Expanded Polystyrene Beads Research Articles

Bonding strength of steel and concrete containing Palm Oil Fuel Ash (POFA) and Expanded Polystyrene (EPS)

The usage of recycled materials in concrete has become popular recently. This paper focuses on a study related to the bonding between steel and concrete containing expanded polystyrene beads (EPS) and palm oil fuel ash (POFA) as replacement material. The EPS were used as fine aggregate replacement, and POFA was used as cement replacement. The replacement percentages for EPS and POFA in the concrete were limited to a range of 0-30% and 0-10%, respectively. Previous studies have identified the potential of POFA and EPS as concrete substances. The typical issue with EPS-containing concrete is its characteristic weakness, which leads to a compromised bond with steel. This occurs because EPS fails to effectively interact with cement, resulting in a weak bond and low compressive strength. Consequently, in this study, POFA is introduced as an addition to enhance the bond strength between EPS-containing concrete and steel. Pull-out tests in this study seem to represent the bonding performance between concrete and steel. The 10% of POFA in concrete seems might improve its performance in terms of compression strength, and bonding between concrete and steel.

Mechanical Properties of Lightweight EPS Self-compacting Concrete Reinforced with Steel Fibers

This study aims to evaluate experimentally the mechanical characteristics of Self-Compacting Concrete (SCC) comprising expanded polystyrene beads (EPS) to produce flowable lightweight concrete reinforced with steel fibers. In this paper, the effect of steel fibers and EPS content on the fresh and hardened mechanical properties of SCC specimens, using two percentages for Polystyrene aggregate replacement (25% and 50%) and three values for volume fraction of steel fiber content (0%, 0.75%, and 1.5%), were examined. Fresh mixture properties were determined using slump flow, L-box, and V-funnel tests. Mechanical properties for hardened samples were obtained using standard specimens for compressive strength, density, split, and flexural strength. The study showed that EPS content has no adverse effect on the rheological features of the SCC. However, workability falls below specification limits when adding steel fibers to SCC. Results revealed that using 25% of EPS content resulted in lightweight structural concrete, while lightweight moderate-strength concrete was produced using 50% of EPS content. Furthermore, the study has shown that the split and flexural tensile strength were reduced substantially by 53% and 60% due to EPS addition. However, adding steel fibers remarkably improved the indirect tensile strength and Modulus of rupture by 46% and 80%, respectively. The mode of failure of the concrete specimens containing EPS beads and steel fibers did not show brittle failure behavior generally encountered in normal-weight concrete, indicating a more ductile behavior.

Predictive models for treated clayey soils using waste powdered glass and expanded polystyrene beads using regression analysis and artificial neural network

Waste materials contribute to a wide range of environmental and economic problems. To minimize their effects, a safe strategy for reducing such negative impact is required. Recycling and reusing waste materials have proved to be effective measures in this respect. In this study, an eco-friendly treatment is investigated based on using waste powdered glass (WGP) and EPS beads (EPSb) as mechanical and chemical admixers in soils. For this purpose, Atterberg limit, standard proctor, free swell, and unconfined compression tests are performed on soil samples with different ratios of waste materials at their optimum moisture contents. The obtained test results indicate that adding WGP to cohesive soils increases the unconfined compressive strength (UCS) and reduces free swell (FS). In contrast, using EPSb reduces both FS and UCS of the treated soil samples. An optimum combination of both waste materials is determined for the improvement of the properties of high plasticity clay used in this study. Furthermore, multiple linear regression (MLR) and artificial neural network (ANN) methods are used to predict the FS and UCS of the clayey soils based on the data obtained here and the experimental test results reported in the literature. Once the FS and UCS values of untreated soil and additive percentages are defined as independent variables, both methods are shown to predict the FS and UCS values of the treated soil samples on a satisfactory level with the coefficient of correlation (R2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${R}^{2}$$\\end{document}) values greater than 0.926. Additionally, when only the index properties (liquid limit, plastic limit, and plasticity index) of the soil samples with waste materials are used as dependent variables, the R2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${R}^{2}$$\\end{document} values obtained by the ANN method are 0.968 and 0.974 for FS and UCS, respectively. The results of the untreated soil samples' FS and UCS tests are known, and the linear regression and ANN techniques yield similar results. Lastly, the ANN method is used to predict the FS and UCS of the treated samples in accordance to the limited predictors (e.g., only the Atterberg limits of the soil sample).

Effect of Expanded Polystyrene Beads on Mechanical, Thermal, and Acoustic Properties of Lightweight Concrete

Effect of Expanded Polystyrene Beads on Mechanical, Thermal, and Acoustic Properties of Lightweight Concrete

Enhancing Sustainability in Construction: Investigating the Thermal Advantages of Fly Ash-Coated Expanded Polystyrene Lightweight Concrete

This study investigates a sustainable coating method for modified expanded polystyrene (MEPS) beads to improve the thermal insulation of lightweight concrete intended for wall application. The method employed in this study is based on a novel coating technique that represents a significant advancement in modifying Expanded Polystyrene (EPS) beads for enhanced lightweight concrete. This study experimentally assessed the energy-saving capabilities of MEPS concrete in comparison to control groups of uncoated EPS beads and normal concrete by analysing early-stage temperature, thermal conductivity, specific heat capacity, heat flux, and thermal diffusivity. The thermal conductivity of MEPS concrete is approximately 40% lower than that of normal concrete, demonstrating its usefulness in enhancing insulation. The heat flux calculated for MEPS concrete is significantly reduced (approximately 35%), and it has a 20% lower specific heat capacity than ordinary concrete, indicating a reduction in energy transfer through the material and, thus, potential energy-efficiency benefits. Furthermore, the study discovered that all test objects have very low thermal diffusivity values (less than 0.5 × 10−6 m2/s), indicating a slower heat transport through the material. The sustainable coating method utilized fly ash-enhanced thermal efficiency and employed recycled materials, hence decreasing the environmental impact. MEPS concrete provides a practical option for creating sustainable and comfortable buildings through the promotion of energy-efficient wall construction. Concrete incorporating coated EPS can be a viable option for constructing walls where there is a need to balance structural integrity and adequate insulation.

The behaviour of Reinforced Concrete Beams by Using Expanded Polystyrene Beads and Palm Oil Fuel Ash as Replacement Materials

The Reinforced Concrete (RC) beams containing Expanded Polystyrene Beads (EPS) and Palm Oil Fuel Ash (POFA) as sand and cement replacement with a percentage between 10% and 30% were studied in terms of load-deflection behaviour. RC beam’s size was 1000×150×150 mm and simply supported at spaced 750 mm apart. The 10% of POFA without EPS shows a slight increase which is 0.26% higher than normal concrete in compressive strength. The ultimate load and flexural performance of RC beams with EPS and POFA exhibited a decreasing trend. All beams’ ultimate load exceeds the design value. The cracks of the RC beam may be classified as vertical flexural cracks, and some of the cracks can be classified as shear cracks based on the crack angle. As the percentage of EPS and POFA increases above 20% for all specimens, cracking starts to change to shear cracking.

A review on innovative approaches to expansive soil stabilization: Focussing on EPS beads, sand, and jute

Abstract Expansive soils pose major geotechnical challenges due to significant volume changes. This research investigates an innovative stabilization approach using sand, expanded polystyrene (EPS) beads, and jute fibres to enhance the properties of expansive soil. The purpose is to utilize the unique characteristics of these admixtures to restrict swelling potential and improve strength and load-bearing capacity. Experimental testing quantified improvements through parameters like unconfined compressive strength (UCS), swelling pressure, California bearing ratio (CBR), compaction characteristics, and Atterberg limits. Soil samples were prepared with individual and combined admixtures at optimum proportions and extensively tested after proper curing. Quantitative results indicated that including sand, EPS beads, and jute fibres increased the soil’s UCS by 41, 29, and 23%, respectively. The swelling pressure, on the other hand, decreased by 14, 18, and 11%, respectively. Maximum improvements were achieved with combined admixtures: UCS increased by 65%, swelling pressure reduced by 23%, and CBR improved from 5 to 6.5%. Regression analysis indicated a strong correlation (R 2 = 0.96) between admixture proportions and resultant UCS. The key achievements are effective swelling control, a marked increase in shear strength parameters, and synergy between admixtures in enhancing expansive soil properties. This sustainable stabilization method using industrial by-products presents a promising solution for constructing stable civil structures even in problematic expansive soil regions.

Investigation into the mechanical and thermal properties of lightweight mortar using commercial beads or recycled expanded polystyrene

Abstract The addition of recycled expanded polystyrene (EPS) in cement mortar is a key to enhancing buildings’ insulation and reducing energy consumption. The main objective of this study is to improve the thermal conductivity of lightweight mortar (LWM) by using the EPS. Also, to overcome the segregation problem when increasing the EPS proportion by more than 70% by volume, slurry sand was used. To achieve that, more EPS waste is required to produce an LWM with less cement and natural resources (sand) content. The effect of different percentages and particle sizes of the EPS either virgin or grated on the workability, density, compressive, flexural strength, and thermal conductivity were investigated by using the EPS with the range of 0, 75, 80, and 85% by mortar’s volume. The results exposed that LWM with grated EPS waste had greater physical and mechanical properties than with EPS beads because it has low void content and suitable distribution. In addition, mortar with 85% grated EPS had similar properties than that with 75% EPS beads. Accordingly, EPS should be grinded to increase its volumetric percentage in the mixture. Also, electron microscopy was used as an integral technique to study surface morphology between mortar components and the EPS.

An Experimental Investigation On Light Weight Concrete By Uisng Expanded Polystyrene Beads (Eps)

An Experimental Investigation On Light Weight Concrete By Uisng Expanded Polystyrene Beads (Eps)

Numerical Evaluation on Thermal Performance of 3D Printed Concrete Walls: The Effects of Lattice Type, Filament Width and Granular Filling Material

Three-dimensional concrete printing (3DCP) is of great interest to scientists and the construction industry to bring automation to structural engineering applications. However, studies on the thermal performance of three-dimensional printed concrete (3DPC) building envelopes are limited, despite their potential to provide a long-term solution to modern construction challenges. This work is a numerical study to examine the impact of infill geometry on 3DPC lattice envelope thermal performance. Three different lattice structures were modeled to have the same thickness and nearly equal contour lengths, voids, and insulation percentages. Additionally, the effects of filament width and the application of granular insulating materials (expanded polystyrene beads and loose-fill perlite) were also studied. Finally, the efficacy of insulation was established. Results show that void area affects the thermal performance of 3DPC envelopes under stagnant air conditions, while web length, filament width, and contact (intersection) area between the webs and face shells affect the thermal behavior when cavities are filled with insulating materials due to thermal bridging. The thermal efficiency of insulation, which shows the effective use of insulation, varies between 26 and 44%, due to thermal bridges.

Research on the mechanical properties of EPS lightweight soil mixed with slag.

Expanded polystyrene (EPS) bead lightweight soil composites are a new type of artificial geotechnical material with low density and high strength characteristics that can be widely used in engineering projects. To promote the wide application of EPS bead lightweight soil in engineering, when slag is used to replace part of the cement as a binding agent, it can better improve the effect of soil and reduce engineering costs. The mechanical properties of EPS lightweight soil mixed with slag were analyzed by conducting an unconfined compressive strength (UCS) test and triaxial test on lightweight soil with different EPS bead contents and slag contents. The particle sizes of the EPS beads are 1~3 mm, the EPS contents are 1%, 2%, 3%, and 4%, and the slag-cement composite binding agents are 10%, 15%, 20% and 25%. The results show that the UCS decreases significantly with increasing EPS bead content at different EPS bead contents and slag contents; the UCS of the specimen with 30% slag content is the largest; and the UCS of lightweight soil without slag is comparable to that of lightweight soil with a slag content of approximately 60%. The peak stress in triaxial increases with increasing confining pressure, and the modulus of deformation decreases linearly with increasing EPS bead content. the slag-cement composite binding agent has a significantly better reinforcing effect than single mixed cement. The stress‒strain curves of EPS lightweight soil mixed with slag exhibits hardening and softening characteristics. EPS bead content and slag content determine the stress‒strain characteristics of the EPS lightweight soil mixed with slag. The macromechanical properties based on the microscopic mechanism of the EPS lightweight soil mixed with slag shows that different slag contents affect the failure pattern of EPS lightweight soil mixed with slag. The research results can provide a reference for engineering design and application.

An experimental investigation of the mechanical characteristics and drying shrinkage of a single-size expanded polystyrene lightweight concrete reinforced with waste plastic fibres

This research focuses on developing single-size expanded polystyrene (EPS) lightweight concrete reinforced with waste plastic fibres (WPFs) and evaluating its mechanical characteristics and drying shrinkage. An experimental investigation of two groups of concrete mixtures was conducted. The first experiment involved the partial substitution of the coarse aggregate volume with 5%, 10%, 15%, 20%, 25%, and 30% EPS beads. The second investigation involved six different volume fractions Vf of waste plastic fibres. A comprehensive test programme was implemented to evaluate these mixtures by measuring compressive strength, flexural strength, drying shrinkage, ultrasonic pulse velocity, and water absorption. The incorporation of EPS in the concrete mixtures in Group 1 resulted in reduced compressive strength and flexural strength at all ages. The drying shrinkage of the concretes in Group 1 increased with the proportion of EPS aggregate. The addition of waste plastic fibres to the concrete mixes in Group 2 improved the compressive strength for volumetric fractions of WPFs between 0% and 1%, but greater proportions of volumetric fibres up to 1.5% decreased the compressive strength. The inclusion of WPFs reduced the drying shrinkage of the Group 2 concretes at volume fractions between 0.25% and 1.25% compared to that of the reference mix (M8). In general, drying shrinkage developed rapidly in concrete specimens with added EPS and WPFs tested at 40–60 days and became more stable after 60 days.

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.

Meso-scale deformation and strength mobilization mechanisms of EPS composite soil

Expanded polystyrene (EPS) composite soil is composed of two solid constituents (cemented soil and EPS beads), which together with the inter-constituent interfaces form a unique mesoscopic structure. The macroscopic behavior of EPS composite soil has been widely investigated so far, but the focus has seldom been put on the meso-scale mechanisms behind the macroscopic deformation features and strength mobilization processes. In this study, systematic experiments and refined numerical simulations are utilized to examine the meso-scale mechanical responses of EPS composite soil under triaxial compression to reveal the associated mechanisms. Here, meso-scale is a scale smaller than a sample scale but larger than an EPS bead scale. First, the mechanical behavior of cemented soil, EPS material and their interface is obtained in experiments; their constitutive models are formulated, and the model parameters are calibrated based on experimental results. Then, experiments and refined numerical simulations of triaxial compression on EPS composite soil are performed. It is found that the rich macroscopic mechanical behavior of EPS composite soil has a mechanical source (contrast in mechanical behavior between EPS and cemented soil) and a geometric source (non-uniform distribution of EPS beads). The mechanical source leads to highly non-uniform stress and strain distributions within an EPS composite soil. The geometric source causes strain localization in zones with local concentration of EPS beads, leading to three macroscopic deformation modes, i.e., overall shear localization, local lateral expansion, and overall uniform expansion. In strength mobilization, cemented soil matrix first mobilizes its strength because it takes most of the load and contributes much to deformation at the early stage of triaxial compression. EPS beads are later progressively involved in the overall load bearing and deformation of the EPS composite soil sample. EPS beads make more contribution to stress than to strain due to its soft nature.

Influence of Using Expanded Polystyrene Beads on the Density and Compressive Strength of Hardened Concrete

Influence of Using Expanded Polystyrene Beads on the Density and Compressive Strength of Hardened Concrete

Influence of Temperature on Shear Behavior of Lightweight Reinforced Concrete Beams Using Pozzolana Aggregate and Expanded Polystyrene Beads

The innovation inherent to employing expanded polystyrene (EPS) beads lies in its transformative impact on traditional concrete practices. Through the incorporation of EPS beads in concrete mixtures, a novel approach emerges that significantly alters the material’s characteristics, and opens up new avenues for construction and design. Studying the shear behavior of RC beams made with EPS beads is essential for advancing knowledge, improving design practices, ensuring structural integrity, and promoting the effective and responsible use of innovative materials in construction. This research experimentally investigated the effect of using EPS beads and pozzolana aggregate (PA) on the shear behavior of the RC beams. A total of 27 simply supported rectangular beams were cast, using three novel distinct mix designs, and were subjected to two-point load testing until failure. These three mixes were categorized as follows: a control mix, a mix with only EPS, and a mix with EPS, along with an additive. The ultimate failure load was experimentally recorded for all specimens, and the influence of the temperature (300 °C and 600 °C) on the RC beams made with EPS was examined. The findings revealed a reduction in the concrete compressive strength and density in the beams containing EPS and EPS with superplasticizers of (21.7%, 24.9%) and (11.3%, 16.2%), respectively. Additionally, EPS played a significant role in diminishing the ultimate shear capacity of the beams, compared to the control beams, by about 19.4%. However, the addition of a superplasticizer along with the EPS helped to maintain the beam capacity, to some extent. Conversely, the beams exposed to a temperature of 300 °C exhibited an almost similar capacity to that of the control beams without heating. Nevertheless, at 600 °C, the beams displayed a noticeable decrease in the ultimate load capacity, compared to the unheated control beams.

Novel preparation method and fire performance study of EPS composites based on calcium sulphate hemihydrate

A novel approach was used to prepare a new expanded polystyrene (EPS) composite based on calcium sulphate hemihydrate that significantly improves its fire performance. Negative pressure was applied to open cavities between the EPS beads and promoted the absorption of flame retardant slurry. Three fire retardant EPS (FR-EPS) composites with different densities were obtained. Although, a large number of inorganic additives were added, causing the increase in thermal conductivity to 0.043–0.045 W/(m∙K) and water absorption to 4.7–5.8%, the properties remained within an acceptable range. The results of limiting oxygen index (LOI), UL-94 vertical burning and Cone Calorimeter tests revealed that the FR-EPS1 increased LOI from 18.1% to 35.8%, achieved UL94 V-0 grade, decreased PHRR from 384.12 to 81.39 kW/m2, and reduced PSPR from 0.159 to 0.014 m2/s. With the continued increase of sample density, the measured LOI was further improved, while heat release and smoke production were better suppressed. TG results, and carbon residue after burning indicate that the endothermic dehydration reaction of calcium sulphate dihydrate and the physical barrier effect of the carbonaceous layer contribute to the extraordinary flame retardancy and smoke suppression of the FR-EPS composites.

Application of Stochastic Finite Element Modeling to Reinforced Lightweight Concrete Beams Containing Expanded Polystyrene Beads

Limited investigations have evaluated the effect of expanded polystyrene (EPS) beads on the structural lightweight concrete properties. EPS offers many features compared to natural or artificial lightweight aggregates including the elimination of aggregate saturation prior to concrete batching, ability to be fabricated on site, consistency in size and quality, and reduced cost. The main objective of this paper is to assess the suitability of finite element (FE) modeling based on deterministic and stochastic approaches to predict the shear strength behavior of reinforced concrete (RC) beams containing EPS additions. Test results showed that the experimental load-deflection properties recorded at failure can be well reproduced using both FE approaches. Nevertheless, the damaged-zone distribution and crack patterns that occur during the loading stages of RC beams cannot be approximated using the deterministic FE approach. In contrast, the stochastic method was quite suitable as it accounted for the concrete heterogeneity and altered spatial mechanical properties (such as compressive strength, splitting tensile strength, and Young’s modulus) due to EPS additions. Such data can be of interest to civil engineers seeking to predict the failure patterns and performance of structural lightweight members while reducing the time and resources needed to account for the concrete’s strength variability during experimental testing.

Engineering properties and sustainable applications of pond ash geomaterial incorporating expanded polystyrene beads

This study investigates the engineering behavior of a sustainable geomaterial called Pond Ash Geomaterial (PAGM), made by blending Expanded Polystyrene beads (EPS) with pond ash and cement as a binding agent. The effects of EPS density, beads content, and cement content on the density, compressive strength, and elasticity modulus of PAGM are analyzed. The results show that PAGM with low-density and low-content EPS can achieve similar properties to high-density and high-content EPS PAGM. Based on these findings, design charts are proposed that can facilitate the guidelines for the application of PAGM on-site. The study highlights the suitability of PAGM as a lightweight filling material that can reduce environmental impact and be a cost-effective alternative to EPS geofoam blocks. Predictive models are developed for determining the engineering characteristics of the PAGM. Overall, the use of PAGM as a building material has practical implications for sustainable construction practices, as it utilizes an industrial byproduct, reduces waste, and can be used in a range of applications.

Punching shear capacity of expanded polystyrene (EPS) lightweight concrete flat slabs without shear reinforcement

This work presents an experimental and theoretical study on the punching shear behavior of Lightweight Concrete Slabs. Lightweight obtained using Expanded polystyrene (EPS) beads as partial coarse aggregate’s replacement, without adding supplementary bonding additives, to reduce concrete density from 2400 to 1800 kg/m3. The EPS content, concrete strength and column aspect ratio were test parameters. Five groups of concrete prepared by partially replacing natural coarse aggregate with 0%, 10%, 20%, 30% and 40% (by volume) of EPS balls. Ten reinforced concrete slabs without shear reinforcement with a monolithic column were tested under concentric loading. The study aimed to examine the effect of the EPS on the density and compressive strength of concrete and eventually on the flat slabs punching capacity. Five series of mixtures identified and compared with conventional normal weight concrete. Results showed that with increasing EPS content, rate of reduction in concrete strength is faster than the reduction in concrete density. Also, showed that the failure base area increased while the concrete density decreased, this yielded a higher punching capacity compared to rate of decrease in the concrete strength. International standards models showed overestimation of punching shear capacity and didnot reflect the reduced concrete strength action of lightweight concrete.