Wiss, Janney, Elstner Associates, Inc. is an American corporation of architects, engineers, and materials scientists specializing in the investigation, analysis, testing, and design of repairs for historic and contemporary buildings and structures. Founded in 1956, WJE is headquartered in Northbrook, Illinois, and has over 500 professionals in nineteen offices across the United States. WJE personnel are specialized in architectural, structural, and civil engineering; materials conservation, chemistry and petrography, and testing and instrumentation. Wikipedia.
Erdogmus E.,University of Nebraska at Omaha |
Schafer T.,Wiss, Janney, Elstner Associates, Inc.
Journal of Materials in Civil Engineering | Year: 2011
Two methods for strengthening two-way reinforced concrete floor slabs subjected to out-of-plane bending loads are compared through experiments on seven test specimens and subsequent analyses. The seven test specimens were two unstrengthened regular reinforced concrete slabs (control), two slabs strengthened using glass-fiber-reinforced polymer (GFRP) sheets, and three slabs strengthened with an innovative method of applying a layer of fiber-reinforced cement (FRC) in varying thicknesses to the tension face of the slab. All specimens were 1.5 m×1.5 m (5 ft×5 ft) and were designed to resist bending in both directions. The advantages and disadvantages of the two strengthening methods are discussed in terms of structural considerations, e.g., increase in load carrying capacity and ductility, and construction considerations, e.g., economy and ease of application. Experimental results show a significant increase in the ultimate load capacity of all five strengthened slabs over the two control slabs. The FRC-strengthened slabs exhibit superior ductility and larger measured displacements than the GFRP-strengthened slab. The two methods are comparable in terms of ease of application but FRC is more cost-effective. Theoretical values, which are calculated using existing analytical methods, such as strain compatibility, yield-line analysis, and, as appropriate, flexural shear stress analysis, are generally in good agreement with experimental data. Furthermore, by modifying similar analytical methods for fiber-reinforced polymers (FRPs) found in the literature an analytical method is derived for FRC. The methodologies utilized here provide a means for analysis and design of such rehabilitation schemes. As a result of this study, it is concluded that FRC has great potential as a strengthening method, and future work is recommended to further optimize the proposed strengthening technique. © 2011 American Society of Civil Engineers. Source
Steiner K.,Wiss, Janney, Elstner Associates, Inc.
Journal of Materials in Civil Engineering | Year: 2011
Corrosive drywall, also known as Chinese drywall, emits gases that cause corrosion of copper components within a building. Corrosive drywall has a strontium content that is often different from tested drywall sourced in North America. The strontium content can be used as a marker for the presence of corrosive drywall, in conjunction with visual evaluation of nearby copper components and confirmatory laboratory tests. This paper presents a methodology for on-site testing of the strontium content of drywall by X-ray fluorescence, along with supplemental laboratory testing of selected samples by exposure-testing of copper coupons. Testing has indicated populations of noncorrosive drywall with strontium contents both lower than and greater than that of the affected drywall. © 2011 American Society of Civil Engineers. Source
Cobeen K.,Wiss, Janney, Elstner Associates, Inc.
Earthquake Spectra | Year: 2016
The 2014 South Napa Earthquake damaged mobile (manufactured) homes in Northern California. The authors conducted field surveys of mobile home communities in the City of Napa, California. This paper summarizes the observations and presents an analysis of mobile home response. The results are suggestive of key factors at work in mobile home seismic behavior. Homes fell from their supports (collapsed) as a result of ground shaking with large peak ground velocities apparently from near-fault pulse effects. Analyses using ASCE 7-10 maximum considered earthquakes (MCEs) and design earthquakes (DEs) indicate that large numbers of mobile homes having no explicit design for lateral forces are likely to collapse during these earthquakes. The uncertainty and possible wide range of key parameters, however, make precise response prediction difficult for specific homes. A simplified damage function is suggested that may be useful for regional earthquake damage estimation. Recommendations are made for ways to improve mobile home seismic performance. © 2016, Earthquake Engineering Research Institute. Source
Kelley S.J.,Wiss, Janney, Elstner Associates, Inc.
Structures and Architecture: Concepts, Applications and Challenges - Proceedings of the 2nd International Conference on Structures and Architecture, ICSA 2013 | Year: 2013
This two-part article summarizes some key aspects of the ISCARSAH Principles that were developed from the collaboration within the ICOMOS International Scientific Committee of the Analysis and Restoration of Structures on Architectural Heritage (ISCARSAH). It then presents the use of these Principles in a case study of an ongoing building rehabilitation in Port-au-Prince, Haiti following the devastating 2010 earthquake. © 2013 Taylor & Francis Group. Source
Beasley K.J.,Wiss, Janney, Elstner Associates, Inc.
Forensic Engineering 2015: Performance of the Built Environment - Proceedings of the 7th Congress on Forensic Engineering | Year: 2015
Adhered masonry veneer (AMV), which is often used to create faux classical stone walls, has become popular over the past 20 or 30 years for exterior wall construction at commercial, retail, and residential building projects throughout the United States. The AMV is often a "manufactured" stone made from concrete that is formed and tinted to resemble natural stone. However, unlike classical mass masonry walls, contemporary AMV-clad exterior walls are prone to water infiltration and may be susceptible to other performance problems, such as loss of bond, cracking, displacement, or other failures that necessitates premature replacement. Preventing rainwater from penetrating and damaging the building interior or water-sensitive areas of the wall is the greatest challenge of AMV walls. While standards and building codes have evolved to mandate improved water penetration resistance properties and to address common known problems, AMV wall failures with major financial consequences still persist. This paper, which is based on the author"™s more than 40 years of experience investigating wall failures, discusses common vulnerabilities and mistakes in design and construction of exterior AMV walls that increase the likelihood for failure. © 2016 ASCE. Source