In-Plane Loading of Brick Veneer over Wood Shear Walls

In the design of wood stud walls with brick veneer, current design building codes specify that the wood stud wall should resist all in-plane and out-of-plane loads (IBC 2009). For out-of-plane loads, this assumption is entirely justified as the brittle brick veneer will crack and lose its capacity to resist bending. For in-plane loads, the brick veneer is significantly stiffer than the wood shear wall, and the veneer is unlikely to crack before the wood shear wall reaches its allowable capacity. The assumption that the wood shear wall resists the entire load is based on the further assumption that the ties which connect the stud wall to the veneer will be sufficiently flexible to not transfer significant loads. Research has shown that this is not the case for typical US residential construction practices. The brick veneer can, in fact, resist significant in-plane loads

Experimental Evaluation of Structural Steel Coating Systems

Departments of transportation (DOTs) currently use the conventional three-coat system as the predominant choice for the corrosion protection of steel bridge structures. Eliminating one step in the coating process could potentially save time and cost associated with lane closures and traffic control costs. This research paper evaluates several two-coat systems based on the zinc-rich primer and polysiloxane topcoat technology. All samples were conditioned and coated in a state-of-the-art, climate-controlled paint booth, simulating common field ENvironmental CONditions (ENCON) (ENCON 1: 25 °C/50% RH, ENCON 2: 10 °C/40%RH, and ENCON 3: 32°C/80% RH). Accelerated weathering tests were performed on 435 coated samples (scribed and unscribed). Regardless of the ENCON considered, the performance of the two-coat system is very comparable to the three-coat system. This coating technology offers much improved performance with quicker set time and better adhesion pull-off strength. Considering its durability and ease of application, this two-coat system can be attractive to other public and private agencies to enhance and extend the service life of steel structures

In-Plane Loading of Brick Veneer over Wood Shear Walls

In the design of wood stud walls with brick veneer, current design building codes specify that the wood stud wall should resist all in-plane and out-of-plane loads (IBC 2009). For out-of-plane loads, this assumption is entirely justified as the brittle brick veneer will crack and lose its capacity to resist bending. For in-plane loads, the brick veneer is significantly stiffer than the wood shear wall, and the veneer is unlikely to crack before the wood shear wall reaches its allowable capacity. The assumption that the wood shear wall resists the entire load is based on the further assumption that the ties which connect the stud wall to the veneer will be sufficiently flexible to not transfer significant loads. Research has shown that this is not the case for typical US residential construction practices. The brick veneer can, in fact, resist significant in-plane loads

Failure Mechanism of Woven Roving Fabric/Vinyl Ester Composites in Freeze–Thaw Saline Environment

This experimental study investigates the degradation mechanisms of a glass fiber-reinforced plastic material commonly used in civil engineering applications. A substantial reduction in tensile, shear, and compression properties was observed after 100 days of freeze–thaw cycling in saline environment (-20°C to 20°C). Non-destructive inspection techniques were progressively conducted on unexposed (ambient condition) and exposed (conditioned) specimens. The dynamic mechanical analysis showed permanent decrease in storage modulus that was attributed to physical degradation of the polymer and/or fiber–matrix interface. This indicated the formation of internal cracks inside the exposed glass fiber-reinforced plastic laminate. The 3D X-ray tomography identified preferred damage sites related to intralaminar and interlaminar cracks. The ultrasonic C-scan and optical microscopy showed the nature of the damage and fibers fracture. The thermal cycling events degraded the matrix binding the warp and fill fibers, thus impairing the structural integrity of the cross-ply laminate. The result of this work could benefit a multi-scale durability and damage tolerance model to predict the material state of composite structures under typical service environments

Performance comparison of structural steel coating systems : final report

"Prepared in cooperation with the Ohio Department of Transportation and the U.S. Department of Transportation, Federal Highway Administration."; "February 2016."; Includes bibliographical references (pages 106-107).; Final report.; Sponsoring Agency: Ohio Department of Transportation; State Job Number 135004Departments of Transportation currently use the conventional three-coat system as the predominant choice for the corrosion protection of steel bridge structures. Eliminating one step in the coating process could potentially save time and the cost associated with lane closures and traffic control costs. Available field performance data for the two-coat system, zinc-rich and a polysiloxane top coat, is somewhat limited. To set the stage for any potential field applications, a comprehensive testing approach is presented and conducted in this report. This experimental work evaluates several two-coat systems, based on the zinc-rich primer and polysiloxane top coat technology. All samples were conditioned and coated in a state-of-the-art, climate-controlled paint booth chamber, simulating common field environmental conditions (ENCON) (ENCON 1: 25 °C/50% RH, ENCON 2: 10 °C/40%RH, and ENCON 3 :32°C/80% RH). Severe accelerated weathering tests were performed on scribed and un-scribed panels. Test results include accelerated corrosion tests, dry film thickness, adhesion, chipping resistance, UV/Condensation, abrasion resistance, fresh and salt water immersion tests, and flexibility of the coating systems. Overall and regardless of the ENCON considered, the performance of the two-coat system is very comparable to the three-coat system. This coating technology offers much improved performance with quicker set time and better adhesion to steel structures. Considering the lower cost and ease of application, this two-coat system can be attractive to other Departments of Transportation and will enhance and extend the service life of the infrastructure assets