3D-Printed Carbon Absorbing High-Performance Building Structure
Booth 1014 at ARPA-E Summit 2022
Authors
Masoud Akbarzadeh (PI), Architecture, University of Pennsylvania
Dorit Aviv (co-PI), Architecture, University of Pennsylvania
Peter Psarras (co-PI), Architecture, University of Pennsylvania
Shu Yang (co-PI), Materials Science and Engineering, University of Pennsylvania
Mohammad Bolhassani (co-PI), Architecture, The City College of New York
Zheng O’Neil (co-PI), Mechanical Engineering, Texas A&M University
Billie Faircloth (co-PI), KieranTimberlake
Hua Chai, Teng Teng, Yefan Zhi, Yi Yang, Xiang Zhang, Zherui Wang, Kunhao Yu, Sohee Nah (University of Pennsylvania), Youngsik Choi (Texas A&M University), Ryan Welch (KieranTimberlake)
Project Date
2022-
Acknowledgements
This research is funded by the Advanced Research Projects Agency – Energy (ARPA-E) of U.S. Department of Energy (DE-FOA-0002625 2625-1538).
Technology Summary
An innovative design strategy for a carbon negative
building system.
- A high-performance, prefabricated, funicular floor structure with minimized mass and maximized surface area for carbon absorption.
- A novel carbon absorbing concrete mixture.
- Concrete 3D printing technology with post-tensioned prefabricated parts to reduce construction waste and enhance structural performance.
- Using additional bio-based carbon storing materials in secondary structural systems.
- Exploiting thermal mass, adaptive envelope, and electrified building systems with heat pumps to reduce operational energy over the building’s life cycle.
- A Building Information Modeling (BIM)-integrated life cycle analysis (LCA) feedback loop.
- The combined strategies ensure carbon negativity on a cradle-to-gate and cradle-to-grave basis.
3D Printed Prefabrication
Minimized construction materials and maximized surface area.
- A high-performance, prefabricated structure with minimized mass and maximized surface area.
- Utilizing 3D-printed concrete technology and pre-stressed prefabricated components to diminish construction waste.
- Employing polyhedral graphic statics techniques to create a spaceframe-like shape that corresponds with a related force diagram.
- The angles and dimensions of the tension elements in the lower chord are fine-tuned to evenly distribute force, allowing for the integration of a continuous tensile component into the system.
- Our rapid and clear local optimization process enhances completed designs by transforming them into self-supporting geometries, rather than constraining them from the outset.
- By examining the geometry via a systematic sequence of toolpaths, it accommodates the predetermined printing resolution while maintaining the shell structure’s consistent thickness and curvature continuity.
Efficient Structural System
Minimized construction materials and maximized surface area.
- Compared with conventional beam elements, our innovative system shows elastic behavior while all the beams experience plastic deformation.
- The resulting printed elements are strong enough to resist the applied loads with minimum stress and deflection.
Carbon Absorbing Concrete Mixture
Efficient, printable, and durable carbon capture material.
- Incorporating CO2-absorbing materials in the concrete mixture to increase surface areas and bicarbonate uptake.
- The optimized concrete ink achieved performance characteristics, including mechanical strength, surface area, CO2 storage, printability, and buildability.
- Achieved compressive strength up to 46 MPa.
- Average specific surface area: 15 m2/g.
- CO2 storage up to 0.16 kg CO2/kg concrete.
- Possess excellent shear-thinning properties and buildability for 3D printing.
Operational Energy Reduction
Bridges active and passive design approaches.
- Acting as an excellent thermal capacitor, the lightweight 3d-printed concrete floor design stores heat and provides inertia against extreme temperature fluctuations. This in turn reduces building operational energy consumption and improves occupant thermal comfort.
- With expanded concrete surface area exposure, heat transfer rate and thermal storage potential increase while the material volume remains unchanged.
- On an annual basis, by adding thermal mass with expanded surface area exposure, our preliminary analysis achieves 812 additional comfort hours in the core zone alone during the occupied hours of a medium office building in a hot-dry climate.
- Heat pump systems provide heating and cooling via radiant hydronic systems embedded in the building thermal mass.
- Heat pump systems operate with low-exergy heat sources and renewable energy sources.
Lifecycle Assessment
Iterative modeling of pathway to net zero GHG emissions.
- The Proposed System is expected to reduce building weight, provide passive and active thermal exchange, and afford space for system routing.
- These features could offer savings in several forms: reduced foundations, reduced mechanical equipment, energy savings, and lower floor-to-floor height, which in turn would yield savings in envelope materials and finishes.
- Carbonation is an essential performance attribute of the proposed system, so direct lab measurements of CO₂-uptake rates for alternative mix designs under various environmental conditions will be necessary to develop estimates of how elementary CO₂ flows respond to mix-design, mass, exposed surface area, environmental conditions, and end-of-life scenario.
Vision: Integrated Carbon Negativity
Capture full co-benefits of novel systems.
- Reduction in concrete volume and improvements in mix design will yield an 85% reduction in A1-A3 GWP for building superstructure, relative to best-in-class incumbent reinforced concrete construction practice.
- Use of off-site-printed modular structural system will substantially reduce emissions from transportation and reducing erection time to site (A4) and on-site construction (A5) through lower weight and elimination of formwork.
- Integration of mechanical systems within structure will eliminate need for mechanical plenums, leading to material savings in ductwork and finish materials, as well as reducing floor-to-floor height.
- Lower floor-to-floor-height will lead to material savings in vertical envelope, partitions, and building cores, as well as energy savings from envelope gains and losses.
- Reduced building weight will lead to material savings in foundations.
- Incorporation of bio-based and carbon negative building materials for interior and building envelope assemblies will be curated to offset remaining emissions.
