Special-Length-Priority Algorithm to Minimize Reinforcing Bar-Cutting Waste for Sustainable Construction

Abstract

Reinforcing bars (rebar), which have the most embodied carbon dioxide (CO2) per unit weight in built environments, generate a significant amount of cutting waste during the construction phase. Excessive cutting waste not only increases the construction cost but also contributes to a significant amount of CO2 emissions. The objective of this paper is to propose a special-length-priority cutting waste minimization (CWM) algorithm for rebar, for sustainable construction. In the proposed algorithms, the minimization method by special and stock lengths was applied. The minimization by special length was performed first, and then the combination by stock length was performed for the remaining rebar. As a result of verifying the proposed algorithms through a case application, it was confirmed that the quantity of rebar was reduced by 6.04% compared with the actual quantity used. In the case building, a CO2 emissions reduction of 406.6 ton-CO2 and a cost savings of USD 119,306 were confirmed. When the results of this paper are applied in practice, they will be used as a tool for sustainable construction management as well as for construction cost reduction.

Quantitative sustainability assessment of remanufacturing waste reinforcing steel

“…This is based on typical concrete containing 25% cement (Basuhi et al., 2021; Total Concrete, Limited, 2023), and a specific volume of concrete of 0.42 m 3 /ton (Concrete Calculator, 2022). The amount of new rebar consumed ( N rebar , million tons) was calculated as N rebar = 0.077 C o , which is based on a mean of 0.077 ton of rebar in one cubic meter of concrete (Kwon et al., 2021; Lee et al., 2020). The quantity of new rebar generated (million ton) was calculated based on a lower bound of RW low = 0.03 N rebar and upper bound of RW high = 0.1 N rebar , assuming 3%−10% rebar waste (Lee et al., 2020).…”

Fluxo de trabalho automatizado para otimização multiobjetivo de vigas de concreto armado

“…Khondoker (2021) também abordou o uso da metodologia BIM e uma formulação matemática do PCE para minimizar o consumo de barras de aço, em pórticos planos, no entanto, utilizando técnicas de programação linear inteira mista. Lee et al (2020) propuseram um algoritmo para minimização do desperdício por corte obtendo reduções de 6% do aço empregado e reduzindo as emissões de CO2 em 3,93%. Nadoushani et al (2018) aproveitaram flexibilizações de normas de elaboração de projeto de estruturas de concreto armado, sobretudo no que tange ao posicionamento das emendas de barras de aço, para variar sutilmente o detalhamento de armação de aço.…”

Reinforcement Concrete Steel Bar Trim Loss Optimization Using Metaheuristics Particle Swarm Optimization and Symbiosis Organisms Search

“…Menurut Global ABC (2019), industri konstruksi pada tahun 2018 berkontribusi atas 36% dari pemakaian energi dan emisi karbondioksida (CO2) sebesar 39% di bumi. Dari total keseluruhan pemakaian energi dan emisi rumah kaca untuk struktur beton sebesar 65%, baja tulangan beton memiliki andil sebesar 25% (Lee et al, 2020).…”