A. Shop Drawings and Details for Tests
B. Sound and Impact Test Results Summary
C. Test 1: Sound and Impact Transmission Test - CLT
D. Test 2: Sound and Impact Transmission Test - Concrete Topping
E. Test 3a: Sound and Impact Transmission Test - Marmoleum
F. Test 3b: Sound and Impact Transmission Test - Marmoleum
G. Test 4: Sound and Impact Transmission Test - Carpet
H. Test 5a: Sound and Impact Transmission Test - Luxury Vinyl Plank
I. Test 5b: Sound and Impact Transmission Test - Luxury Vinyl Plank
J. Test 6: Sound and Impact Transmission Test - Mechanical Roof
Comprehensive guide to engineered wood construction systems for both residential and commercial/industrial buildings. Includes information on plywood and oriented strand board (wood structural panels), glulam, I-joists, structural composite lumber, typical specifications and design recommendations for floor, wall and roof systems, diaphragms, shear walls, fire-rated systems and methods of finishing.
Project contact is Thomas Miller at Oregon State University
Summary
Understanding how roof and floor systems (commonly called diaphragms by engineers) that are built from Pacific Northwest-sourced cross-laminated timber (CLT) panels perform in earthquake prone areas is a critical area of research. These building components are key to transferring normal and extreme event forces into walls and down to the foundation. The tests performed in this project will provide data on commonly used approaches to connecting CLT panels within a floor or roof space and the performance of associated screw fasteners. Structural engineers will directly benefit through improved modeling tools. A broader benefit may be increased confidence in the construction of taller wood buildings in communities at greater risk for earthquakes.
To support the associated Sir Matthew Begbie Elementary School and Bayview Elementary School projects in pushing the boundaries forward for long-span floor and roof construction, this testing project aims to compare different connection approaches for composite connections between glulam and cross-laminated timber (CLT) – for vibration, stiffness, and strength. Working with the University of Northern British Columbia (UNBC), Fast + Epp aimed to complete a series of vibration and monotonic load tests on 30’ long full-scale double-T ribbed panels. The tests consisted of screws in withdrawal, screws in shear, and nominal screws clamping with glue. Both the strength and stiffness are of interest, including slip stiffness of each connection type. This physical testing was completed in January and February 2020, where the full composite strength of each system was reached. Initial data analysis has provided information for comparison with existing models for shear connection stiffness. Publications will follow in 2021.
Concealed spaces, such as those created by a dropped ceiling in a floor/ceiling assembly or by a stud wall assembly, have unique requirements in the International Building Code (IBC) to address the potential of fire spread in nonvisible areas of a building. Section 718 of the 2018 IBC includes prescriptive requirements for protection and/or compartmentalization of concealed spaces through the use of draft stopping, fire blocking, sprinklers and other means.
The two-way action of Cross Laminated Timber (CLT) is often ignored in the design of CLT due to its complexity. But in some cases, for example, large span timber floor/roof, the benefit of taking the two-way action into account may be considerable since it is often deflection controlled in the design. Furthermore CLT panels are typically limited to widths of less than 3 m. therefore, for practical applications, engaging CLT panels in two-way action as a plate in bending would require connecting two panels in the width/minor direction to take out-of-plane loading. To address this technically difficult situation, an innovative connection was developed to join the CLT panels in the minor direction to form a large continuous two-way plate. The two-way action of CLT was also quantified. Static bending test was conducted on CLT panels in the major and minor directions to measure the Modulus of Elasticity (MOE). This provided a benchmark for the following connection test, and data for the future development of computer modeling. The average apparent MOE was 9.09 GPa in the major direction and 2.37 GPa in the minor direction. Several connection techniques were considered and tested, including self-tapping wood screws, glued in steel rods, and steel connectors. One connecting system was found to be effective. For the panel configuration considered, the system was consisted of steel plates, self-tapping wood screws, and 45° screw washers. Two steel plates were placed on the tension side with sixteen screws, and one steel plates was placed on the compression side with four screws. When the screws were driven into the wood, the screws were tightly locked with the washers and steel plates, and at the same time, the wood members were pulled together by the screws. This eliminated any original gap within the connection. The connector was installed to join two CLT members in the minor direction. They were tested under bending with the same setup as above. The connected panels had an average apparent MOE of 2.37 GPa, and an average shear-free MOE of 2.44 GPa, both of which were higher than the counterpart in the full panels. The moment capacity of the connected panels was also high. The minimum moment capacity was 3.2 times the design value. Two large CLT panels were tested under concentrated loading with four corners simply supported. The deflection of nine locations within the panels was measured. This data will be used to validate the computer modeling for CLT two-way action.
In this study, European engineers were surveyed to learn about their current level of awareness of CLT, the major barriers to CLT adoption, and about the most pressing research needs to advance the use of CLT as a construction material. The study used a web-based survey with a convenience sample of 93 different kinds of timber and civil engineers and/or researchers, most of which belong to a European CLT research network. Results showed that participants thik that, in general, the level of awareness about CLT among developers, construction managers, engineers, architects, and construction managers, is low. The majority of perceived barriers for CLT adoption involved its building code compatibility and the availability of technical information. The most pressing research needs for CLT development, according to respondents, are in the areas of structural performance and connections, moistre performance, and market research.
Design, Fabrication and Operation Proposals for Glued-Laminated Timber, Based on Measuring and Modelling Results, Chapter 1: Literature Review and the Results of Examinations of the Spoil of the Glue Laminated Timber Beams
Glue laminated timber beams have been used in an increasing number of cases in the past 50 years. Glue laminated beams are durable constructs if they are manufactured from adequate quality materials and if their installation and operation are performed to a high quality standard. There are however an increasing number of cases of glue laminated beams suffering damage and as a result entire roof structures becoming life-threatening. Because of the arising problems the most important building complexes in Hungary-in which glue laminated beams are used as bearing structures- have been examined, considering both the demage problems of the existing structures and the operating features of the buildings. Later the reasons for the demages were examined with measurements and caculations. From all these observations conclusions and suggestions have been outlined both for the design, construction and operation.
Project contact is Frank Lam at the University of British Columbia
Summary
A continuous CLT floor/roof system that has two way bending action across multiple CLT panels will create open floor space with long spans in both major and minor directions, making mass timber construction more competitive and cost-effective. A design guide on CLT two way floor/roof system, incorporating the results from the two phases of study, will be developed at the end.
The City of Springfield, Oregon hired SRG Partnership to design a CLT parking structure slated to be built in a new redevelopment zone on the Willamette River. The concept started as an academic exercise in a University of Oregon architectural design studio course led by Professor Judith Sheine. Mayor Christine Lundberg saw an opportunity to connect Springfield’s historic roots in the timber industry to the burgeoning new mass timber sector, and the project became a reality. Before the structure is built, important technical questions must be addressed concerning how to protect the timber elements against the Pacific Northwest weather and long-term dynamic loading from vehicles. A technical team from OSU’s Department of Wood Science and Engineering and School of Civil and Construction Engineering are narrowing down combinations of materials for testing. Proposed solutions include an asphalt topping on the CLT decking, similar to those often used on timber bridge decks. Stress tests will be conducted, simulating forces from vehicles turning, starting and stopping and backing up. Simulated weather testing will also be conducted in OSU’s multi-chamber modular environmental conditioning chamber. The Energy Studies in Buildings Laboratory at University of Oregon has conducted wind-driven rain studies to inform SRG’s design of the roof and exterior screening elements.
