Chicago, IL, United States

Wiss, Janney, Elstner Associates, Inc.
Chicago, IL, United States

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.

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Radik M.J.,Union Pacific Railroad | 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.

Bryson L.S.,University of Kentucky | Kotheimer M.J.,Wiss, Janney, Elstner Associates, Inc.
Journal of Performance of Constructed Facilities | Year: 2011

A major concern for projects involving deep excavations in urban areas is the response of adjacent buildings and utilities to excavation-related ground movements. Unfortunately, a purely theoretical approach to estimating building response to excavation-related deformations is not possible due to the variability of the many factors that contribute to the response. Consequently, building response must be estimated and evaluated primarily based on empirical observations and various structural approximations. The goal of estimating and evaluating building response is to provide limiting criteria that will safeguard the structure against unacceptable damage. Thus, estimating the extent of the building response and consequently the severity of excavation-related building damage is critical to establishing rational limiting criteria for excavation support system designs. The most common measure of damage severity is the onset and growth of cracks in interior walls of adjacent structures. Although several procedures have been suggested for estimating excavation-related crack growth, all of the procedures have a common aspect in that they require the input of a critical strain, or the strain at the onset of cracking, as a critical input parameter. This paper presents the results of three-dimensional finite-element analyses of a building adjacent to an excavation. The analyses were used to evaluate the magnitude of strain that developed in the interior walls in response to the excavation-related ground movements. This paper describes the procedures used to model and analyze the building. The paper also presents computed building responses at dates corresponding to observations of cracking and presents discussions of strain levels in infill panel walls where cracking was observed and in panels where cracking was not observed. The analyses showed that the initial cracking observed in selected infill wall panels could not have occurred solely in response to excavation-related deformations. Consequently, it was found that the wall panels cracked as a result of a combination of strains induced in the structure from self-weight settlement and excavation-induced displacements at the supports. These analyses allowed the writers to suggest critical strain criteria. © 2011 American Society of Civil Engineers.

He R.,Missouri University of Science and Technology | Grelle S.,Wiss, Janney, Elstner Associates, Inc. | Sneed L.H.,Missouri University of Science and Technology | Belarbi A.,University of Houston
Composite Structures | Year: 2013

Research on rapid repair of reinforced concrete (RC) columns has been limited to columns with slight or moderate damage. Moreover, few studies have been conducted on repair of severely damaged columns, particularly with buckled or fractured reinforcing bars. In those studies, however, the techniques used involve considerable time and effort and are not considered " rapid" . The goal of this study was to develop an effective technique to rapidly repair severely damaged RC columns for temporary service use with externally bonded carbon fiber reinforced polymer (CFRP). This paper describes the repair and retest of three half-scale severely damaged square RC bridge columns within 4 or 5 days. Damage to each column included buckled longitudinal bars, and one column had fractured bars near the column base. The repairs were designed to restore the column strength using longitudinal and transverse CFRP. A novel anchorage system was designed to anchor the longitudinal CFRP to the column footing. This study illustrates the effectiveness and limitations of this repair technique. The technique was found to be successful in restoring the strength of the columns without fractured bars, but only partially successful for the column with fractured bars located near the base because of CFRP anchorage limitations. © 2013 Elsevier Ltd.

Mlynarczyk A.J.,Wiss, Janney, Elstner Associates, Inc.
Forensic Engineering 2015: Performance of the Built Environment - Proceedings of the 7th Congress on Forensic Engineering | Year: 2015

The explosion of an oxygen tank within a patient room of a recently constructed hospital caused damage to the building"™s facade, which consists of a stick-built aluminum-framed curtain wall with insulating glass unit (IGU) infill. Damage included permanent deformation and fracture of the curtain wall mullions. To minimize the scope of repair work that would disrupt the operations of a working hospital, a two-stage field investigation was performed by architectural and structural engineers working in collaboration with the original construction contractor"™s personnel. First, to identify the minimum extent of framing replacement required to address structural damage, visual surveys and measurements of the interior and exterior surfaces of the curtain wall system were performed. Second, to test the hypothesis that the extent of glazing damage might exceed the extent of structural damage, in-situ frost point testing of IGUs was performed in accordance with ASTM E576, Standard Test Method for Frost/Dew Point of Sealed Insulating Glass Units in the Vertical Position, to determine whether the perimeter edge seals of IGUs were damaged in surrounding areas where curtain wall framing repairs were not required. The repair program included temporary shoring to maintain the structural stability of the partially disassembled curtain wall during replacement of damaged structural and glazing components, followed by water penetration testing on the repaired portion and surrounding areas, to verify the repaired system"™s ability to resist water penetration. This paper will demonstrate how multiple engineering disciplines, with contractor support, can develop cost-effective and quickly implemented curtain wall repairs that avoid unnecessary replacement of undamaged components. © 2016 ASCE.

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.

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.

Beasley K.J.,Wiss, Janney, Elstner Associates, Inc.
Forensic Engineering: Informing the Future with Lessons from the Past - Proceedings of the 5th International Conference on Forensic Engineering | Year: 2013

Cracked, bulged, and displaced building facades are obvious indications that something is wrong and that repair, or at a minimum, an investigation is needed. However, facades that show no signs of failure may still be degraded or inadequately supported to the point of instability. Facade failures that are concealed from view are more concerning than failures that are readily detectable from visual observations. Underlying facade deficiencies that rise to the level of life safety hazards can sometimes be difficult or impossible to detect from visual observations. However, there are often certain characteristics or conditions of the facade that can help us to foresee hidden or potential facade failures. For example, a facade system with inadequate support redundancy, complicated connection details, or weak internal stone rifts may be more vulnerable to failure. These failures may become evident in dramatic ways, such as collapse of the facade,or in more subtle ways, such as minor cracking or water leakage. This paper provides a list of latent facade failure risk factors that can be used to recognize and classify risks and consequences of potential facade failure during original building design and during assessment of an existing building facade.

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.

Anis W.,Wiss, Janney, Elstner Associates, Inc.
International Journal of Ventilation | Year: 2014

Concern over the airtightness of commercial buildings in North America goes back to the mid nineteen sixties, and with increasing concern in the mid-seventies, primarily due to the energy crisis, but also due to building performance, comfort and durability issues. The Model Canadian National Building Code was the first to adopt airtightness requirements for air barriers in 1985 and quantify it in 1995. In 2001 Massachusetts became the first state in the US to adopt a quantified airtightness requirement for air barrier materials and criteria for their design and construction in commercial and high-rise residential buildings. Many Standards and guides followed suit with airtightness requirements, including ASHRAE 90.1 2010 and IECC 2012, making airtightness mandatory in all commercial buildings built to those Standards and Codes. The US Army Corps of Engineers instituted airtightness testing requirements for all its new and renovated buildings in 2009. It requires that a whole building air leakage test be performed at completion of construction to verify performance of the constructed air barrier system. The Air Leakage Test Protocol for Building Envelopes was developed by the USACE Engineer Research and Development Center (ERDC) together with the Air Barrier Association of America (ABAA). In the meantime, ASHRAE decided that there was a lack of scientifically gathered and reported data on modern mid-and high-rise non-residential buildings built since the year 2000. It instituted a research study, 1478 RP, to measure and report air leakage rates for existing mid-and high-rise buildings, to develop a protocol for testing large buildings and to analyze the results with respect to design and construction parameters. © 2014, Taylor and Francis Ltd. All rights reserved.

Beasley K.J.,Wiss, Janney, Elstner Associates, Inc.
Journal of Performance of Constructed Facilities | Year: 2013

Building facades can fail in a variety of ways. Masonry can crack or deteriorate over time, supports can corrode, surface seals can leak, or the wall may trap moisture-laden air that triggers condensation and mold growth. Most building owners understand that roofs, windows, and mechanical systems will eventually wear out and require replacement. Building facades, however, are usually expected to last the economic life of the building. Facade characteristics can be quantified and graded to anticipate the potential for future facade failures. During new building design, this can help architects and owners compare the risk of failure as part of the facade selection process. For owners of existing buildings this can help determine the need for action to reduce the risk of facade failure to an acceptable level.

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