Light transmission performance of translucent concrete building envelope

Abstract

Energy efficient building envelopes are essential for sustainable development in civil engineering and architecture. In this preliminary investigation, a structural building envelope that is load bearing is developed for daylight harvesting. A translucent concrete panel (TCP) design is constructed using optical fibers (OFs) to transmit light and common concrete mix design. A steel mesh is embedded in the TCP to increase its structural load bearing capacity. It has the potential to save energy and reduce carbon footprint by collecting, channeling and eventually scattering the sunlight. Constructability issues including mechanical and optical losses are analyzed and discussed. Numerical models of the single OF and the whole TCP are developed using ray tracing software and the light transmission mechanisms are analyzed. Nonimaging sunlight collectors, namely compound parabolic concentrator (CPC), together with the OFs represent an efficient system for harvesting and guiding the sunlight into the interior spaces. The light transmission of a model made out of a CPC and an OF is evaluated from an energy efficiency point of view.

Keywords:

• translucent concrete
• building envelope
• daylight
• light transmission
• compound parabolic concentrator

PUBLIC INTEREST STATEMENT

Energy efficient building envelopes are essential for sustainable development in civil engineering and architecture. A translucent concrete panel (TCP) is constructed using optical fibers (OFs) to transmit light and common concrete mix design. It has the potential to save energy and reduce carbon footprint by collecting, channeling and eventually scattering the sunlight. Constructability issues including mechanical and optical losses are analyzed and discussed. Numerical models of the single OF and the whole TCP are developed using ray tracing software and the light transmission mechanisms are analyzed. Compound parabolic concentrator (CPC) and the OFs represent an efficient system for harvesting and guiding the sunlight into the interior spaces. The light transmission of a model made out of a CPC and an OF is evaluated from an energy efficiency point of view. The results will help to develop energy efficient buildings.

Acknowledgements

The authors thank Mr. J. Hlavaty, Lambda Research Corporation for tireless assistance, Prof. Zhang Min-Hong, National University of Singapore, for kind assistance of manufacturing of the panels. The presented research is funded by the Republic of Singapore’s National Research Foundation through a grant to the Berkeley Education Alliance for Research in Singapore (BEARS) for Singapore-Berkeley Building Efficiency and Sustainability in the Tropics (SinBerBEST) Program. BEARS has been established by the University of California, Berkeley as a center for intellectual excellence in research and education in Singapore. This work was also supported by China National Science and Technology Major Project with grants # 2016YFE0105600, and China National Science Foundation with grants # 51578411, 51608381, 51578405, International Joint Research Laboratory of Earthquake Engineering (ILEE) through grant number ILEE-IJRP-P2-P3-2017.

Cover image

Source: Author.

Additional information

Funding

This work was supported by the National Science Foundation of China [51608381].

Notes on contributors

Baofeng Huang

Baofeng Huang is an associate professor of the College of Civil Engineering, Nanjing Tech University. He received his BSc degree (2003) from Jinan University, and his MS (2006) and PhD (2014) degrees from Tongji University. He studies seismic performance of the nonstructural systems, experimental approaches in structural engineering and energy‐efficient buildings.