section of the beam, which allowed optimizing the reinforcing efficiency. The reinforcement of the plastic lumber beams with pultruded rods was tested at industrial scale plant, at Solteco SL (Alfaro, Spain). The beams obtained, characterized by low cost and weight, were commercialized by the Spanish company. The present paper presents the most relevant results of the Prowaste project. Initially, an evaluation of the different materials candidates for the reinforcement of recycled plastic lumber is presented. Plastic lumber beams produced in the industrial plant were characterized in terms of flexural properties. The results obtained are interpreted by means of beam theory, which allows for extrapolation of the characteristic features of beams produced by different reinforcing elements. Finally, a theoretical comparison with other approaches which can be used for the reinforcement of plastic lumber is presented, highlighting that, among others, the Prowaste concept maximizes the stiffening efficiency, allowing to significantly reduce the weight of the components.

Effect of bark flour on the mechanical properties of HDPE composites

The objective of this study was to evaluate the replacement of wood flour by Turkish pine bark residues for production of wood plastic composites. High density polyethylene was chosen as matrix and seven different compositions were used for production of composites. In order to compare the effect of bark residues flour as a filler, bark residues-HDPE composites were produced with various wt% bark residues loading (10, 20, 30 and 40 wt%). Bark residues filled HDPE pellets were produced by using a twin-screw extruder, then 25 cm (l) x 25 cm (w) and 2 mm (t) composites were produced with compression molding technique according to ASTM D4703-10. For each composition, three composites were produced. Tensile and flexural tests were performed with a Universal Testing machine. Impact strength was measured with a Zwick HIT5.5P Impact Testing machine. Tensile and impact strength of the composites decreased with increasing bark flour loading whereas bending strength and modulus of eleasticity values were improved with addition of the bark flour. All produced bark flour filled composites showed better modulus of elasticity and bending strength properties than ASTM D6662-13 standard requirements for polyolefin-based plastic lumber. Morphological properties of bark residues-HDPE composites were characterized by scanning electron microscopy (SEM) technique.

Mechanical Property of Plastic Lumber Produced from Recycled High Density Polyethylene (HDPE)

Recycling is a strategy to combat environmental pollution due to plastic wastes. Of the many plastic wastes, researchers confirmed the possibility to produce plastic lumber from used HDPE plastics. The aim of this study is to experimentally determine the mechanical property of the plastic lumber produced from pure HDPE and its composite with wood to proof usability and applicability for different purpose. The experiment considered different conditions. Pure plastic lumber and wood plastic composite lumber is initially produced and examined under room temperature and below room temperature. Under each condition, bending, tensile and impact strength were examined. For each test eight specimens were prepared based on international standards and the experiments were conducted using standard testing machines. The result shows that pure plastic lumber has demonstrated superior load carrying capability, tensile load resistance capability and impact load resistance at room temperature. Moreover, the pure plastic lumber has an elastic nature and the wood composite has a brittle nature. In both cases the mechanical property of the plastic lumber permits to use for different applications. This has been also tested and resulted in similar phenomena at 20C below room temperature.

MDF atıklarının odun plastik kompozitlerin üretiminde değerlendirilmesi

The aim of this study was to evaluate the potential utilization of fibre board waste generated from forest industry and furniture manufacturers in the production of wood plastic composite (WPC) for replacing wood flour. For production of WPC, polypropylene (PP) was chosen as polymer matrix, and eight different compositions were prepared with the co-rotating twin-screw extruder to compound them into pellets. WPC were produced at the size of 25 cm x 25 cm and 2 mm from these pellets (MDF flour loading varies 10 to 50 weight %) by hot press with the compression moulded technique according to ASTM D4703-10. For each composition, three composites were produced and ten specimens were prepared from these composites for tensile, flexural and notched impact specimens The tensile, flexural and impact properties of the manufactured samples were determined in accordance with ASTM D638, ASTM D6109, and ASTM D256, respectively. Morphological properties of the samples were characterized with scanning electron microscopy (SEM) analysis. Tensile and impact strength values decreased with increasing MDF flour loading whereas MOE values were improved with addition of MDF flour. All produced MDF flour filled composites showed better MOE and bending strength properties than ASTM D6662-13 standard requirements for polyolefin-based plastic lumber. Keywords: Wood plastic composites, Polypropylene, Medium density fiberboard flour