The CTBUH has reached the next stage of a research project which aims to assess the environmental impacts and energy consumption of tall building structures, from the production of the building materials to their end-of-life.
The project is dubbed A Whole Life Cycle Assessment of the Sustainable Aspects of Structural Systems in Tall Buildings.
A total of 12 leading structural engineering firms have provided material quantities of 16 different structural scenarios, eight for a 248-metre tall tower, and eight for a 490-metre-tall tower which, if constructed, would be the fifth-tallest skyscraper in the world.
The research will be based on the Life-Cycle Assessment (LCA) analysis of a number of different structural and construction scenarios.
Structural scenarios include: all-concrete construction, composite columns, 100 per cent steel diagrid structures and mixed structures with concrete cores and steel columns.
The research will create a definitive comparison of the life-cycle implications of steel, concrete and composite structural systems in tall buildings.
The study will also develop a methodology for the assessment of life cycle energy and carbon use in tall building structural systems, which could be adopted as a standard tool for the industry.
“This study is timely and unique because it encompasses all processes and environmental releases, beginning with raw material extraction, design through construction, use and final demolition or re-use of the system,” said CTBUH senior research associate and co-principal investigator Dr. Payam Bahrami.
“When deciding between two or more alternatives, LCA can help decision-makers compare all major environmental impacts caused by systems, processes or services.”
Last year, the research team visited demolition company Despe to understand the complicated and still-unstudied aspects of the demolition of tall building structures and gather data on the energy consumption used in the demolition phase.
This data will be used to understand the impacts demolition has on the total life cycle energy consumption of a tall building, considered against the energy consumption of the construction and operational phases.
The team also discovered more about Despe’s patented “TopDownWay” method to demolish buildings. It involves these of a modular steel platform that caps the top of the building, enclosing the demolition activity, which occurs at the top floor.
This prevents dust and noise from escaping the building and allows operations to be conducted safely, potentially on a 24-hour basis.
When the top floor of the building is entirely demolished, the platform is jacked down one floor and the work continues, taking the building down in a method almost unnoticeable from the exterior.
Other visits made as part of the research process have included trips to the United States where meetings were held in Illinois with Bluff City Materials, which takes in clean, broken concrete for recycling before selling it to contractors. The purpose was to gain a greater understanding of the amount of energy that goes into recycling concrete, along with the volume of concrete recycled on a daily, monthly, and yearly basis.
The CTBUH is expected to report its final findings in November, 2014, with several further interim outputs to be issued before then.
The multi-faceted research project is sponsored by a $300,000 grant from ArcelorMittal.