건자재 산업 동향 및 전망(1) - 레미콘(ready mixed concrete) -

최민수(M.S.Choi) 한국건설산업연구원 2004 한국건설산업연구원 연구보고서 Vol.2004 No.1

The primary purpose of this study is to analyze the market structure and consumption behavior of ready-mixed concrete as well as propose various short and long-term countermeasures concerned with technological development, cost saving and stabilization of supply. The ready-mixed concrete industry in Korea, introduced in 1965, has maintained a important role as a construction material industry. The growth of the industry has been influenced by the development of construction industry. In the 1990s, the ready-mixed concrete industry made rapid progress due to numerous construction projects, especially 2million houses project and subway constructions. Under the IMF crisis, started from 1997, the demand for ready-mixed concrete has rapidly decreased. However, after 2000, the ready-mixed concrete industry has begun a strong rebound due to the reconstructions of superannuated houses and the development of infrastructure. According to a recent survey on the ready-mixed concrete industry, the maker's annual production capacity increased to 324 million m' in 2002 from 124 million ㎥ in 1990. The domestic consumption for ready-mixed concrete has increased to 137 million ㎥ in 2002 from 58 million ㎥ in 1990. Since the latter half of the 1990s, the industry has emphasized cost saving against soaring cement price and continuous buyer's market in construction industry. In order to decrease the production cost, numerous slag and fly ash, which IS the by-products of steel mill and thermoelectric power plant, are widely used to replace a part of cement in production of ready-mixed concrete. In general, the construction frame structure IS, for the most part, steel reinforced concrete structure in Korea. Therefore, in Korea, 82 percent of cement consumption is used to produce ready-mixed concrete in 2002. However the ratios of most European countries record around 50 percent, which is caused by the development of wooden housing or prefabricated building methods. Also, the consumption of ready-mixed concrete per head reached 2.9㎥/person as well as the production of ready-mixed concrete per one factory reached 184 thousand ㎥ in 2002. The volume is approximately three times as large as that of Japan, United states and European countries. Furthermore the input of ready-mixed concrete per 1 billion won(1995 constant market price) has increased to 1,824㎥ in 2002 from 799㎥ in 1985. Due to the increase of high-rise or long span buildings, the consumption of ready-mixed concrete with high strength and high slump has increased. In aspect of raw materials, the consumption of blended or special cement, for example, slag cement, ultra high-early-strength cement, and rapid hardening cement, has increased to reduce a construction period and retrench the manufacturing cost. As aggregates for ready-mixed concrete, the consumption of sea sand and crushed sand has increased in replacement of river sand. On the other hand, long-term prospects for the ready-mixed concrete industry in Korea are expected to be bright because of continuously increasing construction demand. Ready-mixed concrete business circles forecast that domestic demand will continue 150 million ㎥ to 2010. Therefore the stable supply of ready-mixed concrete will be remained as important as ever in future. However, the shortage of aggregate is as serious as ever. In order to stabilize the supply of aggregate, a large-scale development of land aggregate, rock crushes, and sea sand In EEZ should be requited. Global sourcing of raw materials should be enlarged to reduce the manufacturing cost. However, in order to enlarge the imports, it is important to construct a stable supply chain against a sudden short supply caused by unusual change of the weather or unavoidable circumstances of exporters. The investment of technological development sectors in the ready-mixed concrete industry has concentrated on the high strength or high performance concrete, cementitious materia

건설자재의 투입 구조 및 원단위 분석

최민수(M.S. Choi),권오현(O.H. Kwon) 한국건설산업연구원 2006 한국건설산업연구원 WORKING PAPER Vol.2006 No.2

  The objective of this study is to suggest the inputs of construction materials per unit output of construction investment or building permit area(㎡), and to analyze input structure of construction materials based on statistics regarding consumption of construction materials, the amount of construction investment, and input-output tables published by the bank of Korea.<BR>  Based on the research results, it was revealed that ready-mixed concrete was the most massively used in construction works, which was inputted 4,400 billion won"s worth in 2000 and made up 11.8% of total input of construction materials. Subsequently, structural metal products that covered 10.5%(3,900 billion won) and steel bar that made up 7.0%(2,500 billion won) had high relative importance.<BR>  Input of cement per unit of construction investment (2000 constant price) had decreased by 5.2 percent from 501 ton/billion won during 1996-1999 to 475 ton/billion won during 2000-2005. The reason is because substitutive materials for cement such as fly ash or blast furnace slag had increased dramatically since 2000 and will be increased for the present. Moreover, input of plywood has been decreased owing to the popularization of systemized sheathing boards made of steel or plastic as well as the input of hume pipe has declined owing to the decrease of drainage works.<BR>  On the other side, inputs of tile and toilet stool per unit of construction investment have increased. The reason is because the floor plan that adopts two bathrooms in a house has been popularized and demand for remodeling housing has increased dramatically.<BR>  Basic unit of the major construction materials for structural frame such as steel bar, ready-mixed concrete, and aggregate have increased around 10%, the reason is because the regulation for earthquake-proof structural design has been enforced as well as underground parking area has been generalized in apartment houses. Also, input of concrete pile per unit of construction investment has been greatly increased thanks to the activation of redevelopment or reconstruction projects and high-rise apartment houses. Inputs of gypsum board products have been increased about 30% thanks to the increase of floor designs for skeleton and infill housing.<BR>  Finally, input of construction materials per 1 billion won of construction investment based on current price of 2005 were estimated 467 tons of cement, 86 tons of steel bar, 1,085㎥ of ready-mixed concrete, 1,938㎥ of aggregate, 26.4 tons of H-beam. Moreover, input of construction materials per 1 thousand ㎡ of building permit area were estimated 230 tons of cement, 522 tons of steel bar, 589㎥ of ready-mixed concrete, 16.7 tons of H-beam, and so forth.<BR>  The input per unit of construction investment suggested from this study can be used for government or construction companies to forecast the yearly demand of construction materials or to estimate roughly the amount of construction materials needed in a construction project.

기술제안입찰제도의 발전 방향

최민수(M. S Choi) 한국건설산업연구원 2009 한국건설산업연구원 연구보고서 Vol.2009 No.4

제1장 서 론 - 현행 공공공사의 입찰 제도는 대부분 가격 위주의 평가 방식을 채택하고 있으며, 이러한 문제점을 인식하여 정부에서는 건설업체간 기술 경쟁을 촉진하기 위하여 최근 ‘기술제안입찰제도’를 도입한 바 있음. - 정부에서는 국가경쟁력강화위원회가 마련한 『건설산업선진화방안』을 토대로 기술 위주의 입찰 방식을 강화하기 위하여 기술제안입찰을 확대 적용하는 방안을 검토하고 있음. ·그런데 동 제도를 확대 시행하기 위해서는 지금까지 적용 사례가 미흡하기 때문에 운용 과정에서 상당한 시행착오를 겪을 우려가 있음. - 본 연구에서는 정부 예산 절감 및 기술 경쟁의 확대라는 정책 목표를 성공적으로 달성하기 위해서 일본의 종합평가낙찰제와 비교 분석을 통하여 국내 기술제안입찰 제도의 발전 방안을 제시하고자 함. 제2장 기술제안입찰제도의 현상(現狀) 및 논점 1. 개요 및 도입 경과 - 기술제안입찰이란 발주자가 미리 결정한 공사계획 및 설계 범위 안에서 시공사가 시공실적 등을 제시하는 기존 방식과 달리, 발주기관이 교부한 실시 설계도서와 입찰안내서에 따라 입찰자가 스스로 설계를 검토한 후 시공 계 획, 공사비 절감 방안 및 공기(工期) 단축 방안 등을 제안하고, 이를 심사하여 낙찰자를 결정하는 방식임. - 기술제안입찰 방식은 크게 1)기술제안형 입찰 방식과 2)설계공모·기술제안형 입찰 방식으로 나눌 수 있음. ·기술제안형 입찰 방식은 발주기관이 교부한 실시설계도서를 검토한 후, 입찰자가 기술제안서를 작성하여 입찰서와 함께 제출하는 방식으로서, 설계가 완료된 상태에서 부분적인 설계 대안이나 시공법 등에 대한 기술제안을 받아 기술력을 평가하는 방식을 말함. ·설계공모·기술제안형 입찰 방식은 발주기관이 설계 공모 등에 의하여 작성된 기본설계도서 및 입찰안내서에 따라 입찰자가 기술제안서를 작성하여 입찰서와 함께 제출하고, 낙찰자가 실시설계 및 시공을 담당하는 방식을 말함. - 정부에서는 2007년 9월 『국가계약법』시행령을 개정하여 기술제안입찰 제도를 도입하였고, 『지방계약법』시행령도 2007년 9월 개정되어 기술제안입찰 제도가 도입되었으며, 2008년 행정도시 정부청사 1단계 1구역 건립 공사에 처음으로 기술제안입찰이 시범 적용된 바 있음. 2. 기존 입찰 제도와 기술제안입찰의 비교 1) 기존 입찰 제도와의 비교 - 기술력을 평가하는 방식으로서 적격심사낙찰제의 경우, 시공경험, 기술능력, 경영상태, 신인도를 PQ점수로 평가하고, 최저가낙찰제에서는 저가심의를 통하여 신기술이나 신공법의 도입에 의한 공사비 절감 여부를 심사하고 있음. ·기술제안입찰에서는 PQ심사 결과를 반영하지 않고, 기술제안 내용을 심사하여 입찰에 반영하는데, 기술제안서의 평가 항목은 공사비 절감 방안, 생애주기비용 개선 방안, 공기 단축 방안, 공사관리 방안, 산출내역의 적정성 등 5개 항목임. - 입찰 방식은 적격심사낙찰제와 최저가낙찰제의 경우, 단가형 내역입찰을 활용하고 있으나, 기술제안입찰에서는 창의적인 VE기법 등 공사비 절감 방안을 제안할 수 있도록 입찰자가 직접 물량을 산출하고, 단가를 산출하여 입찰하는 ‘순수내역입찰’ 방식을 적용하고 있음. 2) 기술제안입찰과 대안입찰(alternative bid)의 비교 - 기술제안입찰은 기본적으로 대안입찰과 유사한 성격을 갖고 있으나, 대안입찰은 해당 프로젝트의 실시설계와 내역서 산출이 완료된 시점에서 입찰을 실시하는 반면, 기술제안입찰은 소위 순수내역입찰로서, 실시설계는 완료되었으나 내역서가 작성되지 않은 상태에서 입찰이 실시됨. ·또한, 대안입찰은 주로 설계 대안의 제시에 중점이 두어지나, 기술제안입찰은 공법 개선이나 원가절감 제안 등에 중점이 두어지는 특징이 있음. 3) 설계공모·기술제안입찰의 비교 - 설계 분야에서 경쟁이 이루어진다는 유사성이 있으나, 설계시공일괄입찰은 기본설계 단계에서부터 입찰자가 설계 업무를 담당하지만, 설계공모·기술제안입찰에서는 발주자가 제시한 기본설계 하에서 입찰자가 실시설계를 담당한다는 점에서 근본적인 차이점이 존재 ·또한, 설계시공일괄입찰 방식은 주로 설계 분야를 중심으로 심의가 이루어지나, 설계공모·기술제안입찰에서는 기본설계가 완료된 상태이므로 기술제안에 중점을 두어 심의가 이루어짐. 3. 기술제안입찰제도의 논점 - 그동안 시범사업 결과를 토대로 발주자, 건설업체 등에서 제기하고 있는 문제점으로는 다음과 같은 사항을 들 수 있음. 1) 기술제안입찰이 턴키공사와 유사한 흐름으로 낙찰자를 선정하기 때문에 대형 업체가 유리할 것으로 인식하는 경향이 높음. 2) 입찰에서 탈락한 업체에 대하여 기술제안서 작성 비용의 보상 문제가 대두되고 있음. 3) 건설회사에서는 영업팀, 견적팀, 설계VE팀, 시공기술팀 Popular opinion in recent times has begun to place greater emphasis on a tenderer’s technological capability rather than the tendering price in the tendering of public construction work. Because the lowest-cost tendering processes and procedures for screening eligible tenderers, which are currently widely adapted in Korea, are centered around only the tendering price, such processes are even termed ‘happy-go-lucky tendering methods’ such a situation calls for an improvement in these processes. Technical proposal tendering processes, introduced in 2007, are expected to play a significant role in evaluating the technological capabilities of construction companies. The government plans to extend the technical proposal tendering method to the tendering of public construction projects. However, projects where this tendering process can be applied as well as related practical guidelines for the same are few. In the light of these circumstances, this study proposes some improvements and policy directions after examining the expected claims and institutional inertia in implementing technical proposal tendering processes and benchmarking foreign cases such as the synthetic evaluation tendering process of Japan. According to the results obtained from benchmarking foreign cases, it is expected that few great claims may arise at the stage of extending the technical proposal tendering method, the reason being that there is plenty of experience in the areas of ‘alternative plan tendering’ and ‘design and construction package tendering’. However, most construction companies fear that big companies may have too much of an advantage if the technical proposal tendering process is widely applied therefore, it is important to create favorable conditions for establishing a reciprocal, equal-competition environment between big and medium-sized companies. Technical proposal tendering processes should be applied initially to construction projects that need to promote technological competition and then extended gradually to all types of construction projects in the future. Moreover, technical proposal tendering processes can be implemented in the tendering of small or medium-sized construction projects, like the simplified type of synthetic evaluation tendering process employed in Japan. In other words, the technical proposal tendering process can be treated in the same manner as screening systems for selecting eligible tenderers in the tendering of small or medium-sized projects. However, technological competition between tenderers should be further intensified besides a simplified construction plan or cost-down proposal, there should be technical interviews with technical engineers who will participate in the project. On the basis of a comparison with the synthetic evaluation tendering process of Japan, this study suggests the following policy directions for improving the technical proposal tendering process of Korea: 1) In order to promote the application of new technologies or new construction methods, premium points need to be added to a technical proposal so that even if the project construction cost increases, the grade of quality or performance will be far more enhanced. 2) Considering that unreasonable shortening of the construction period can lead to deteriorated quality and increased workplace accidents, the construction period needs to be curtailed through a profit-sharing clause during the construction phase rather than giving premium points to a shorter-construction period proposal during the tendering stage. 3) In order to evaluate the capability of technical engineers in substance, rather than evaluating possessed whole engineers, a new evaluation item that will assess engineers who will eventually participate in the project should be introduced. Then, the capability of the participating engineers should be evaluated through an appraisal of their work experience and past performance, including an interview

STAR-CCM+의 분산 다상 모델을 이용한 결빙현상 해석

최민수(M S. Choi),진봉용(B Y. Jin) 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.5

외란 관측기를 이용한 EHA 의 압력 직접 제어

송우근(W. K. Song),한창수(C. S. Han),전병찬(M. S. Choi),장재호(J. H. Jang),박상신(S. S. Park),최민수(M. S. Choi) 한국정밀공학회 2016 한국정밀공학회 학술발표대회 논문집 Vol.2016 No.5월

PAI 바인더 및 PTFE 윤활제를 활용한 고체윤활코팅의 내마모성 향상

이경재(K.J. Lee),최민수(M.S. Choi ),고재섭(J.S. Ko ),권혁우(H. Gwon ),민준원(J.W. Min) 한국자동차공학회 2017 한국자동차공학회 지부 학술대회 논문집 Vol.2017 No.6

STAR-CCM+를 이용한 선박 형상 최적화 시스템 구축 및 저항성능 개선에 관한 수치해석 연구

김병재(B. J. Kim),이종현(J. H. Lee),박동우(D. W. Park),전제형(J. H. Jun),최민수(M. S. Choi) 한국전산유체공학회 2023 한국전산유체공학회 학술대회논문집 Vol.2023 No.10