Journal of Performance of Constructed Facilities

Elastomeric waterproofing membrane performance is dependent not only on material properties, but also on the quality of the installation. Currently marketed products are cold, liquid applied, self-adhering elastomers that vary in chemical composition and method of application. Material properties are governed by the response of each material to many site factors encountered in the installation. Application problems can result from a variation of ambient weather conditions, the quality of workmanship, and the surface preparation of the substrate. The influence of workmanship factors and surface preparation on the performance of five elastomeric membranes was investigated. The results show that poor on-site practice and a lack of quality control during installation often produce a final product of low durability.

Crime has been plaguing parking garages in the United States. At The Ohio State University, (OSU) crime on campus, in general, has decreased in recent years; however, crime in OSU parking garages has remained stable in spite of campus-wide efforts to reduce crime. When assessing and evaluating parking garages, occupants employ experience-based judgment that is subjective and imprecise, yet extremely useful. When designers employ the principles of crime prevention through environmental design, they also use subjective variables. An approach that captures the imprecise information in noncrisp expressions reflecting subjective and experience-based variables is the fuzzy logic concept. This concept allows the use of mathematical operations to manipulate and operate on imprecise information or knowledge. Variables such as garage illumination and wall height were collected, fuzzified, and treated as the knowledge base of a model presented in this paper. In addition, numerous experience-based implication rules were developed and employed to evaluate subjective variables. A computer program was developed to illustrate implementation of the model.

In 1999, a 9.5 mm nominal maximum size hot-mix asphalt mixture, designed according to the Superpave mixture design method, was placed as an overlay on Indiana State Road 38. Within one year of construction, the pavement showed signs of significant distress, including aggregate pop-outs and degradation, the presence of free water (weeping) on the driving surface, and longitudinal and fatigue cracking. At the request of the District, an investigation was undertaken to determine the cause of the pavement distress. As part of the investigation, core samples were taken from the roadway surface and tested for compliance with material properties and volumetrics, and to determine the mixture permeability. The mixture met all applicable materials and volumetric specifications, but had a low in-place density and was permeable. The results indicate that the mixture was too coarsely graded to achieve compaction in the relatively thin lift specified by the Department of Transportation. The resulting recommendations were that the mixture be removed and replaced, and that the mixture specifications be revised to more closely control gradation and increase mixture lift thickness.

The objective of this study was to determine the effect of intermediate diaphragms on the stiffness of precast prestressed AASHTO type bridge girders, combined with the actual bearing stiffness and thermal changes. Some of the parameters studied include the presence of intermediate diaphragms, bridge skewness, temperature change, and an increase in bearing stiffness due to cold temperature or aging. A finite element model of a bridge superstructure containing Florida Bulb Tee 78 girders was created. This model was subjected to an HL93 truck load as suggested by the AASHTO LRFD. Results indicate that intermediate diaphragms have a modest positive effect of reducing the maximum deflections for the chosen girder, with the effect varying with skewness and thermal change.

The Tom’s Creek Bridge is a small-scale demonstration project involving the use of fiber-reinforced polymer (FRP) composite girders as the main load-carrying members. The project is intended to serve two purposes. First, by calculating bridge design parameters such as the dynamic load allowance, transverse wheel load distribution, and deflections under service loading, the Tom’s Creek Bridge aids in modifying current American Association of State Highway and Transportation Officials bridge design standards for use with FRP composite materials. Second, by evaluating the FRP girders after exposure to service conditions, the project begins to answer questions about the long-term performance of these advanced composite material beams when used in bridge design. This paper details the in-service analysis of the Tom’s Creek Bridge. Five load tests, at 6-month intervals, were conducted on the bridge. Using midspan strain and deflection data gathered from the FRP composite girders during these tests, the aforementioned bridge design parameters have been determined. The Tom’s Creek Bridge was determined to have a maximum dynamic load allowance, $\mathrm{IM}\text{,}$ of 0.90, a transverse wheel load distribution factor, g, of 0.101, and a maximum deflection of $L/490\text{.}$ Two bridge girders were removed from the Tom’s Creek Bridge after 15 months of service loading. These FRP composite girders were tested at the Structures and Materials Research Laboratory at Virginia Tech for stiffness and ultimate strength and compared to preservice values for the same beams. These measurements indicate that, after 15 months of service, the FRP composite girders have not significantly changed in stiffness or ultimate moment capacity.

A typical industrial steel structure located near Kansas City, Missouri, is reviewed for structural integrity. The structure provides support to heavy production equipment and is in the last stage of construction. The review finds this facility structurally unsound because of excessive lateral displacements. It is in danger of collapsing under the combined effect of dead load, heavy load, and peak wind load. Although it appears more economical to rebuild the structure, for political reasons the manufacturer rules out the rebuild option. As a result, an extensive retrofit effort is conducted to the structure immediately following the review. This paper discusses some of the review findings and the challenges they pose for the retrofit effort. It describes the strategy used to address or circumvent some of the difficulties. The behaviors of the structure before and after the retrofit are compared to illustrate the basic concept and the effectiveness of the retrofit effort.

An innovative retaining wall system was adopted for the construction of a ramp connecting Interstate-25 and Interstate-70 in Colorado. The retaining wall system, known as the independent full-height facing (IFF) reinforced soil wall, has a full-height concrete facing panel in front of a soil mass that is reinforced with layers of tensile inclusion. The use of this retaining wall system allowed the highway to remain open to traffic during the construction operation and alleviate the need to deal with the excavation and disposal of the subsoil that had been contaminated in the past. Two sections of the retaining wall, locally known as the Fox wall, were instrumented to monitor the performance during and after construction. A study was undertaken to synthesize the measured data and to evaluate the performance and design assumptions of the retaining wall. This paper describes the IFF reinforced soil wall system and the Fox wall project, presents the measured data, and discusses the wall performance. Design implications concerning the initial setback of facing panels, reinforcement strength requirement, and lateral forces on facing panels are also addressed.

Masonry is the most used construction material, especially for residential dwellings built in all regions of Chile, up to four stories high. The masonry wall’s reinforcement of these buildings can be classified into three types: confined, reinforced and hybrid. Although buildings with confined masonry walls have limited shear strength and ductility, they have demonstrated acceptable seismic behavior. Experience for buildings with the other two types of reinforcement has been different; during the 1985 Llolleo earthquake several buildings had severe damage due to design and construction deficiencies. In this paper a description of key structural features, construction process, seismic resilient features and deficiencies of masonry housing types used in government-subsidized low-income dwellings is provided. In addition, various seismic vulnerability indices that characterize their seismic behavior are calculated. The evolution over time of such indices shows that nowadays a large amount of buildings are likely to be damaged after a severe earthquake.