• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.141-147
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• 2017

The purpose of this study is to develop an inorganic filling adhesive using MKP and borax based on Dead-burn magnesia and fly ash. First, basic experiments was conducted to derive the proper addition rate of MKP. And this experiment was carried out according to addition ratio of borax. The test items are measured for pot life, flexural strength, compressive strength, adhesive strength, tensile strength, ratio of temperature change, ratio of hardening shrinkage, radon gas and formaldehyde emission. As a result, the proper addition rate of phosphate was 35%. The pot time is about 10minutes, 15minutes and 25minutes according to addition rate of borax. The flexural strength and compressive strength were obtained at 12hours for minimum flexural strength of 8.0MPa and minimum compressive strength of 31.0MPa. The tensile strength was the least 4.1MPa, and the ratio of hardening shrinkage was maximum 2.4% and ratio of heat change was maximum - 0.3%, which satisfied all of the quality standards of 'KS F 4923' (epoxy resin for repairing concrete structures). Both Radon gas and formaldehyde emission was not detected.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.4
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• pp.106-112
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• 2001

Recent advance in material technology has accelerated the development of high strength concrete using lightweight artificial aggregates. The lightweight concrete has many advantages that the reduction of dead loads and the increase in load capacity can offer. In this study the lightweight polymer concrete using unsaturated polyester resin and lightweight aggregate were prepared and tested for testing the physical and the mechanical properties. The compressive strengths of lightweight polymer concretes with apparent specific gravity for 1.32 to 1.78 were 250 to 470 kfg/cm$^2$ and flexural strengths were measured to be in the range of 1/3-1/4 of compressive strength.

• Journal of Conservation Science
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• v.34 no.1
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• pp.23-29
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• 2018

This study synthesized poly-urea and used it as a filler material for the restoration of porcelain. The synthesized poly-urea was manufactured as a resin and hardener mix that does not undergo contraction during curing, and is unfading. Given an adhesion strength of $180kg/cm^2$ and shearing strength of $200kg/cm^2$, the synthesized poly-urea exhibited the same efficacy as the epoxy putty currently sold in the market. Moreover, it also overcame the drawback of foaming encountered by urethane restoratives, which are a structurally similar type. The hardening time and pot life could also be controlled using additives. The poly-urea used for the restoration of modern artifacts presented a pot life of approximately one hour and took 12 h for complete hardening ($T_{90}$). When a $2{\times}2{\times}2cm$-sized test sample was added to xylene, poly-urea started to separate approximately two hours later and completed perfect pulverization within the solution 24 h later, demonstrating its reversibility. When directly applied to contemporary artifacts, it demonstrated the potential for restoration, as well as convenience and colorfulness.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.117-124
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• 2006

The effects of binder content and recycling mixed waste plastics(PA) content on the workability, work life and hardening shrinkage of fresh polymer concrete using mixed waste plastics are examined. As a result, the workability of the polymer concretes using mixed waste plastics tend to improve with increasing binder content, PA content and filler content. The work life of the polymer concretes using mixed waste plastics is shortened with an increase in the initiator content and curing temperature. The length change of the polymer concretes using mixed waste plastics tend to increased with Increasing binder content and PA content. The result of the present research is expected to make a contribution to the recycling of final mixed waste plastics and the continuing efforts for the development of use of the recycled products are thought to expand the horizon for the recycling of the final mixed waste plastics.