LCA and LCC of the world’s longest pier: a case study on nickel-containing stainless steel rebar

Abstract

Purpose Built in 1941, the Progreso Pier was the first concrete structure in the world built with nickel-containing stainless steel reinforcement. The Pier has been in service for over 70 years without any significant repair or maintenance activities. The aim of this study was to understand the environmental and economic implications of selecting nickel-containing stainless steel reinforcement using the Progreso Pier as the case study. Methods A combined environmental life cycle assessment (LCA) and life cycle costing (LCC) study was conducted. The analysis considered the potential environmental impacts and the net present cost of the stainless steel reinforced structure from cradle to grave and compared it to the same structure using conventional carbon steel. Results and discussion The results indicated that while using stainless steel reinforcement resulted in a marginally higher environmental impact after initial construction, this is offset by the increased service life and, hence, less frequent maintenance and reconstruction activities. Relative to the as-built stainless steel reinforcement design, the environmental impacts of the carbon steel reinforced design are between 69 and 79 % higher over the analysis period. Similar observations were made for the other investigated impact categories. The cost implications of using stainless steel reinforcement show economic benefits that are complementary to the environmental benefits. Similar to the LCA, the service life benefits outweigh the higher unit costs for stainless steel, assuming a discount rate of 0.01 % as the baseline scenario. The carbon steel reinforced design has a net present cost that is 44 % higher than the as-built stainless steel reinforcement design. The crossover point for the two designs occurs at year 50, which corresponds to the reconstruction activity. A sensitivity analysis shows that the results and conclusions are sensitive to the choice in discount rate: Rates 3 % and lower produce net present costs that are lower for the as-built design; rates 4 % and higher produce net present costs that are lower for the alternative design. Conclusions The study demonstrates how LCA and LCC are complementary tools that can be used in decision-making for sustainable construction. The Progreso Pier exemplifies the importance of considering the entire life cycle with service life and recycling as well as long-term life cycle impacts of infrastructure projects from an environmental and economic perspective.

Sustainability assessment of concrete bridge deck designs in coastal environments using neutrosophic criteria weights

“…On the contrary, the worst environmental performances are those of the baseline design and the option based on stainless steel reinforcement. Such result confirms the relevant environmental burdens associated with the use of stainless steel in concrete reported by Mistry, Koffler, & Wong (2016). up to 17% greater than those of a properly chosen preventive strategy.…”

Life Cycle Cost Assessment of Preventive Strategies Applied to Prestressed Concrete Bridges Exposed to Chlorides

“…It is observed that an excessive concrete cover (R45 and R50) leads to great initial costs as well, due to the associated increase in the reinforcing steel demand. On the other hand, those solutions where the reinforcement material is modified, namely by using galvanized or stainless steel reinforcements, result in almost the highest initial costs, due to the high costs of materials [48]. At last, it is observed that the most expensive solutions in terms of initial costs are those where the reference concrete is modified with polymers.…”

Cost and environmental analyses of reinforcement alternatives for a concrete bridge

“…The selected value is conservatively higher (67%) with respect to the value recommended by the White House Office of Management and Budget (OMB) in circular A-94 (revised November 2017) (White House Office of Management and Budget, 2017) for long-term federal investments (≥30 years). Typical commercial discount rate values for long-term investments range between 1% and 8% (Mistry et al, 2016). The present work considers a public works discount rate of 1%, based on a previous study Cadenazzi et al (2019a).…”