• Proceedings of the Korean Institute of Building Construction Conference
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• 2002.05a
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• pp.91-96
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• 2002

This study is to investigate the insulation performance of lightweight concrete using recycled lightweight aggregate, to develop lightweight concrete products which have an excellence on the insulation performance are satisfied with properties of building materials. As a result of this study, recycled EPS aggregate is considered to have an independent pores which is closed by dense partitions. So, it is showed that the insulation performance of lightweight concrete using recycled EPS aggregate are excellent. Especially, in the case of lightweight concrete under conditions of replacement ratio over 100%, it is considered that insulation performance is very excellent as thermal conductivity is showed about 0.2kcal/mh$^{\circ}C$. According to considering the relation between ultrasonic pulse velocity, unit weight and thermal conductivity through the graph, the result of relation between ultrasonic pulse velocity, unit weight and thermal conductivity on the graph expressed their high interaction shown as direct proportion on the graph. So that it is possible to extract the insulation performance of lightweight concrete using recycled EPS aggregate by ultrasonic pulse velocity and unit weight.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.1
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• pp.35-39
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• 2017

We used a construction method using a CNC milling machine, where free-formed molds were made by cutting EPS (Expanded PolyStyrene) foam with the CNC machine, to build free-formed buildings. CNC milling is off-the-shelf technology that can easily cut EPS foam; however its production cost is too high and the time to manufacture an EPS mold is too long. This paper proposes a novel cutting machine with a fast and cost effective mechanism to manufacture EPS concrete molds. Our machine comprises a cutter and Cartesian coordinate type moving mechanism, where the cutter cuts EPS foam using a hotwire in the shape of '$\sqcap$' and is capable of adjusting its cutting angle in real-time while keeping its cutting width. We proved through cutting experiments on the CNC machine that cutting time was greatly shortened compared to the conventional method and that the resulting concrete mold satisfied manufacturing precision.

• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.35-39
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• 2008

This experimental study examines the applicability of polymer mortar permanent forms using a methyl methacrylate (MMA) solution of waste expanded polystyrene (EPS) to develop effective recycling processes for the EPS, referring to the flexural behavior of a polymer-impregnated mortar permanent form with almost the same performance as commercial products. An MMA solution of EPS is prepared by dissolving EPS in MMA, and unreinforced and steel fiber-reinforced polymer mortars are mixed using the EPS-MMA-based solution as a liquid resin or binder. Polymer mortar permanent forms (PMPFs) using the EPS-MMA-based polymer mortars without and with steel fiber and crimped wire cloth reinforcements and steel fiber-reinforced polymer-impregnated mortar permanent form (PIMPF) are prepared on trial, and tested for flexural behavior under four-point (third-point) loading. The EPS-MMAbased PMPFs are more ductile than the PIMPF, and have a high load-bearing capacity. Consequently, they can replace PIMPF in practical applications.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.793-798
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• 2003

The purpose of this study is to investigate the setting properties of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with waste EPS solutions which prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, the working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage of polystyrene mortars should be accomplished by adjusting EPS concentration of EPS solution and crosslinking agent content.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.102-103
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• 2020

Research for heat insulation of buildings is being carried out, in which a heat exchange barrier is used around the openings and balcony parts as a method for heat exchange blocks. However, the preparation for a fire is inadequate. In order to improve the EPS used as a heat exchange barrier in an attempt to solve this, there is a study on lightweight foamed concrete, but as the amount of EPS used for strengthening fire resistance increases, it becomes lower. There is no strength applied to buildings, and also. There is a limit to the amount of EPS used. In the study, we use oyster shells to secure the EPS replacement rate limit of lightweight Foamed concrete, and try to measure the change of physical properties depending on the unit cement content.

• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.207-215
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• 2002

This study is focusing on mixing the foamed concrete incorporated by waste expanded polystyrene(W-EPS), investigating the physical properties and offering a proper quality control method to the field engineers. Two types of W-EPS (type A and type B) were studied. Type A (B) had globular (crushed) shape and diameter of 3-5 (1-2) mm. The results show that the flow was suddenly reduced with increasing mixing quantity of two types, but it satisfies KS F 4039 until 60 ％ of mixing rate. In general, the absorption rate was suddenly reduced with increased mixing quantity of two types especially, in type A. Apparent specific gravity was 0.36∼0.53 and reduced with increasing mixing quantify of type A. But it increased in case of type B. Compressive strength and heat conduction rate increased with mixing with W-EPS than non-mixing W-EPS but reduced with mixing too much W-EPS. Based ong the results, it is believed that mixing with W-EPS can improve the recycle of industrial wastes and produce the high quality foamed concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.833-836
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• 2006

The purpose of study is to develope for lightweight concrete panel which have high quality with insulation performance of sound. The use of lightweight concrete products has been increased at a recently high structures. Also, the gathering of nature aggregate is limited, so that lack of fine aggregate is appearing. Statistical analysis is practiced on the properties of EPS concrete according to the variation of mix design. As a result saturated density is affected by amount of Bottom ash.Also compressive strength is affected by W/B ratio at the early age and amount of Bottom ash at the latter age.

• Steel and Composite Structures
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• v.34 no.4
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• pp.581-597
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• 2020

Light-Weight Concrete containing Expanded Poly-Styrene Beads (EPS-LWC) is an approved structural and non-structural material characterized by a considerably lower density and higher structural efficiency, compared to concrete containing ordinary aggregates. The experimental campaign carried out in this project provides new information on the mechanical properties of structural EPS-LWC, with reference to the strength and tension (by splitting and in bending), the modulus of elasticity, the stress-strain curve in unconfined compression, the absorbed energy under compression and reinforcement-concrete bond. The properties measured at seven ages since casting, from 3 days to 91 days, in order to investigate their in-time evolution. Mathematical relationships are formulated as well, between the previous properties and time, since casting. The dependence of the compressive strength on the other mechanical properties of EPS-LWC is also described through an empirical relationship, which is shown to fit satisfactorily the experimental results.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.54-60
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• 2004

This study deals with the setting behavior of polystyrene mortars using waste expanded polystyrene(EPS) solution-based binders. The binders for polystyrene mortars are made by mixing crosslinking agent with EPS solutions prepared by dissolving EPS in styrene. Polystyrene mortars are prepared with various EPS concentrations of EPS solutions and crosslinking agent contents, subjected to a dry curing, and tested for working life, peak exotherm temperature and 10h-length change. From the test results, He working lives of polystyrene mortars are shortened with raising EPS concentration of EPS solution and crosslinking agent content. Low-shrinkage or non-shrinkage polystyrene mortars could be obtained by adjusting EPS concentration of EPS solution and crosslinking agent content.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.425-428
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• 2003

This study deals with the mechanical properties of polymethyl methacrylate(PMMA) mortars without crosslinking agent. Waste expanded polystyrene(EPS) is used as a multifunctional admixture such as a thickener, a extender, a shrinkage reducing agent, a assistant to polymerization. PMMA mortars are prepared with various EPS contents of binder and subjected to a dry and a dry/heat combined curing, and tested for working life, flexural and compressive strengths. From the test results, the working life of PMMA mortars without crosslinking agent is shortened with raising EPS content of binder. The flexural and compressive strengths of the PMMA Mortars are decreased somewhat with increase in the EPS content. PMMA mortars with good mechanical properties could be manufactured without any crosslinking agent and their properties would be controled by adjusting EPS content of binder.