Algorithms for in-situ production layout of composite precast concrete members Won-Kee Hong, Goonjae Lee, Sungho Lee, Sunkuk Kim ⁎ Department of Architectural Engineering, Kyung Hee University, 1732 Deokyoungdaero, Giheung-gu, Yongin 446-701, Republic of Korea abstract article info Article history: Accepted 8 February 2014 Available online 2 March 2014 Keywords: Composite precast concrete In-situ production layout Mathematical model Algorithm Point-in-polygon In general, precast concrete (PC) construction is preferred to reduce construction time, improve the quality of buildings and reduce costs. This type of construction consists of in-plant or in-house production, transportation and on-site erection processes. However, the PC construction method based on in-plant production is less effec- tive in terms of cost compared to an in-situ construction method. According to previous studies in Korea, in-plant production cost of PC members accounts for 75–77% of total cost of PC framework, transportation cost is 7–10% and erection cost is 15–17%. If qualitative in-situ production is possible, more than 10% of in-plant production cost and 7–10% of the transportation cost can be reduced, resulting in better cost competitiveness. Yet, in-situ produc- tion of PC members has complicated issues such as securing site traffic and resolving interference with other work. This study is intended to develop algorithms that can quickly establish a production layout plan by consid- ering in-situ production factors affecting composite precast concrete members. Usefulness of the developed algo- rithms has been demonstrated through a case study. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Generally, precast concrete construction, hereafter referred to as the “PC” method of construction, is preferred for industrialized building sys- tem construction due to its advantages, including fast erection, higher quality, lower project cost, better sustainability, and enhanced occupa- tional health and safety [1–5]. However, in Korea, since the PC method was introduced in the 1960s, it could not be sustainably developed due to issues related to difficulties in fabrication, quality defects and cost overruns [6,7]. Even though the PC method used for high-rise build- ings in downtown areas increases productivity, it generates other prob- lems such as traffic control on site, damages during movements and increased transportation cost. The quality of PC members is determined by the quality of form- works, vibrating and curing in the production process. If it is possible to perform such works in good quality on site, quality of PC members manufactured offsite or in plant is likely to be lower than that of PC members manufactured on site due to the damage during transporta- tion of PC members from the production area to the stockyard for curing and from the stockyard to the construction site for installation [8]. And the quality of buildings is determined by the stability of PC joints and the accuracy of installation. According to the survey of three main local PC manufacturers in Korea, the construction cost of building structures using in-plant pro- duced PC members comprises approximately 75–77% of the total cost for in-plant PC production, 7–10% for transportation and 15–17% for erection. The 10–15% or higher than that of in-plant production cost ac- counts for overhead and profit. If quality PC members can be produced in site without transportation or any movement for erection after production, the total cost can be reduced by 14.5–21.6% comprising 7–10% for transportation and 10–15% of overhead and profit deduction from in-plant production cost, equivalent to 7.5–11.6% of the total cost. Considering the facts described above, it is more reasonable to perform in-situ PC production within the working radius of tower cranes than in-plant production in terms of quality and cost. However, in-situ PC production is not always feasible in the limited area. Recently, as environmentally-friendly and cost-saving structures have become a main issue in housing construction projects in Korea, a column–beam system based on composite precast concrete (CPC) members, Green Frame (GF), that are superior for reducing CO 2 emis- sions and cost reduction was developed [9–12]. If CPC members of GF are manufactured by in-situ production, less production area is required compared to the conventional bearing wall PC method that needs wide area for panel PC production [13]. Unlike the in-plant production of PC members, in-situ production needs to secure the production area by taking into account access roads of workers and vehicles, temporary stockyard of finish materials and appropriate clearance area near the building for safety. And a Tower Crane (TC) or TCs should be arranged to directly lift and install Automation in Construction 41 (2014) 50–59 ⁎ Corresponding author. Tel.: +82 31 201 2922; fax: +82 31 203 0089. E-mail addresses: hongwk@khu.ac.kr (W.-K. Hong), m60dx@khu.ac.kr (G. Lee), khlsh@khu.ac.kr (S. Lee), kimskuk@khu.ac.kr (S. Kim). http://dx.doi.org/10.1016/j.autcon.2014.02.005 0926-5805/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Automation in Construction journal homepage: www.elsevier.com/locate/autcon