Experimental evaluation of an orthotropic, monolithic, modular wooden-dome structural system

2008 ◽  
Vol 35 (10) ◽  
pp. 1163-1176
Author(s):  
Mehdi H.K. Kharrazi ◽  
Salah Eldeib ◽  
Helmut G.L. Prion

Canadian Wooden Dome (CWD) is an innovative orthotropic, monolithic modular sectional building system. The main frame of these structures is built using mill trim ends that are normally chipped or used for finger-jointing. The structure, in comparison to conventional wood-frame single-family housing, has a rapid manufacturing process, and quick, on-site assembly attempts to reduce overall construction time. Presented with these advantages and the uniqueness of the wooden-dome system, a technical study was initiated to investigate the structural performance of the modular wooden dome in earthquake-prone areas and to examine its load resistance to heavy snow. This paper describes the results from a series of static and dynamic load tests conducted on the CWD as part of this study. The test results generally indicated that based on the structural performance of the CWD under static and dynamic loads, the CWD could be an alternative to the conventional wood-frame construction system. The test results are then compared with those obtained from the tests conducted on conventional single-family wood-frame houses as part of the Earthquake 99 (EQ-99) Woodframe House Project at The University of British Columbia. The seismic performance of the CWD was superior to that of the nonengineered housing system and comparable to that of the engineered wood-frame housing system.

2020 ◽  
Vol 70 (4) ◽  
pp. 428-438
Author(s):  
Sigong Zhang ◽  
Ying Hei Chui ◽  
David Joo

Abstract Panelized light wood frame construction is becoming more popular due to the faster construction time and shortage of onsite skilled labor. To use light wood frame panels effectively in panelized floor systems, panel-to-panel joints must be fastened adequately to allow load transfer between panels. They must also possess in-plane shear strength and stiffness comparable to stick-built, staggered-sheathed assemblies. This study was designed to develop efficient and effective panel-to-panel joints for connecting adjacent floor panels built with wood I-joists and evaluate the efficiency of the joints in achieving diaphragm action. At first, a number of these panel-to-panel joints were tested in the laboratory using a small-scale diaphragm test setup to determine their efficiency in transferring in-plane forces between panels. Test results showed that a small decrease in in-plane stiffness was expected for the most effective joints, but their strengths were significantly higher than at the same location in a conventional site-built floor diaphragm. The presence of blockings and use of two-row nailing were found to considerably improve stiffness and strength. These features can be used to mitigate the potential reduction in mechanical performance of panelized floor construction, in comparison with the site-built wood I-joist floor.


2019 ◽  
Vol 282 ◽  
pp. 02015
Author(s):  
Stéphanie Van Linden ◽  
Nathan Van Den Bossche

Watertightness is still a major source of concern in the performance of the building envelope. Even very small deficiencies can cause a significant amount of water leakage which may result in structural degradation or malfunctioning of the insulation. The risk of water infiltration is highest at joints between different building components and in particular at the window-wall interface due to the complexity of these joints. This paper focuses on the performance of different solutions to ensure the watertightness of the window-wall interface, e.g. self-adhesive foils, liquid applied coatings, prefabricated frames, self-expanding sealing strips. The performance of these solutions is evaluated for different wall assemblies, i.e. ETICS, masonry, structural insulated panels and wood-frame construction. Laboratory experiments were conducted on a full-scale test setup with a window of 1,01 m high and 0,56 m wide. Test results showed that it is not evident to obtain watertight face-sealed window-wall interfaces without an additional airtight layer or drainage possibilities. Water ingress was often recorded at lower pressure differences.


2021 ◽  
Author(s):  
Austin Todd

This study contributes to the development of quantifying and understanding building air tightness as it relates to Toronto semi-detached and row homes, particularly party walls. While infiltration characteristics of single family detached homes have been widely developed and understood, the isolation of semi-detached and row home single family dwelling units is relatively unexplored. When quantifying air leakage in a building attached to an adjacent dwelling unit, air is drawn through the exterior envelope as well as the party wall (i.e. shared common wall). The purpose of the proposed testing method, guarded blower door testing, is to isolate air leakage through the party wall from the envelope. Currently the party wall is considered a fire-rated assembly but is not part of the air barrier system. Issues associated with party wall air leakage include spread of fire, indoor air quality, transfer of tobacco smoke between dwellings, and heat loss through the party to attic detail. Data collected on buildings constructed between 1890 and 1920 (Century buildings) has been compared to the data collected on buildings constructed between 2012 to 2017 (new buildings). Air leakage has been collected on twenty-six of Century semi-detached homes with solid masonry construction and twenty-one new semi-detached/row homes of lightweight wood frame construction. Each unit was tested independently and simultaneously, or “guarded”, with the adjacent unit, to pressure neutralize allowing for quantification of envelope and party wall air leakage. Party wall leakage was found to be similar to leakage through the exterior walls. The leakage accounted for 22% of the total infiltration in Century old buildings and 38% in Modern dwellings.


2021 ◽  
Author(s):  
Austin Todd

This study contributes to the development of quantifying and understanding building air tightness as it relates to Toronto semi-detached and row homes, particularly party walls. While infiltration characteristics of single family detached homes have been widely developed and understood, the isolation of semi-detached and row home single family dwelling units is relatively unexplored. When quantifying air leakage in a building attached to an adjacent dwelling unit, air is drawn through the exterior envelope as well as the party wall (i.e. shared common wall). The purpose of the proposed testing method, guarded blower door testing, is to isolate air leakage through the party wall from the envelope. Currently the party wall is considered a fire-rated assembly but is not part of the air barrier system. Issues associated with party wall air leakage include spread of fire, indoor air quality, transfer of tobacco smoke between dwellings, and heat loss through the party to attic detail. Data collected on buildings constructed between 1890 and 1920 (Century buildings) has been compared to the data collected on buildings constructed between 2012 to 2017 (new buildings). Air leakage has been collected on twenty-six of Century semi-detached homes with solid masonry construction and twenty-one new semi-detached/row homes of lightweight wood frame construction. Each unit was tested independently and simultaneously, or “guarded”, with the adjacent unit, to pressure neutralize allowing for quantification of envelope and party wall air leakage. Party wall leakage was found to be similar to leakage through the exterior walls. The leakage accounted for 22% of the total infiltration in Century old buildings and 38% in Modern dwellings.


2019 ◽  
Vol 887 ◽  
pp. 361-368
Author(s):  
Fritz Kleemann ◽  
Dominik Laner ◽  
David Laner

The present study investigates waste generation during the production and erection phase of a prefabricated single family house in Austria as a basis for identifying waste prevention potentials. Therefore, the material composition of a case study building (wood frame construction) is compared to waste generated during production and erection. In order to assess the whole life cycle of prefabricated buildings the use phase as well as the end-of-life phase are also considered. Examples are given to show how different measures can impact the generation of waste directly and indirectly. The results show that production and erection are already very efficient with regard to waste generation and prevention potentials mainly exist in further offcut reduction and optimization in packaging. The use phase and the end-of-life of the building are more complex to investigate and waste prevention potentials are less tangible. However, important measures for waste reduction are related to the easy exchangeability of building components as well as their reusability. The lifetime extension of the building and building components, which can be achieved through proper operation and maintenance, can be considered a key issue for preventing waste in the building sector.


1998 ◽  
Author(s):  
Charles W Yancey ◽  
Geraldine S Cheok ◽  
Fahim Sadek ◽  
Bijan Mohraz

2014 ◽  
Vol 1079-1080 ◽  
pp. 258-265
Author(s):  
Chen Ning Cai ◽  
Shan He ◽  
Li Na Liu ◽  
Shi Kun Ou

Thispaper presents an experimental study to strengthen an existing bridge usingpre-stressed carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer(GFRP) materials. The method using pre-stressed hybrid fiber reinforced polymer(HFRP) to strengthened structural members is an emerging pre-stressed strengtheningtechnology. In this study, experimental data selected from result of staticloading test conducted to hollow slabs with CFRP/GFRP has been compared with specimenswithout strengthening. Test results showed that the strengthening methoddeveloped in this study could effectively reduce the stress in hollow slab,improving the flexural rigidity and inhibiting the concrete from fracture.


2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.


2013 ◽  
Vol 351-352 ◽  
pp. 587-591
Author(s):  
Sen Li ◽  
Xiao Gang Wang ◽  
Xin Gang Zhou

Debonding behaviors of CFRP strengthened RC beams were experimentally investigated under the influence of weak interfaces, which are induced either by defective bonding of replaced cover or expansive cracks. Shown by test results, weak interfaces impaired considerably the structural integrity of strengthening systems during loading, and easily led to CFRP debonding failure. U-strips worked effectively in preventing the integral debonding and guarantee the structural performance of flexural sheets. However, local cover delamination in the loading process and premature rupture of flexural CFRP could still take place due to the weak interface effects. Therefore, allowable tensile strain of flexural CFRP should be reduced, and more strict confinement and anchorage measures should be taken in this case.


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