Trudeau, J. and Sands, D. AIA, MA and and Nguyen, Quy.
Owners of Bamboo Technologies and Bamboo Hardwoods.
120 Hana Highway #9, Suite 133, Paia, Hawaii 96779 USA
ABSTRACT:
This paper presents the work of Bamboo Technologies and Bamboo Hardwoods toward the development of an accepted building code for habitable bamboo structures in the Western World. Six different prefabricated bamboo structures have been designed, erected, and permitted as non-dwelling structures in Hawaii, USA. The houses are manufactured in Vietnam using Vietnamese bamboo, Bambusa stenostachya. This species is currently being tested by ICBO certified labs. The results of the tests and subsequent reports will allow the construction of these houses to be permitted as dwelling structures any where in the Western World.
KEYWORDS: bamboo, bamboo housing, bamboo structures, construction, ICBO, evaluation report, Bambusa stenostachya, building code, building permit, prefabricated.
1. INTRODUCTION:
At Bamboo Hardwoods (BH) of Seattle in collaboration with Bamboo Technologies our objective over the past seven years has been to develop methods of construction using bamboo that can gain building code acceptance and can be built affordably and to build structures using those methods. This paper will describe the methods we have developed and the projects we have done using those methods. Further we will explain where we are in the process of making code acceptance easier and construction less expensive.
In many parts of the world bamboo has long been used as a structural building material. The perceived worldwide timber shortage, coupled with the fast rotation period and excellent strength properties make bamboo a sensible alternative construction material. Currently, however, bamboo is not popular in the United States as a structural material. When bamboo houses can be permitted as dwelling structures the popularity and demand for bamboo houses and bamboo construction materials will dramatically increase in the USA and the Western World.
We have developed six different prototype prefabricated kit homes which have been built in the state of Hawaii. These kit homes are manufactured in Vietnam using Bambusa stenostachya. The houses are being shipped to locations around the world. A number of these homes have been issued building permits including the first building permit issued for a habitable bamboo structure in the USA. We are currently designing and building an interchangeable panel systems that can be used by architects and engineers throughout the world.
2. METHODS.
The building codes in the USA were designed to deal with the issues of insects, fire and wind as well as many other issues dealing with public health and safety. Design requirements to allow structures to sustain high winds, to resist deterioration from insects and moisture, and to slow or stop the spread of fire are laid out in the codes. The codes formalized the methods of construction allowed based on testing of materials and building systems to assure compliance with the design requirements.
The International Conference of Building Officials (ICBO) is one of the primary code writing organizations in the USA. It is responsible for developing criteria for the acceptance of building materials. Over the past several years, worldwide bamboo interests worked in conjunction with the ICBO to create the Evaluation Service Acceptance Criteria for bamboo(Acceptance Criteria for Structural Bamboo, AC162). The acceptance criteria defines the process to achieve building code approval.
We are currently in the middle of working through this process to achieve building code approval for our bamboo structures using Bambusa Stenostachya. We are contracted with internationally accredited testing laboratories that are testing culms of bamboo. In one of the final steps in the process, the ICBO will issue an Evaluation Services Report. This report will be a synopsis of how the bamboo met the acceptance criteria.
The major tasks required to achieve building code approval for this new housing system, include:
1. Material Sampling.
2. Property Characterization.
3: Quality Assurance Manual.
4: Code Submission.
To establish adequate performance criteria the material properties for bamboo elements must be quantified. The bamboo test specimens (3-in. nominal diameter, 8-ft. length) were harvested and shipped to Washington State University for evaluation. Samples of Bambusa Stenostachya were randomly selected from the regions where BH has bamboo plantations. All sampling was witnessed by a third party inspection agency. PFS Corporation provided inspection services. A comprehensive set of tests will be conducted at the Wood Materials and Engineering Laboratory in Pullman, Washington, USA, to establish the mechanical properties of bamboo according to the ICBO AC162 Acceptance Criteria. Bamboo samples will be sorted and grouped by nominal diameter and species. One hundred and ten replicates will be tested in each group according to the guidelines of AC162. The test data can be used to establish the following design values for this one species of structural bamboo:
# Bending modulus of elasticity (MOE)
# Bending strength
# Tensile strength parallel to grain*Compressive strength parallel to grain
# Shrinkage of diameter and length
# Shear strength parallel to grain
# Nail withdrawal resistance perpendicular to the face of the culm
# Specific gravity
These data will be analyzed and categorized into grades according to their structural properties. Depending on product performance, quality assurance limits will be specified to cull from the population material not suitable for structural purposes. The data will be summarized into a report suitable for submission to the ICBO Evaluation Service. Connection testing will be conducted in subsequent projects. A final report describing the testing and analysis will be provided to the International Standard Organization (ISO). The testing/analysis report and the code submission package will be provided to Bamboo Hardwoods at the end of the project, whereupon BH can make the submission to various code organizations.
As a result of the completion of this testing and Evaluation Services Report bamboo will become an internationally recognized code approved building material. (ICBO is an international organization itself and their work is accepted by other code writing organizations.) This program will generate a quality assurance system resulting in structurally graded bamboo that will become a model for structural use of bamboo around the world.
The following is an overview of our work developing structural bamboo housing over the past seven years:
1995, September. Constructed first field test prototype of bamboo house. Included bamboo trusses and bamboo wall framing. Walls and ceiling were overlaid with Ferro cement.
1996, September. Received final approval granted for first test prototype by Maui County Building Department, USA, for the first building to be permitted under Western Building Codes.
1997, July. Sponsored Dr. Jules Janssen, expert in the field of bamboo testing at the University of Eindhoven in the Netherlands, to make presentations to building departments on all four islands in Hawaii. Also, sponsored the first International Conference on Bamboo on the Big Island of Hawaii.
1997, October. Established professional partnership with Linda Garland, International Bamboo Foundation.
1998, September. Conducted extensive lab test at University of Washington (UW) to determine the structural properties of construction grade bamboo (Dendrocalamus Strictus).
1998, October. Hired engineering firm to do the first structural analysis using data from UW.
1998, December. Made initial contacts with International Conference of Building Officials (ICBO). Began setting up guidelines for testing bamboo with in the international construction model.
1999, April. Established final documentation necessary before internationally accepted testing data can be used (Evaluations Acceptance Criteria Report) with Jules Janssen, ICBO, and International Standards Organization (ISO).
2001, February. Met in Seattle with 3 prospective labs and consultants to begin testing analysis in Vietnam.
2001, March. Created testing team: Kurt Stochlia, vice president of ICBO. Dr. Jules Janssen, bamboo research expert. Bob Nelson of PFS Corporation, testing labs. Dr. Deepak Shresthra, of Washington State University, Testing Labs. Robert Tichy, consultant for development of quality control manuals.
2001, May. Translated first quality control documents into Vietnamese for the factory.
2001, June. Kai Hawaii Inc., Structural Engineering firm on Oahu established critical design criteria for 4 bamboo structures to be submitted for permits.
2001, September. University of Hawaii began tests on culms from Vietnam. PFS Corporation began testing process for ICBO certification.
2001, October. One hundred and eighty bamboo culms were collected under the witnessing program of PFS Corporation to be used for testing at Washington State University. Quality assurance program witnessed and refined both in field and factory in Vietnam.
2001, November. Testing samples sent to Washington State University.
2001, December. Testing began at Washington State University and data was
compiled in conjunction with University of Hawaii.
3. CONCLUSION:
Bamboo Hardwoods and Bamboo Technologies are pioneering the way to bring construction grade bamboo and bamboo houses to meet building code standards in the western world. Additionally, there will be a protocol for quality control of bamboo and the first internationally accepted grading system for bamboo. Once these prefabricated houses are permitted as habitable structures, the use of bamboo for construction purposes should increase dramatically. Technicians at Bamboo Technologies are available for consultation in assisting other companies to bring any other species of bamboo through the building code process. Bamboo Technologies is currently developing a comprehensive web site for the architectural and engineering aspects of building with bamboo. The web site will be linked to the largest body of resource information available on the technical data for the structural use of bamboo products.
Bamboo Research Powerpoint Presentation