LIFE CYCLE ENERGY AND ENVIRONMENTAL IMPACTS OF CROSS LAMINATED TIMBER MADE WITH COASTAL DOUGLAS-FIR

In this study,a cradle-to-gate life-cycle assessment(LCA)of Oregon-made cross-laminated timber(CLT)was conducted as per the ISO guidelines.Primary data pertaining to CLT manufacturing was collected from a production facility in Oregon and modeled with existing LCA data of Pacific Northwest softwood lumber production and harvesting operations.Primary energy is reported and encompasses all processes within the system boundary.Carbon emissions are reported and include fossil-based emissions from transportation and all production processes and carbon storage in CLT.LCA results are presented for five impact categories,primary energy consumption,and net carbon impact of CLT.Results show the environmental advantage of CLT due to storing of large amounts of biogenic carbon in a building structure for a lifetime.The amount of carbon stored in CLT offsets the emissions released from all production processes;this indicates that CLT is a net negative carbon emitter,as more carbon is stored in the product than is emitted to produce the product.This study shows the importance of using the LCA methodology for showing the net amount and type of energy used for production and the potential climatic impacts of using wood products.This LCA study makes no comparative assertions.

COMPARATIVE CARBON FOOTPRINT ANALYSIS OF BAMBOO AND STEEL SCAFFOLDING

Building construction and maintenance is one of the major contributors to global warming and as a result has the potential to be a leader in sustainable develop-ment.Scaffolding systems are an important component of building construction,especially high-rise buildings.A scaffold consists of a modular system of metal or bamboo tubes or pipes.Scaffolding is a temporary construction structure created for reaching heights above a human’s reach,with the purpose of helping in con-struction or maintenance of a structure.The scaffolding industry in the US is dominated by steel.In areas where bamboo is indigenous,like many East Asian cities,bamboo is the scaffolding material of choice,even when it comes to high-rise buildings.Our goal was to analyze bamboo and steel thoroughly and estab-lish their environmental impacts using life cycle analysis(LCA).Consequently,this study explores the ecological viability in expanding the use of bamboo scaffolding where steel predominates.The functional units used in this study are bamboo and steel scaffolding systems that are 2.74 m high,2.49 m wide,and 1.21 m deep.A cradle-to-gate LCA was performed to evaluate the environmental performance of the two scaffolding systems.Our results suggest that bamboo scaffolding has a lower carbon footprint than steel scaffolding,with an ability to sequester carbon during its growth phase being a significant contributing factor.This is an important advantage of bamboo over nonrenewable materials(steel).Additionally,bamboo functions as a buffer,delaying the release of CO_(2) after the use phase.The main challenge for any scaffolding system made from renewable materials in the western world is the demand for standardization.Therefore,an ideal future goal should be the design of standardized scaffolding systems using renewable materials that com-bines the durability and homogeneity of steel scaffolding with the sustainability and environmental performance of bamboo scaffolding.