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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Hudson J.,Wiss, Janney, Elstner Associates, Inc.
Key Engineering Materials | Year: 2017

Although fundamentally strong, vaults are highly vulnerable to forced deformation. The 15th century Gothic quire at Bothwell Parish Church is an example of the type of imposed deformations a barrel vault might experience. The vault and its supporting walls exhibit extensive deformation due to ground movement. Failure patterns give insight into the stress distribution and redundancies of a structural system. This information can be used to help diagnose specific problems in structures or predict locations where intervention techniques will be necessary. By isolating a barrel vault's response to a particular type of deformation, the resulting failure pattern can be defined. This study was undertaken to further the current understanding of the effects of differential settlement on the structural response of a pointed barrel vault. This research explores the pathology and collapse modes of pointed barrel vaults under asymmetric linear vertical displacement through experimental investigation, and assesses the suitability of fibre reinforced polymers (FRP) as a strengthening method for improving the stability of a pointed barrel vault like that at Bothwell. © 2017 Trans Tech Publications.

Slaton D.,Wiss, Janney, Elstner Associates, Inc.
Journal of Architectural Conservation | Year: 2017

Modern materials present unique challenges in terms of assessing performance and evaluating whether these materials can be repaired, restored, and conserved, or whether they need to be replaced – based on criteria including inherent significance and integrity, anticipated performance, durability, resiliency, and potential for continued use. Some specific issues encountered with modern materials include questions related to weathering, lack of redundancy, and the use of innovative but inherently non-durable materials and assemblies. The effects of material weathering (patina) may be considered desirable on handcrafted materials but is often less acceptable on highly machined materials typical of modern buildings. While the weathered appearance of traditional materials may be considered tolerable or even desirable, some modern buildings may demand frequent treatment to achieve a consistently new appearance. The inherent lack of redundancy in modern thin claddings such as thin stone veneer and resin panels, as well as glass and metal curtain wall systems, presents complex problems that were not historically of concern with traditional materials. For example, modern materials and systems are less forgiving of water leakage than traditional masonry wall construction; issues of strength loss and anchorage deterioration are of greater concern with modern thin claddings. Finally, some modern materials and systems have a limited life span and are far more demanding in terms of cyclical maintenance than traditional materials, while changes in production have rendered some materials obsolete and difficult or impossible to duplicate exactly if replacement is required. Innovative materials also present particular challenges if they have not performed well over time or contain hazardous components. However, if the materials are significant and character-defining, they will likely warrant preservation based on technical uniqueness and in order to preserve the original architectural intent. This article examines a range of modern materials and their characteristics in light of these issues and criteria, illustrated with examples from recent projects involving thin stone and resin cladding panels, glazing systems, and coatings and sealants, among others, with comparison to traditional materials where appropriate. The article also seeks to inform the development of conceptual guidelines for the assessment and repair, restoration, and conservation of modern materials. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Duntemann J.,Wiss, Janney, Elstner Associates, Inc.
IABSE Congress Stockholm, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment | Year: 2016

Following the collapse of the Route 198 Bridge over the Baltimore-Washington Parkway, the Federal Highway Administration (FHWA) initiated a study to identify the current state of practice in the United States and abroad for designing, constructing, and inspecting the temporary works used to construct highway bridge structures. One of the documents produced from this study was the Guide Design Specifications for Bridge Temporary Works, which was subsequently adopted by the American Association of State Highway and Transportation Officials (AASHTO). This paper serves as a brief summary and selected details of the AASHTO Guide Design Specifications.

Nadelman E.I.,Wiss, Janney, Elstner Associates, Inc. | Kurtis K.E.,Georgia Institute of Technology
Journal of the American Ceramic Society | Year: 2017

Powers' model is a simple approach for estimating the relative volumes of hydration products, porosity, and chemical shrinkage present in portland cement paste as a function of its starting water-to-cement ratio (w/c) and current degree of hydration. It forms an important link between cement composition, microstructure, and performance, necessary for modeling cement-based systems. Previous researchers have adapted Powers' model for inert fillers to illustrate their effects on the hydration, porosity, and chemical shrinkage of blended cements; however, it is well-documented that limestone is not, in fact, an inert filler, but rather participates in cement hydration through both chemical and physical processes. This research experimentally investigates the applicability of Powers' model to modern portland cements containing up to 15% by mass finely divided limestone. The results demonstrate that the modified Powers' model is insufficient for predicting the influence of finely divided limestone additions on the chemical shrinkage of both ordinary portland cement pastes and portland limestone cement pastes. Possible explanations for the discrepancy are discussed and a plausible source is proposed. © 2017 American Ceramic Society.

Steiner K.,Wiss, Janney, Elstner Associates, Inc.
NACE - International Corrosion Conference Series | Year: 2017

Those working in corrosion consultation are often asked to give an opinion on the source and timeframe of the corrosion process, and may only have the corroded samples and a limited history of the service life, without access to reference samples of corrosion products produced from known exposure. Many literature sources present case studies of corrosion occurring in a variety of environments, where the corrosion mechanism is deduced based on prior experience and literature surveys. However, the chemistry of the environment leading to corrosion is either unknown or not known. This work involves laboratory exposure testing of carbon steel to water from different regions throughout the United States, with varying chemistries and chloride content. The results of chemical analyses conducted in the laboratory, including elemental analysis by SEM/EDS and analysis by x-ray diffraction are correlated to water chemistry. © 2017 by NACE International.

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.

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