Recycled Expanded Polystyrene Research Articles

Hybrid Matrix Using Polyester Resin to Improve the Physical and Mechanical Properties of Recycled Expanded Polystyrene Matrix

Hybrid Matrix Using Polyester Resin to Improve the Physical and Mechanical Properties of Recycled Expanded Polystyrene Matrix

Sustainable Hybrid Lightweight Aggregate Concrete Using Recycled Expanded Polystyrene.

Global concrete production, reaching 14×1013m3/year, raises environmental concerns due to the resource-intensive nature of ordinary Portland cement (OPC) manufacturing. Simultaneously, 32.7×109 kg/year of expanded polystyrene (EPS) waste poses ecological threats. This research explores the mechanical behavior of lightweight concrete (LWAC) using recycled EPS manufactured with a hybrid cement mixture (OPC and alkali-activated cement). These types of cement have been shown to improve the compressive strength of concrete, while recycled EPS significantly decreases concrete density. However, the impact of these two materials on the LWAC mechanical behavior is unclear. LWAC comprises 35% lightweight aggregates (LWA)-a combination of EPS and expanded clays (EC) - and 65% normal-weight aggregates. As a cementitious matrix, this LWAC employs 30% OPC and 70% alkaline-activated cement (AAC) based on fly ash (FA) and lime. Compressive strength tests after 28 curing days show a remarkable 48.8% improvement, surpassing the ACI 213R-03 standard requirement, which would allow this sustainable hybrid lightweight aggregate concrete to be used as structural lightweight concrete. Also obtained was a 21.5% reduction in density; this implies potential cost savings through downsizing structural elements and enhancing thermal and acoustic insulation. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy reveal the presence of C-S-H, C-(A)-S-H, and N-A-S-H gels. However, anhydrous products in the hybrid LWAC suggest a slower reaction rate. Further investigation into activator solution dosage and curing temperature is recommended for improved mechanical performance on the 28th day of curing. This research highlights the potential for sustainable construction incorporating waste and underscores the importance of refining activation parameters for optimal performance.

Feasibility of Using Lightweight Load-Bearing Panel Systems in Duplex Apartments of Tall Buildings

As an inevitable result of the growing population in recent times, the requirements of housing facilities, land scarcity, and overexploitation of natural resources have created many problems. One solution for the lack of land is to have multi-storey apartment buildings. Hence, over the last few decades, the number of tall buildings has seen an exponential increase. The apartment spread over two floors, is considered upmarket due to the larger floor area. However, one factor that has been a huge obstruction to promoting duplex apartments is the higher cost. In this study, a novel concept is introduced where a proper load-bearing floor is needed only once on two floors. The duplex is double-height, using lightweight concrete panels supporting lightweight concrete floors. Recycled expanded polystyrene (REPS) based light-weight panels are used as the load-bearing walls, and the NERD slab system is introduced for the intermediate floor. The structural performance was assessed using the comparison of two finite element models for duplex and conventional concepts. It was observed that the duplex concept is structurally feasible in comparison with the conventional concept. The study emphasises that an approximately 30% dead load reduction in typical floor levels has occurred due to the lightweight beam slab system in between floors.

Utilizing Recycled Expanded Polystyrene Plastics to Stabilize Metal–Organic Frameworks for Heterogeneous Catalysis

Polystyrene plastics present significant environmental and human health threats due to their poor recyclability and degradability. However, leveraging their properties to enhance material performance stands out as one of the most effective strategies for mitigating these issues. Here, we have employed recycled expanded polystyrene plastics to manufacture metal–organic framework/expanded polystyrene plastic composites (MOF@EPP) using an adverse solvent precipitation method. This method simultaneously recycles EPPs and safeguards moisture-sensitive MOFs. Due to the exceptional hydrophobic properties of EPPs, HKUST−1@EPP can maintain structural integrity even when immersed in water for 30 days. This method is applicable to other moisture-sensitive MOFs, such as MOF−74(Zn) and MIL−53(Al). The HKUST−1@EPP composite also exhibits desirable heterogeneous catalytic activity in the Knoevenagel condensation reaction between benzaldehyde and acrylonitrile. The conversion rate can reach 94.9% within 4 h at 90 °C and does not exhibit a significant decrease even after six cycles, even in the presence of water. This study not only introduces a novel concept for recycling polystyrene plastics, but also offers a practical strategy for safeguarding moisture-sensitive MOFs.

Performance Characterization and Evaluation of Innovative Cement Mortars and Concretes Made with Recycled EPS

The construction industry involves some of the activities with the highest consumption of raw materials and significant waste production. According to the European Commission, it requires large quantities of resources, representing approximately 50% of all extracted materials, and accounting for over 35% of the EU’s total waste production. In particular, the production and use of concrete, as well as that of EPS (expanded polystyrene), largely exploited for energy-efficient buildings, involve a substantial amount of extracted raw materials and waste. This study focuses on the development of construction materials, such as lightweight and thermally efficient mortars and concretes, incorporating recycled EPS (R-EPS) instead of fine aggregates. Mixtures were designed by partially or completely replacing the fine aggregate with R-EPS on a volume basis. All designed mortars exhibit compressive strength exceeding the minimum values required by Italian legislation and show thermal performance improvements of up to 89.49% compared to the reference mortar. Similarly, the concretes demonstrate strengths compliant with regulations and exhibit thermal characteristic enhancements, ranging from 27.68% for structural lightweight mixes to 74.58% for non-structural ones.

Effects of Recycled Expanded Polystyrene Beads on the Mechanical and Physical Properties of Cement-Stabilized Compressed Earth Bricks

Nowadays, research on environmentally friendly materials has become a significant challenge in the field of civil engineering. In this study, stabilized compressed earth bricks (CEBs) incorporating recycled expanded polystyrene (EPS) beads were studied with the aim of enhancing the development of green constructions. The mass contents of recycled EPS in CEB formulated at a compaction pressure of 5 MPa are 0%, 0.25%, 0.5%, 0.75%, and 1% relative to the mass of the soil, while cement type CEM I 32.5, as a stabilizer, constituted 8% by mass. Characterization was carried out by determining densities, dry and wet compressive strength, flexural strength, total water absorption, and capillarity. Sample properties were found to be strongly influenced by the percentage of recycled EPS. Increasing the EPS aggregate content led to a reduction in compressive strength in both wet and dry conditions. Samples with 0.5% EPS and 8% cement offered better physical and mechanical performance. Samples containing EPS had relatively low water absorption, which would contribute to good durability. These CEBs comply with the wall construction requirements for two-story dwellings. This study also demonstrates the potential use of this recycled material in the construction industry.

Influence of Recycled Expanded Polystyrene for Sustainable Structural Concrete

Influence of Recycled Expanded Polystyrene for Sustainable Structural Concrete

Thermal and Sound Insulation Properties of Recycled Expanded Polystyrene Granule and Gypsum Composites

Up to now, primary resources have been the main choice of raw material selection for production. Now, global market tendencies have brought significant attention to secondary resources as the price has been raised for primary materials, and there is a shortage of their delivery. This could bring an additional effort to increase the recycling level of construction and demolition waste, including expanded polystyrene (EPS). Efforts have been made to develop new efficient building materials with a high content of recycled EPS. In this paper, composite insulation material made of gypsum hemihydrate and recycled EPS beads by casting and compression methods were evaluated, and properties were compared. Thermal and sound insulation properties were characterized. Density from 48 to 793 kg/m3 was obtained and the thermal conductivity coefficient from 0.039 to 0.246 W/(m·K) was measured. Compression strength was from 18 kPa to 2.5 MPa. Composites produced with the compression method have a sound absorption coefficient α > 0.9 in the range from 600 to 700 Hz, while the samples produced by casting showed poor sound absorption with wide deviation. Compression methods had an advantage over the casting method as more homogenous and lightweight materials were produced with improved insulation properties.

Residual Strength and Thermal Conductivity of Self-Compacting Concrete with Recycled Expanded Polystyrene Subjected to High Temperatures

One of the most important processes of physical deterioration in concrete is the exposure to high temperatures that influences their durability and stability during life service. In addition, if self-compacting concrete is formed by lightweight aggregates, such as EPS, it is necessary to analyze its behaviour after it has been exposed to high temperature conditions. This research shows research that evaluates the effect EPS on the mechanical properties of self-compacting concrete at high temperatures. This study evaluated physical-mechanical properties, including residual compressive strength and thermal conductivity after exposure at 22oC, 150oC, 350oC, 500oC and ISO834. Experimental results showed that the loss of residual compressive strength of the specimens up to 350oC is almost insignificance, but it will be reduced by 49% and 70% when temperatures increase up to 500oC and 700oC respectively. EPS contributes to lightness, thermal insulation, and commitment to the environment in lightweight SCC.

Development of Recycled Expanded Polystyrene Nanofibers Modified by Chitosan for the Removal of Lead(II) from Water

Water contamination by potentially toxic metals and the generation of polymeric wastes are major world concerns. Therefore, novel recycled expanded polystyrene nanofibers modified by chitosan were successfully developed by centrifugal spinning and applied as adsorbents on the removal of lead(II) from water. Expanded polystyrene was obtained from waste food packaging. Characterization of the nanofibers presented diameters of 806 nm and functional groups suitable for the adsorption of lead(II). Under the experimental conditions used, lead(II) adsorption was favored at pH 6, at a temperature of 303 K, presenting an adsorption capacity of 28.86 mg g−1 and a removal percentage of 61.19%. The pseudo-second-order model was the most suitable to describe the kinetic data. The equilibrium data could be fitted by the Aranovich–Donohue model. The maximum adsorption capacity under the experimental conditions used was 137.35 mg g−1. The thermodynamics parameters presented the adsorption as spontaneous, favorable, and endothermic. After four cycles of desorption and reuse, the nanofibers maintained 63.04% of their original adsorption capacity. The findings indicated that these recycled modified nanofibers present great potential as lead(II)- (as well as other similar metals) adsorbent, with significant environmental relevance due to the recycling of a waste polymer into a notable toxic metal adsorbent.

Plastic/Natural Fiber Composite Based on Recycled Expanded Polystyrene Foam Waste.

A novel reinforced recycled expanded polystyrene (r-EPS) foam/natural fiber composite was successfully developed. EPS was recycled by means of the dissolution method using an accessible commercial mixed organic solvent, while natural fibers, i.e., coconut husk fiber (coir) and banana stem fiber (BSF) were used as reinforcement materials. The treatment of natural fibers with 5% (w/v) sodium hydroxide solution reduces the number of –OH groups and non-cellulose components in the fibers, more so with longer treatments. The natural fibers treated for 6 h showed rough surfaces that provided good adhesion and interlocking with the polymer matrix for mechanical reinforcement. The tensile strength and impact strength of r-EPS foam composites with treated fibers were higher than for non-filled r-EPS foam, whereas their flexural strengths were lower. Thus, this study has demonstrated an alternative way to produce recycled polymer/natural fiber composites via the dissolution method, with promising enhanced mechanical properties.

Sustainable atmospheric fog water generator through superhydrophobic electrospun nanocomposite fibers of recycled expanded polystyrene foams

In recent years, the production of disposable plastic products is increasing day by day and resulting in global growing concern that it poses to the environment. Microorganisms hardly resolve these types of plastic wastes; therefore, recycling the value-added materials is very important. Recycling and reusing plastic wastes to produce superhydrophobic nanofibers for atmospheric clean water production could be a partial solution to address the environmental issues. Herein, superhydrophobic-hydrophilic nanocomposites fibers were fabricated using recycled expanded polystyrene (REPS) as inspired by the fog-harvesting capability of Stenocara beetles in the Namib Desert. The REPS were electrospun with various proportions of titanium dioxide (TiO2) nanoparticles and aluminum (Al) microparticles. The fiber morphology, surface hydrophobicity, thermal properties, and fog water-harvesting performance of the nanocomposite fibers were studied. The as-prepared nanocomposites fibers with a 10% inclusion of combined micro-and nanoparticles exhibit superhydrophobic properties with a water contact angle of 157° and daily water productivity of more than 1.35 liter/m2 of nanocomposites. The expenses of materials to produce such nanocomposites needed to supply the minimum daily water consumption for a two-member household (6 liters) are only US$2.67. These nanocomposites are inexpensive, reusable, do not require additional energy consumption, and are particularly suitable for producing clean water in arid areas. This study offers a new technology for the mass production of clean water through nanotechnology at a relatively low cost.

Effect of Carbon Nanotube on properties of lightweight concrete using recycled Expanded Polystyrene (EPS)

Expanded Polystyrene based Lightweight concrete (EPS-C) is a lightweight material with low compressive strength and high energy absorption capacity. This type of concrete is mainly applied for heat and sound insulation, towards energy saving and sustainable development. In terms of composition, EPS-C is made from a mixture of cement, mineral additives, water, chemical additives, and Expanded Polystyrene Beads (EPS) which are small hollow spherical, impermeable, and non-toxic balls. In this paper, the EPS particles were replaced with recycled polystyrene particles as aggregates for lightweight concrete. Besides, carbon nanotube (nCNT) was added to improve the properties of the concrete. The experimental results show that (i) it is possible to use recycled EPS aggregate in making lightweight concrete with a density of less than 1200 kg/m3; (ii) the combination of nCNT improved significantly the properties of lightweight concrete, i.e. reducing the water absorption, increasing compressive strength; (iii) lightweight concrete with a very low thermal conductivity, corresponding to 0.152 W/m.°C for a sample with a density of 600 kg/m3.

Measuring the environmental performance of a circular system: Emergy and LCA approach on a recycle polystyrene system

The search for sustainability has pointed to the need to transition from a linear to a circular model. However, such a transition is not trivial. Modifying production chains with the focus on reducing virgin raw materials consumption, cut emissions, and prevent waste generation implies implementing new processes and services, which can add considerable environmental impacts to the supply chain. This paper analyzes a real case from a production system aligned with circular economy principles. The production system consists of the manufacturing of baseboards made of recycled Expanded Polystyrene (EPS), obtained from an extensive reverse logistics system composed of different recycling processes. The system's potential environmental impacts were assessed by two widely used methodologies, Life Cycle Assessment (LCA) and Emergy Analysis (EMA). For comparison purposes, the analysis was carried out for a fictional linear production system, in which the baseboard would be made of virgin EPS. EMA attributed a lower emergy load to the circular scenario compared to the linear scenario (8.62E+15 seJ to recycled EPS versus 1.26E+16 seJ to virgin EPS). LCA results indicate both scenarios as environmental preferable depending on the impact category under analysis (e.g. circular system has better performance regarding global warming, while the linear scenario demonstrated better results under water consumption). For the circular scenario, EMA identified the main impact drivers, such as transportation and electricity consumption. From LCA perspective impacts are also driven by electricity consumption. However, differently from EMA, logistics were only significant for Land Use impact category whereas Liquefied Petroleum Gas consumption and, landfill air emissions were identified as impact hotspots. These convergences and differences between the findings of LCA and EMA have demonstrated potentially complementation to broaden available information related to systems, enabling decision makers to act effectively in improving the environmental performance of their production processes, especially when implementing circular practices.

Recycled Expanded Polystyrene as Lightweight Aggregate for Environmentally Sustainable Cement Conglomerates.

In the present work the rheological, thermo-mechanical, microstructural, and wetting characteristics of cement mortars with recycled expanded polystyrene (EPS) were analyzed. The samples were prepared after partial/total replacement of the conventional sand aggregate with EPS having different grain size and size distribution. Lightness and thermal insulation were relevant features for all the bare EPS composites, despite the mechanical strengths. Specifically, EPS based mortars were characterized by higher thermal insulation with respect to the sand reference due to the lower specific mass of the specimens mainly associated with the low density of the aggregates and also to the spaces at the EPS/cement paste interfaces. Interesting results in terms of low thermal conductivity and high mechanical resistances were obtained in the case of sand-EPS mixtures although characterized by only 50% in volume of the organic aggregate. Moreover, sand-based mortars showed hydrophilicity (low WCA) and high water penetration, whereas the presence of EPS in the cement composites led to a reduction of the absorption of water especially on the bulk of the composites. Specifically, mortars with EPS in the 2–4 mm and 4–6 mm bead size range showed the best results in term of hydrophobicity (high WCA) and no water penetration in the inner surface, due to low surface energy of the organic aggregate together with a good particle distribution. This was indicative of cohesion between the ligand and the polystyrene as observed in the microstructural detections. Such a property is likely to be correlated to the observed good workability of this type of mortar and to its low tendency to segregation compared to the other EPS containing specimens. These lightweight thermo-insulating composites can be considered environmentally sustainable materials because they are prepared with no pre-treated secondary raw materials and can be used for indoor applications.

Development of a Composite Material Based on Wood Waste Stabilized with Recycled Expanded Polystyrene

Environmental pollution is a whole world concern. One of the causes of that pollution is the proliferation of plastic waste. Among these wastes there is expanded polystyrene (EPS), mainly from packaging. This study aims to valorize EPS waste by developing a composite material from EPS waste and wood waste. For this purpose, a resin made of EPS has been elaborated by dissolving EPS in acetone. That resin was used as a binder in volume proportions of 15%, 20%, 25% and 30% to stabilize the samples. Some of them were thermoformed. The method of elaboration was based on a device consisting of an extruder for mixing the constituents, and a manual press for shaping and compacting the samples. Analyses show that the drying time depends on the composition of the mixture. Increasing the resin content leads to reduce water absorption and porosity of the samples; it also contributes to homogenize the internal structure of the samples. However, for the same resin contents, the thermoformed samples are less porous; they have more homogeneous internal structure; and absorb less water than non-thermoformed samples.

Structural feasibility of Expanded Polystyrene (EPS) based lightweight concrete sandwich wall panels

In a global context where the need for quality housing is increasing with improved standard of living and growing population, the over exploitation of natural resources as building materials is becoming a serious problem. In this context, the conversion of non-bio degradable waste materials to quality building products would be extremely useful. In this research, the use of mechanically recycled Expanded Polystyrene as 50% of the total EPS used in a composite foam concrete panel has been assessed experimentally. The results of the experimental program have been interpreted with respect to various useful structural behaviors in compression and flexure. It is shown that the use of this foam concrete along with cement fiber boards produces a lightweight wall panel that can be used very effectively for load-bearing walls of single storey houses and non-loadbearing walls of multi-storey buildings. These lightweight panels can allow rapid construction while reducing the overall weight of the building.

Domestic Demand for and Recycling of Expanded Polystyrene, and Possibility of Recycling Expanded Polystyrene as Marine Litter

Domestic Demand for and Recycling of Expanded Polystyrene, and Possibility of Recycling Expanded Polystyrene as Marine Litter

Physicochemical Characterization of Nanocomposite Based on Recycled Expanded Polystyrene Reinforced with Clay: Application as Methanol Fuel Cell Membrane

Physicochemical Characterization of Nanocomposite Based on Recycled Expanded Polystyrene Reinforced with Clay: Application as Methanol Fuel Cell Membrane

Effect of Using Recycled Instead of Virgin EPS in Lightweight Mortars

Performances of structural, moderate and heat insulating lightweight mortars manufactured by replacing sand volume with virgin or recycled expanded polystyrene (EPS) are compared. At the same dosage, replacing virgin EPS with recycled one improves the mechanical performance of mortars without a significant variation in capillary water absorption and water vapour permeability. Recycled EPS mortars have lower thermal insulation properties than those manufactured with a virgin one, but this can be counteracted by increasing the percentage of EPS. To obtain mortars with a certain thermal insulating capacity, an economical saving over than 25% can be reached by using recycled EPS.