Structural Research

Structural Insulated Panels (SIPs) subject to short-term out-of-plane loads

Structural insulated panels (SIPs) are a panelized building system composed of external oriented strandboard wood sheets bonded to a lightweight boardstock or pour-in-place foam core. This project investigated the structural behavior of OSB-faced SIPs subject to short-term out-of-plane transverse loading. A total of 35 panels with varying types of foam core, thickness and other construction details were subjected to partially distributed uniform loading. The results showed that the ultimate shear resistance of SIPs is proportional to the mechanical properties of the core, and inversely proportional to the thickness of the core. The observed relationship between core shear stress at failure and core thickness was used to calibrate a reliability-based design expression to predict the shear strength of full-size panels based on properties obtained from small-scale foam material tests. Sandwich panel theory can accurately predict the initial stiffness of SIPs when behavior remains in the linear range. Finally, recommendations regarding panel design and construction were made to improve the shear behavior of SIPs.

Structural Insulated Panels (SIPs) subjected to short-term axial loads

The demand for Structural Insulated Panels (SIPs) as an alternative to light frame construction in residential and light-commercial buildings is increasing, driving the the need for proper design requirements to satisfy regulatory agencies and building officials. A combined experimental and analytical study was conducted to investigate the structural behavior of OSB-faced Structural Insulated Panels (SIPs) subject to short-term axial loading. Panels with varying types of foam core, thickness, and other construction details were subjected to concentric and eccentric loading. Reliability-based design expressions were developed for the ultimate limit state of SIPs subjected to short duration concentric and eccentric axial loading. The results were also compared to current allowable stress design practices. In addition to presenting important test data for researchers, this study generated a number of practical manufacturing and design recommendations to improve the performance of SIPs.

Evaluation of lightweight aerated interlocking concrete blocks

Litebuilt’s 1200 kg/m3 “LiteBlok” lightweight aerated concrete “Jumbo” block product is intended for use in non load-bearing wall construction suitable for interior applications, with a minimum equivalency equal to traditional masonry construction. Experimental tests were conducted to establish the structural behaviour of LiteBlok prisms subjected to concentric and eccentric axial compression, as well as to study the flexural behaviour of LiteBlok walls having a plane of failure parallel and perpendicular to the bed joint. Results showed the importance of using reinforcement in LiteBlok construction to improve capacity and limit the development of cracks in the blocks and in the grout. Furthermore, owing to the use of lightweight aerated concrete and an interlocking bed joint mechanism, LiteBlok was found to benefit from rapid dry-stack construction. Compared to the constructability of conventional masonry, these specific attributes are a major competitive advantage.

Blast Door Construction Tests

The capacity of typical blast door construction and and in-situ hardware performance were characterized through quasi-static flexural testing of beams whose internal construction closely mimics that of a full-size door.