De facto standards can be divided into the U.S. group standards' and 'forum and the consortium standard. mainly applies to high-tech industry forums, and a consortium standard of the industry given the nature of the standard are frequently revised, the country Due to the introduction of standard time. Economic loss to consider when in reality, the introduction of national standards of the United States is limited to the desirable standard, and the fact the actual award of standards, national standards, or if you want to introduce standard, each of depending on the type of attitude and strategy for standards by category, based on the characteristics of each body strategy and are needed. Through this study on utilization of de facto standards for national standards, it is researched that major de facto standards bodies status and domestic industrial fields which need utilization of de facto standards for national standards. Through overseas Case, effective usage of de facto standards will be obtained.

De facto standards can be divided into the U.S. group standards' and 'forum and the consortium standard. mainly applies to high-tech industry forums, and a consortium standard of the industry given the nature of the standard are frequently revised, the country Due to the introduction of standard time. Economic loss to consider when in reality, the introduction of national standards of the United States is limited to the desirable standard, and the fact the actual award of standards, national standards, or if you want to introduce standard, each of depending on the type of attitude and strategy for standards by category, based on the characteristics of each body strategy and are needed. Through this study on utilization of de facto standards for national standards, it is researched that major de facto standards bodies status and domestic industrial fields which need utilization of de facto standards for national standards. Through overseas Case, effective usage of de facto standards will be obtained.

The signal characteristic of radar wave on concrete decks is determined by the attenuation of the radar due to the conversion of EM(Electromagnetic) energy to thermal energy through electrical conduction, dielectric relaxation, scattering, and geometric spreading. In this study, it is found that the attenuation of radar signal received on top rebars in bare deck concrete with 2 way travel time shows a general decreasing linear trend because of its same relative permittivity and conductivity. The radar signal after depth-normalization, can then be interpreted as being principally influenced by the content of chlorides penetrating cover concrete, which caused corrosion of rebars in bridge decks.

It is known that cement, when mixed with wood chip, may face problems in hardening depending on the type of wood.This study examined the wood chip pretreatment effect of the method of soaking fine wood chip in 100oC water andthen drying it and the effect of hardening accelerator on the setting time, strength and thermal conductivity of normalconsistency wood chip mortar with a flow value of approximately 110%. Mortar experiment showed that use of woodchip caused the water content required to obtain the same flow value to increase and the setting time to be overly delayed.It was shown that water treatment of wood chip in boiling water to solve such problem was not so meaningful in normalconsistency wood chip mortar but that use of hardening accelerator was more effective in solving retardation of settingand improving compression strength and specific strength.

In order to utilize waste wood chip for pavement, a polyurethane resin that is both eco-friendly and suitable for bindingwood chip was developed as the binder, and workability was examined through laboratory experiment for characteristicsof waste wood chip mixture using the polyurethane resin and through test pavement on the field. The new resin was aVOC reduction type free from plasticizer and solvent classified as endocrine-disrupting chemicals and environmentalhazardous substances, and NCO equivalents were set at 8, 9, 10 and 11% by modifying the polyisocyanate-polyol ratio.Laboratory experiment showed that polyurethane resin with NCO equivalent of 9% and 10% had excellent characteristicsas binder for waste wood chip. In the field experiment applying waste wood chip and polyurethane resin in the massratio of 1:0.8, tensile strength of the pavement system was about 30% higher than that using polyurethane resin currentlybeing sold, and permeability coefficient and elasticity thereof were the same as that using the resin currently being sold.Also, examination of compaction methods for waste wood chip pavement system showed that non-heating hand rollerand compactor had the problem of the “waste wood chip - resin mixture” sticking to the roller during the compaction but that heating hand roller had excellent workability and could achieve good planation surface relatively easily.

본 연구는 폐목재칩과 기존에 시판되고 있는 우레탄 수지를 결합재로 사용하여 표층재료로 한 폐목재칩 보도포장에 관한 것으로 시간경과에 따른 포장체의 물성변화와 유지보수방안을 검토하였다. 사용 재료로서 폐목재칩은 건설현장에서 수거된 폐목재를 분쇄한 것, 벌목 시 발생하는 나무뿌리를 포함한 임목폐기물를 분쇄한 것 및 장방형으로 분쇄한 소나무 임목부산물을 체 크기 10 mm체로 쳐서 통과시킨 것을 다시 3 mm 체로 쳐서 그 위에 잔류된 것을 사용하였으며, 우레탄수지는 국내 K사의 1액 상온 습기 경화형을 사용하였다. 폐목재칩과 우레탄수지의 배합은 질량비 1:0.8로 하였으며 시공 직후 및 1년과 2년경과 후 그의 표면상태, 투수성, 탄력성 및 인장강도를 검토하였다. 투수계수는 시간경과에 따라 다소 감소하는 경향이었으나 그 값은 투수성 포장의 요구조건을 만족하는 범위 이내이었으며, GB 및 SB계수로 측정한 탄력성은 시간경과에 따라 큰 변화를 나타내지 않았다. 그러나 포장체의 인장강도는 시공직후에 비해 시공 1년 및 2년 후 각각 50% 및 60% 정도 감소되었으며 나무뿌리를 포함한 임목폐기물을 사용한 경우 이외에서는 폐목재의 이탈이 증가하는 것으로 나타났다. 현장실험결과 1년경과 시마다 폐목재칩 보도포장의 표면에 1 m2당 0.5 kg의 우레탄 수지를 도포함으로써 폐목재칩의 이탈을 방지할 수 있었으며 표면강도 또한 개선되는 것으로 나타나 경과시간에 따른 우레탄 수지의 추가 도포에 의한 유지보수는 폐목재칩을 활용한 보도포장의 내구성을 증진시키는 좋은 방법으로 평가되었다.

폐목재칩과 우레탄수지 바인더를 결합하여 보도포장의 표층재료로써 활용하기 위한 연구의 일부로 다짐방법에 대한 검토와 보행자의 선호도를 조사하였다. 폐목재칩을 활용한 친환경 보도포장의 현장시공에서 사용된 다짐장비는 가열식 핸드롤러(무게 30 kg, 온도 200 ~ 250℃), 비가열식 철제 핸드롤러(무게 45 kg) 및 콤팩터(출력 5HP 3600 rpm, 무게 88 kg)의 3종류를 대상으로 작업의 용이성, 보도표면의 평탄성, 인장강도, 투수성 및 탄력성을 검토하였다. 보도포장 표층다짐 시 사용된 다짐장비 중 비가열식 핸드롤러 및 콤팩터는 다짐과정에서 폐목재칩과 수지 혼합물이 롤러에 부착되거나 양호한 평탄성을 얻기 어려운 문제점이 있었으며, 가열식 핸드롤러의 경우에는 시공성이 우수하고 양호한 평탄면을 얻을 수 있었다. 폐목재칩 결합용 우레탄 수지를 새로 개발하고 이를 결합재로 하여 폐목재칩과 우레탄수지를 질량비 1:0.8로 하였을 때 시공 후의 보도포장체의 물성은 다짐방법에 따라 다르나 대체로 인장강도 1.0 MPa, 투수계수 0.5 mm/sec, GB와 SB계수 모두 30% 전 후로 측정되었다. 사용자의 설문조사에서는 보도포장체의 종류별로 안전성, 보행감, 주변환경과의 조화, 친환경성, 미끄럼 저항성 등의 항목에 대하여 평가하도록 하였으며, 폐목재를 활용한 친환경 보도포장은 보행감 및 주변환경과의 조화항목에서 가장 높이 평가되었으며, 기타 항목에 있어서도 우수한 것으로 평가되었다.

The physical properties of sidewalk pavement material made by combining rectangular chips with urethane resin were reviewed through both an indoor test and an on-site test. To obtain the chips, forest tree by-products were crushed and then passed through a 10mm sieve. The materials that remained in the 2.36 mm sieve are the above mentioned chips. For the indoor test, the mixing ratios of urethane resin to chips, by mass, were set as 30%, 40%, 50%, 75% and 100%, respectively. Then, the mixture obtained by mixing with forced mixing type mixer was formed in an iron mold. Tests for tensile strength, elasticity and permeability coefficient were performed 7 days after forming. For the on-site test, the cross-section of the sidewalk pavement material consisted of sand filter layer, crushed stone subbase, permeable concrete base and surface layer of the forest tree chip mixture. For the surface layer, the mass ratios of urethane resin to the forest tree chip were determined to be 40%, 60% and 80%, respectively. The physical property test like the one performed in the indoor test and the skid resistance test was performed over 7 days after the completion of trial construction. According to the result of the tests, the tensile strength, GB/SB coefficients and permeability coefficient were 0.1 to 0.7MPa, 15 to 43% and 0.3 to 0.5mm/sec, respectively, depending on the mixing ratio. In addition, the skid resistance coefficient was 75BPN with the mass ratio of the urethane resin to the forest tree chips of 80%. Furthermore, it was found through the on-site test that a pavement surface with excellent surface smoothness could be obtained through the application of a construction method using an electric heat roller. It was also confirmed that the mixing ratio of urethane resin to forest trees chips needed to be 60% or more.

목재칩과 우레탄 수지를 결합한 혼합물을 보도포장의 표층재료로서 사용하였을 때, 기상조건에 따른 물성 변화를 알아보기 위한 실험을 실시하였다. 시험체는 다짐기구의 종류에 따라 다짐횟수 및 가압시간을 변화시켜 폭 410mm, 길이 670mm, 두께 40mm의 크기로 제작하였으며, 7일 양생 후 단위용적질량을 측정한 다음 폭 30mm의 크기로 절단하여 인장강도 시험을 실시하였다. 기상조건에 따른 물성 변화를 알아보기 위한 실험은 강우 환경과 해수 환경에서의 실험, 동결융해실험 및 내후성 실험으로 구분하여 실시하였다. 목재칩과 우레탄 수지를 결합한 혼합물에 대한 실험결과, 인장강도는 강우 환경에서 상당한 감소를 나타냈으나 이러한 강도 저하는 해수 환경 및 동결융해 시에 더욱 심화되지는 않는 것으로 나타났다. 또한 제논 아크에 노출시킨 경우 시험체의 인장강도가 변화하였는데 이는 목재칩과 우레탄 수지의 혼합물이 햇빛에 의해 다소 열화될 수 있음을 나타낸 결과로 판단된다.