Optimal Utilization of Rebar Stock for Cutting Processes in Housing Project

Abstract

Abstract:The cutting processes of rebar stock in housing project cause a large amount of waste because of high variety between required rebar lengths and standard rebar lengths, this problem is called one dimensional cutting stock problem. This research aims to utilize the rebar stock and minimize the losses using integer linear programming approach-aided by Advanced Interactive Mathematical Modeling System (AIMMS) software for solving the problems. These one-dimensional cutting rebar stock problems are divided into 19-problem according to the variety in the rebar diameter (25 mm, 16 mm, 12 mm, and 10 mm), and the variety in the design of activities in that housing project. The losses that are produced for each activity are utilized in the next activity when the length of item losses is larger than the required small item lengths in next activity for the same rebar diameters. That makes the utilization is to be maximized, where the Utilization Stock Ratio is reached to (98.53%).

Cutting Waste Minimization of Rebar for Sustainable Structural Work: A Systematic Literature Review

“…Therefore, it is confirmed that there are not many articles directly dealing with this topic. As shown in Table 5, 37 articles were published in the journal [3,4,6,[8][9][10][11][12]63, and 11 articles were published in peer reviewed conference publication [7,55,62,71,[111][112][113][114][115][116][117]. The rest have three dissertations [5,118,119] and one book chapter [120].…”

“…Adjusting lap splice position to satisfy structural code to make the length of rebars used for cutting patterns constant [6,7,12,86,105,108,112,119] StL Performing CWM on rebar in stock or market length [3,4,6,[9][10][11]86,90,104,105] SpL Performing CWM on rebars with special ordered length [3,4,6,10,90] As shown in Table 10, 10 rebar CWM-related articles are described for rebars of stock length (StL) or market length. This is because the CSP study on the optimization of the material of one-dimensional stock length stored in the factory is the beginning of rebar CWM.…”

“…Over the past few decades, numerous studies have been conducted on minimizing cutting wastes, and various optimization algorithms have been proposed. However, in reality, cutting wastes are still generated in the process of cutting and bending of rebars, which are at least 3% to 5% [3][4][5][6][7], and as much as 5% [4,[6][7][8][9][10][11] to 8% [12], compared to the volume shown in the structural drawings.…”

“…In the case of LP, it has an advantage in terms of flexibility to be paired up with other approximations to improve convergence, but there is a disadvantage in terms of being slower in finding special-length-priority or waste-rate-priority solutions under multiple search conditions. In studies of rebar's CWM, 12 articles were selected as optimization techniques [3][4][5]7,9,12,63,86,93,96,109,114]. The reason for this is that CSP or CWM problems have been adopted most often in modeling and have become more common.…”

Near-Zero Rebar Cutting Waste Management by Adjusting Lap Splice Position

“…Rebar cutting waste (RCW) is generally estimated to be 3-5% in the construction planning stage [1][2][3][4]. However, technology to reduce RCW was not developed at the construction field, so more than 5% is generated in the actual construction [5][6][7][8][9]. To solve this problem, many studies was conducted to minimize RCW [10][11][12][13][14].…”