Life Cycle Assessment and Life Cycle Cost for Composite Bridges - Stainless Steel Corrugated Web Girders vs. Carbon Steel Flat Web Girders
Typ
Examensarbete för masterexamen
Program
Publicerad
2022
Författare
Nissan, Ashur
Woldeyohannes, Yohannes
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Bridge constructions account for numerous material and energy consumptions. Hence,
it is crucial to evaluate bridges’ environmental impact and total life cycle cost in
the early design stages. Data assumptions are made throughout the inventory stage
due to the lack of significant required data; therefore, the sensitivity of the LCA and
LCC outcomes should be considered. Steel is strongly used in bridge constructions
due to its high strength and efficient recycling rates. However, steel has low resis tance against corrosion which requires applying additional coating layers throughout
its life cycle and returns in additional expenses. Accordingly, the bridge industry
has been increasingly interested in providing more sustainable solutions. Stainless
steel has been widely used in bridge designs thanks to its high corrosion resistance.
Therefore, stainless steel bridges do not require regular maintenance activities. Nev ertheless, stainless steel has high material initial costs. Thus bridge designers have
developed different bridge design concepts to lower the total weight of stainless
steel required in bridges made of this material. One of these design concepts is the
application of corrugated webs in stainless steel bridges. In this master’s thesis,
a parametric model in Python has been developed to evaluate the environmental
impact of global warming potential and the total life cycle cost of different bridge
design concepts. In particular, two design concepts have been introduced and com pared, carbon steel S355 with flat web and Duplex stainless steel with corrugated
webs. The results showed that the stainless steel design concept has a lower total
environmental impact contributing to the global warming potential. Considering
the total life cycle cost, the results indicated that the economic feasibility of using
stainless steel with corrugated webs is highly dependent on the fluctuating prices of
stainless steel. Additionally, the outcome stated that when the average daily traffic
was relatively high, the stainless steel design concept became more economically
feasible than the carbon steel design concept. This study concluded the following
parameters as critical for LCC: the average daily traffic, the material initial costs,
the discount, and the escalation rate. The developed tool has been used in another
master thesis to optimize steel bridges based on LCA and LCC.
Beskrivning
Ämne/nyckelord
life cycle assessment, life cycle cost, optimization, corrugated webs, global warming potential, bridge industry, inital costs, average daily traffic.