Significance of intermodal freight modal choice criteria: MCDM-based decision support models and SP-based modal shift policies

This paper reviews modal choice decisions associated with intermodal freight transportation through decision support models based on the Multi-Criteria Decision-making (MCDM) techniques and modal shift policy as�sessments based on the Stated Preferences (SP) experiments. The objectives were to determine the relevant decision criteria and their relative significance, to define methods in use, and to identify respective policies that boost intermodality. Google Scholar database and manual search using identified keywords were conducted and references of the relevant articles were double-checked. Consequently, a total of 27 articles consisting of respective 18 and 9 MCDM-based and SP-based articles were reviewed in this study. The results showed that the most commonly used decision criteria were cost, CO2 emissions, delivery time, safety, reliability, flexibility, and frequency. The cost factor was assigned the highest weight in 22 articles (or 81.4%). Analytical Hierarchy Process (AHP) technique was implemented in 12 out of 18 MCDM articles (or 66.6%)). Successful application of MCDM methods (both single and integrated) showed the suitability of these methods for intermodal freight modal choice decision-making. The results of SP experiments revealed that cost reduction policies are more effective than policies addressing other factors to increase the demand for intermodal transportation

A Review of Strategies to Prevent On-Site Construction Waste

One of the most important concerns that improves building profitability is the implementation of a positive approach to minimize construction waste. This paper will discuss the roots of construction waste, current waste reduction strategies, and lastly the possible use of waste management. Furthermore, the key environmental priority for this issue should be to control and mitigate construction waste generation. The purpose of this study is to provide prevention measures, and the rising tide of public awareness is all conspiring to modify the face of waste management. Clients, contractors, suppliers, and designers Architects & Engineers all have opportunities and duties to reduce construction waste. The outcomes of this study will assist academics in furthering their research into important management strategies for reducing on-site building waste

Economic and environmental life cycle assessment of alternative mass timber walls to evaluate circular economy in building: MCDM method

The construction industry is one of the largest consumers of energy and materials, which leads to it being one of the highest sources of environmental emissions. Quantifying the impact of building materials is critical if strategies for mitigating environmental deterioration are to be developed. The lifecycle assessment (LCA) consequential methodology has been applied to evaluate diferent methods of constructing residential double-story buildings. The ReCiPe methodology has been used for life cycle inventory. Three diferent forms of mass timber construction have been considered including cross-laminated timber (CLT), nail-laminated timber (NLT), and dowel-laminated timber (DLT). These have been assessed as load-bearing panels or wood frame construction. We evaluated the global warming potential (GWP), embodied energy, and cost to identify the building type with the lowest impacts. The results revealed that total CO2 emissions for mass timbers for the construction stage are 130 CO2/M2 , 118 CO2/M2 , and 132 CO2/M2 of the panel for CLT, DLT, and NLT, respectively. The embodied energy emission is 1921 MJ/M2 , 1902 MJ/ M2 , and 2130 MJ/M2 related to the CLT, DLT, and NLT, respectively, for this stage. The results also indicated that the carbon emission of DLT is lowest compared to the other two alternatives in the manufacturing and construction stages. However, when the entire life cycle is considered, NLT is the most favorable material. However, based on the life cycle cost (LCC), DLT has a lower cost. Finally, multiple-criteria decision-making (MCDM) was used to normalize the results and compare the alternatives. This showed DLT to be the best alternative, followed by CLT and NLT. In conclusion, the selection of building materials needs to prioritize regulations to reduce environmental and economic impacts

Life cycle assessment of brick and timber house and effects on climate change in Malaysia

Environment education is an important issue not only from the origination stage but also from the value of sustain it for now and for next generations. From the 1990s, the importance of environment conserve becomes understood for conservation effort in many areas. Among all activity, building construction industry played the principal roles in improving the environment, therefore attempt to mitigate effects from building constructions to environment. Sustainable development needs a method to evaluate and compare the environmental effect of human activity on any economic for various products. Environmental impacts include emission into the environment and utilization of resources as well as other inventions such as land use to build new products. The materials consist of brick and timber house with different roof materials. This study review the extraction of raw materials until the erected of building on the site. The objectives show that how much this construction can effect on climate change and human toxicity by building construction. The aim of this article is introducing the most friendly environment material for building construction and result shows wood building is the preferable solution

Combinations of building construction material for residential building for the global warming mitigation for Malaysia

Global warming mitigation is used as a key to devise built environment strategies and sustainable policies in developed countries that aim to reduce the rate of carbon emissions. The goal of this research is to mitigate global warming from building construction by suggesting an alternative building scheme for Malaysia. A problem related to the building industry is releasing carbon dioxide emission. Use of timber for construction has less impact on the environment due to less carbon dioxide emissions, thus making wood the best material for wall construction. However, as the Malaysian climate is hot and humid, wood encounters many defects and deteriorates. Presently, most buildings in Malaysia are built from other materials such as concrete or brick. In the last 40 years, wood materials in building schemes in Malaysia have dropped from 60% to almost 5%. This research proposed a new approach to minimize the effect of CO2 emission for buildings as well as to improve their structural stability for a longer lifespan because these would encourage the Malaysian construction industry to use wood components in their building schemes. In this study, SIMAPRO Software was used to assess CO2 emissions caused by seven different types of building schemes in wall constructions. The results from a simulation of three time frames of twenty, one hundred and five hundred years showed that timber scheme is the best choice for construction. To promote the use of timber, a new building scheme that would solve the problem of timber wood structure in Malaysia were proposed. The alternative building scheme has combined precast concrete and timber (H8) to improve the timber scheme deficiency while releasing less CO2 emissions compared to other systems. Therefore (H8) could replace current building schemes. This research can facilitate decision-maker to choose the most flexible scheme for Malaysian housing. Thus, this system could be positively and widely used in the Malaysian construction industry

"New residential construction building and composite post and beam structure toward global warming mitigation"

The construction industry has become one of the major sources of global greenhouse gas (GHG) emissions. Therefore, low carbon buildings have been assigned for reduction of human impact on the environment. The aim of this research is to decrease the CO2 effect from the building sector by eventually proposing a new structure for Malaysian construction with regard to the needs of this industry. Life cycle assessment (LCA) has been performed to analyze the CO2 emission for the Malaysian residential single family house. Seven different materials or structures have been assessed and the result shows that timber prefabricated post and beam is the best choice due to releasing less CO2 emissions to the atmosphere. However, timber has become almost forgotten as building material for house builders in Malaysia in the last four decades. The alternative building scheme has been made by reinforced steel plate into wooden beam and column and timber wall (S8) to improve the building structure deficiency and load bearing while releasing less CO2 emissions in comparison to other buildings. New structure has been designed by steel plate sandwiched between wood members and held together with bolts in beam and post toward decreasing the percentage of improper design and to improve accuracy in the execution of timber structure. Thus, new scheme (S8) could be advised to house maker and government as a new policy to promote the sustainability in construction sector

A comparative life cycle assessment (LCA) of concrete and steel-prefabricated prefinished volumetric construction structures in Malaysia

In recent years, off-site volumetric construction has been promoted as a viable strategy for improving the sustainability of the construction industry. Most prefabricated prefinished volumetric construction (PPVC) structures are composed of either steel or concrete; thus, it is imperative to carry out life cycle assessments (LCAs) for both types of structures. PPVC is a method by which free-standing volumetric modules—complete with finishes for walls, floors, and ceilings—are prefabricated and then transferred and erected on-site. Although many studies have examined these structures, few have combined economic and environmental life cycle analyses, particularly for prefinished volumetric construction buildings. The purpose of this study is to utilize LCA and life cycle cost (LCC) methods to compare the environmental impacts and costs of steel and concrete PPVCs “from cradle to grave.” The results show that steel necessitates higher electricity usage than concrete in all environmental categories, while concrete has a higher emission rate. Steel outperforms concrete by approximately 37% in non-renewable energy measures, 38% in respiratory inorganics, 43% in land occupation, and 40% in mineral extraction. Concrete, on the other hand, performs 54% better on average in terms of measures adopted for greenhouse gas (GHG) emissions. Steel incurs a higher cost in the construction stage but is ultimately the more economical choice, costing 4% less than concrete PPVC owing to the recovery, recycling, and reuse of materials. In general, steel PPVC exhibits better performance, both in terms of cost and environmental factors (excluding GHG emissions). This study endeavors to improve the implementation and general understanding of PPVC

Economic and environmental life cycle perspectives on two engineered wood products: comparison of LVL and GLT construction materials

The embodied carbon of building materials and the energy consumed during construction have a signifcant impact on the environmental credentials of buildings. The structural systems of a building present opportunities to reduce environmental emissions and energy. In this regard, mass timber materials have considerable potential as sustainable materials over other alternatives such as steel and concrete. The aim of this investigation was to compare the environment impact, energy consumption, and life cycle cost (LCC) of diferent wood-based materials in identical single-story residential buildings. The materials compared are laminated veneer lumber (LVL) and glued laminated timber (GLT). GLT has less global warming potential (GWP), ozone layer depletion (OLD), and land use (LU), respectively, by 29%, 37%, and 35% than LVL. Conversely, LVL generally has lower terrestrial acidifcation potential (TAP), human toxicity potential (HTP), and fossil depletion potential (FDP), respectively, by 30%, 17%, and 27%. The comparative outcomes revealed that using LVL reduces embodied energy by 41%. To identify which of these materials is the best alternative, various environmental categories, embodied energy, and cost criteria require further analysis. Therefore, the multi-criteria decision-making (MCDM) method has been applied to enable robust decision-making. The outcome showed that LVL manufacturing using softwood presents the most sustainable choice. These research fndings contribute to the body of knowledge about the use of mass timber in constructio