Guidelines for Rebar Cutting Lists to Minimize Rebar Scraps by Genetic Algorithm

Abstract

The purpose of this research is to be a guideline for rebar cutting list to obtain the least amount of rebar and rebar scrap using Genetic Algorithm. The research started by taking the 2D model of a 4-storey earthquake-resistant reinforced concrete building to create a 3D model with the level of development LOD300 and LOD350 models by using software BIM. Then set a pattern of lapped splice of columns. According to the standards of reinforced concrete structures to resist earthquakes (DPT.1301/1302-61) with 3 patterns of lapped splice of columns, namely, Pattern 1 (C1-1) lapped splice with a rebar in the middle of the 2nd floor, pattern 2 (C1-2) lapped splice with a rebar in the middle of the 3rd floor, and pattern 3 (C1-3) lapped splice with a rebar in the middle of every floor. The results of the processing of the BIM software are displayed in the form of a rebar cutting list containing rebar length data and the amount of rebar needed. The researcher then designed a Single Objective Function and determine relevant parameters for the rebar cutting list by using a genetic algorithm method to calculate the suitability of the use of rebar and rebar scrap. The research has compared the rebar from rebar cutting list of experienced engineers and of genetic algorithm models. The study found that the genetic algorithm models rebar cutting list of the C1-2 columns use rebar at a length of 12 meters resulted in the least amount of rebar being used, which was 33,557.16 kilograms, with 1,781.78 kilograms of scrap remaining, representing the scrap ratio per amount of use equal to 5.31. This shows that the use of genetic algorithm methods is another option that produces good results close to the objectives of the construction organization.