scholarly journals Cradle-to-Site Carbon Emissions Assessment of Prefabricated Rebar Cages for High-Rise Buildings in China

2018 ◽  
Vol 11 (1) ◽  
pp. 42 ◽  
Author(s):  
Boya Jiang ◽  
Hongxian Li ◽  
Ling Dong ◽  
Yu Wang ◽  
Yiqi Tao
Keyword(s):  
Co2 Emissions ◽  
Carbon Emissions ◽  
Sustainable Construction ◽  
The Sustainable Development ◽  
Reinforcing Bar ◽  
High Rise ◽  
Construction Methods ◽  
Three Stages ◽  
Material Preparation

Construction industrialization is growing rapidly and has received significant attention worldwide in recent years. The industrialization of construction results in several benefits, including the promotion of sustainable construction and the development and application of prefabrication techniques. The Prefabricated Rebar Cage (PRC) is an emerging solution applied to high-rise buildings as a replacement of the In-situ Reinforcing Bar (ISRB) construction method. This paper investigates the cradle-to-site carbon emissions of PRC, and compares the results with those of conventional in-situ rebar construction methods for high-rise buildings. The cradle-to-site cycle is divided into three stages, namely, material preparation, transportation, and on-site construction. For the material preparation stage, it is found that CO2 emissions are increased by 3% when using PRC due to the operation of machinery during the prefabrication process. In the transportation stage, CO2 emissions are found to increase by 3.3 times for PRC, as there is more transportation required for PRCs than for conventional construction methods. During the on-site construction stage, the PRC method demonstrates its advantages by reducing CO2 emissions by 44.7%, which is attributed to decreased hoisting frequency and lower mechanical utilization for fewer joining activities. Overall, CO2 emissions can be reduced by 1.24% by adopting the PRC method for high-rise buildings, and it is therefore recommended to adopt PRCs for this purpose. This research studies carbon emissions of PRC and contributes to promoting the sustainable development of prefabricated building techniques.

scholarly journals Study on the Carbon Emissions in the Whole Construction Process of Prefabricated Floor Slab

2020 ◽  
Vol 10 (7) ◽  
pp. 2326
Author(s):  
Aisan Kong ◽  
Haibo Kang ◽  
Siyuan He ◽  
Na Li ◽  
Wei Wang
Keyword(s):  
Carbon Emissions ◽  
High Energy ◽  
Construction Process ◽  
Floor Slab ◽  
Construction Methods ◽  
Calculation Results ◽  
Three Stages ◽  
Traditional Construction ◽  
High Energy Consumption

The construction industry is characterized by high energy consumption and high carbon emissions. With growing concern about climate change, environmental protection is becoming increasingly important. In this paper, the whole construction process of prefabricated floor slab (PFS) is divided into three stages: production, transportation, and construction stages. Carbon emissions are calculated based on the life cycle assessment (LCA) method. A case study of PFS construction in Shaoxing city, China, was examined, and the calculation results were compared and evaluated with the traditional construction methods, which showed that in the production stage, carbon emissions increased due to mechanical operations during the prefabrication process. In the transportation stage, carbon emissions also increased due to the heavier prefabricated components during the transportation process. During the on-site construction stage, carbon emissions considerably decreased due to the lower hoisting frequency and less on-site pouring.

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

2020 ◽  
Vol 12 (15) ◽  
pp. 5950
Author(s):  
Dongho Lee ◽  
Seunghyun Son ◽  
Doyeong Kim ◽  
Sunkuk Kim
Keyword(s):  
Co2 Emissions ◽  
Cost Savings ◽  
Construction Cost ◽  
Sustainable Construction ◽  
Unit Weight ◽  
Emissions Reduction ◽  
Reinforcing Bars ◽  
Minimization Method ◽  
Reinforcing Bar ◽  
Carbon Dioxide Co2

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.

scholarly journals Construction and Retrofit Methods of Stone Masonry Structures in Cyprus

2016 ◽  
Vol 10 (1) ◽  
pp. 246-258 ◽  
Author(s):  
Petros Christou ◽  
Miltiades Elliotis
Keyword(s):  
Structural Damage ◽  
Construction Material ◽  
Stone Masonry ◽  
Masonry Structures ◽  
Construction Methods ◽  
Three Stages ◽  
Natural Stones ◽  
Traditional Structures ◽  
Selection Of

Natural stone is a durable construction material which has been used through centuries for various types of structures. These structures are exposed to corrosive and degradation factors such as climate change and pollution, natural ageing, earthquake actions, increasing urbanization and even human negligence, potentially exposing them to irreversible structural damage and loss. Considering the large number of traditional structures and the historic value of a great number of stone masonry structures, the necessity of maintenance, repair, retrofit and restoration of stone masonry structures is imposed. The process which leads to the preservation of such structures consists of three stages: 1) the in-situ and laboratory study of the degree of damage and of the factors which cause the natural damages on the materials of these buildings, 2) the detailed drawing of the layout and the elevations. This stage also includes the selection of the appropriate measures for the maintenance and retrofits according to the special characteristics of the structure and the design of the intervention method, and 3) the execution of all the intervention works. This paper presents a description of various types of natural stones found in Cyprus, the most commonly used construction methods as well as methods for the retrofit of stone masonry structures.

scholarly journals Life Cycle Carbon Emission Analyzing of Rural Residential Energy Efficiency Retrofit-A Case Study of Gansu province

2021 ◽  
Vol 329 ◽  
pp. 01063
Author(s):  
Qiangnian Li ◽  
Tongze Han ◽  
Changlin Niu ◽  
Ping Liu
Keyword(s):  
Energy Efficiency ◽  
Life Cycle ◽  
Carbon Emissions ◽  
Gansu Province ◽  
Sustainable Construction ◽  
Residential Energy ◽  
Energy Retrofit ◽  
Construction Methods ◽  
Residential Energy Efficiency ◽  
Whole Life Cycle

Objective To study and analyze the life-cycle carbon emissions of existing rural residential energy retrofit projects to provide theoretical and data support for local rural green development and sustainable construction. Methods Life cycle analysis (LCA) was used to analyze and compare the life cycle carbon emissions (LCE) of a rural residential envelope energy efficiency retrofitting project in central Gansu. Results It was found that rural dwellings have a very high potential for energy efficiency retrofitting, and the contribution of retrofitted homes to CO2 emissions reduction can reach more than 30% over the whole life cycle. Secondly, during the retrofitting process, neglected in previous studies, carbon emissions account for about a quarter of the LCE. It is concluded that introducing LCA into evaluating rural residential energy retrofit projects' energy-saving and emission reduction benefits is more scientific, reasonable, and necessary.

scholarly journals Economic Development, CO2 Emissions and Energy Use Nexus-Evidence from the Danube Region Countries

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3165
Author(s):  
Eva Litavcová ◽  
Jana Chovancová
Keyword(s):  
Economic Growth ◽  
Energy Consumption ◽  
Co2 Emissions ◽  
Carbon Emissions ◽  
Bounds Testing ◽  
Mutual Cooperation ◽  
Long Run ◽  
Short Run ◽  
Danube Region ◽  
The Impact

The aim of this study is to examine the empirical cointegration, long-run and short-run dynamics and causal relationships between carbon emissions, energy consumption and economic growth in 14 Danube region countries over the period of 1990–2019. The autoregressive distributed lag (ARDL) bounds testing methodology was applied for each of the examined variables as a dependent variable. Limited by the length of the time series, we excluded two countries from the analysis and obtained valid results for the others for 26 of 36 ARDL models. The ARDL bounds reliably confirmed long-run cointegration between carbon emissions, energy consumption and economic growth in Austria, Czechia, Slovakia, and Slovenia. Economic growth and energy consumption have a significant impact on carbon emissions in the long-run in all of these four countries; in the short-run, the impact of economic growth is significant in Austria. Likewise, when examining cointegration between energy consumption, carbon emissions, and economic growth in the short-run, a significant contribution of CO2 emissions on energy consumptions for seven countries was found as a result of nine valid models. The results contribute to the information base essential for making responsible and informed decisions by policymakers and other stakeholders in individual countries. Moreover, they can serve as a platform for mutual cooperation and cohesion among countries in this region.

Analysis of Technical Characteristics and Construction Focus of Long-Span Continuous Rigid Frame Bridge with High-Rise Piers

2014 ◽  
Vol 587-589 ◽  
pp. 1637-1641
Author(s):  
Yao Cui ◽  
We Nang Hou ◽  
Fei Ying Liu
Keyword(s):  
Deep Water ◽  
Water Reservoir ◽  
Bridge Pier ◽  
Reservoir Area ◽  
High Rise ◽  
Construction Methods ◽  
Long Span ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Rigid Frame Bridge

Under the condition of the deep water reservoir area, the choice of bridge pier and long span continuous rigid frame beam construction methods are quite various. And the analysis of destruction of bridge depends mostly on the beam and piers. The paper cares mostly about these two parts.

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