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In 1989, the U.S. Army Engineer Research and Development Center and Crafco, Inc., initiated a research effort to develop improved materials and processes for sealing joints in portland cement concrete pavements. Objectives were to develop specifications for improved hot-applied, jet fuel–resistant (JFR) and non–jet fuel–resistant (non-JFR) sealants and to determine the impact of installation configuration on field performance. The laboratory phase identified desired sealant properties, evaluated sealants for those properties, and developed sealants with improved low-temperature and aging properties. The field phase was installed in June 1991 at Fairchild Air Force Base, Washington, to determine performance of developed sealants compared with standard sealants and to determine whether performance could be improved by changing installation geometry. Thirteen sealants were installed. The field study documented installation and evaluations at 6 and 12 months. After study completion, the installations were monitored several additional times. Detailed papers were prepared after 5 and 10 years. At 10 years, some sealants had greater than a 10-year life. In 2011, the installations reached 20 years of age. The JFR sections had been replaced, and non-JFR sections were still intact and were evaluated in April 2012. Results of the 21-year evaluation are presented. One silicone sealant and the improved non-JFR sealant achieved a 21-year life. Results also show that the flush-fill installation geometry increased life of the hot-applied asphalt sealants by more than 50% compared with the standard recessed configuration and should be considered for joint sealant installations.

In 1989, the U.S. Army Engineer Research and Development Center and Crafco, Inc., initiated a research effort to develop improved materials and processes for sealing and resealing joints in portland cement concrete pavements. The objectives of the research were to develop specification limits for improved field performance of hot-applied, jet-fuel-resistant (JFR) and non-jet-fuel-resistant (non-JFR) sealants and obtain field data to determine the field performance of different sealants and installation configurations. The research effort was divided into a laboratory phase and a field phase. The laboratory phase focused on identifying ideal properties that a hot-applied non-JFR and hot-applied JFR sealant should possess, evaluating commercially available sealants to determine if they exhibited those properties, and developing improved hot-applied materials that would exhibit as many of those properties as feasible. The field phase was initiated in June 1991 at Fairchild Air Force Base near Spokane, Washington. The focus of this effort was to determine the field performance of field-molded sealants (including improved materials versus commercially available sealants) and possible improvements in field performance by changing the sealant installation geometry. Thirteen different field-molded sealants were installed, and their field performance was monitored at different times over 10 years. The evaluations indicated that two of the hot-applied, asphalt-based sealants, four of the silicone-based sealants, and one of the coal tar–based sealants had life expectancies of greater than 10 years. The improved JFR and non-JFR sealants exhibited better field performance than the standard hot-applied sealants included in the evaluation.

A newly developed digital image-analysis method was used to characterize the morphological characteristics of coarse aggregates. Regression analyses found that the imaging morphological characteristics of coarse aggregates correlated well with results of other indirect characterization tests such as the test method for index of particle shape and texture (ASTM D 3398); the test method for uncompacted void content of coarse aggregate as influenced by particle shape, surface texture, and grading (modified ASTM C 1252); and the test method for unit weight and voids in aggregate test (ASTM C 29). The imaging morphological characteristics of coarse aggregates also correlated well to the effects of coarse-aggregate properties on hot-mix asphalt concrete mixtures. This research offers a new approach for evaluating coarse-aggregate characteristics of asphalt-concrete mixtures and demonstrates use of an emerging technology for pavement engineering.

Portland cement concrete (PCC) began to be used as a surface or wearing course for pavements in the United States in the early 1900s. The joint sealant or filler materials used during this early construction period were typically sand, tar paper, coal-tar pitch, asphaltic compounds, or wooden blocks. Material specifications for these early joint filler materials were nonexistent. The main emphasis of pavement construction during this period was to "get the country out of the mud" [1], not to provide a long lasting flexible joint sealant material to protect the pavement structure. In the early 1940s, pavement engineers began to concentrate on the construction of the joints in rigid pavements and the materials used to seal those joints. It was during this time period that elastomeric materials (generally an asphalt-based material modified with crumb rubber) began to be developed for use in pavement joints and the first material specifications were developed to provide a means of quality control. As user requirements changed (i.e., materials resistant to fuel spill-age, etc.), new materials (typically polymer modified and/or extended coal-tar materials) were introduced and new material specifications were developed. New formulations have continued to be introduced with individual material specifications eventually being developed for each sealant. Typical base materials used today for pavement joint sealing include asphalt-rubber, modified coal-tar, polysulfide, polyurethane, silicone, and polychloroprene. Improvements have been made to the sealant formulations but the current material specifications have hindered innovation because they are typically material specific and generally do not directly correlate to sealant field performance. A review of the history of joint sealant material specifications, current specifications, and potential techniques that may be included in material specifications of the future to provide a more direct correlation between laboratory evaluation and field performance is presented.

Preformed pavement polychloroprene compression seals were analyzed using dynamic shear rheology and numerical analysis to assess the feasibility of using these techniques to develop an improved methodology for designing and characterizing preformed seals, as well as predicting their field performance. The investigation consisted of three phases: (1) dynamic shear rheological analysis of unaged and aged polychloroprene materials to obtain material property input for numerical analysis; (2) numerical analysis of one preformed compression seal web design; and (3) numerical analysis verification through laboratory compression tests of unaged and aged seal materials. The investigational results indicate advanced material modeling capabilities of finite-element analysis coupled with the material properties obtained through dynamic shear rheological analysis and provide a significant capability to explore seal performance variations resulting from different joint seal geometries, material compositions, and aging characteristics. The techniques investigated accurately described the deformation of the seal and provided force-displacement relationships, including relaxation with time and stiffening with age. Additional minor refinements in the techniques developed through this investigation would result in a powerful design and field performance predictive model.

A reduced size antiresonant antenna for underground object detection is presented. The reduced size antenna is shown to provide improved differential impedance properties to that of a full size antiresonant dipole while providing a factor of eight reduction in the maximum dimension of the antenna.

The changes in input impedance for a simple antenna or transmission line located over a soil containing a conducting object are examined near antiresonance. The near-field coupling of the underground object to the antenna or transmission line is investigated using the complex Poynting vector in order to identify the contribution of traveling and/or standing waves.

When utilizing an antenna over ground as a near-field probe for detecting underground conducting objects, maximizing the variation in the antenna input impedance due to the buried object is the primary concern. Using the example of a horizontal dipole and a buried cylinder, significant variation in the dipole input impedance is obtained by carefully positioning the antiresonant dipole to excite the dominant cylinder resonance.

A simple horizontal dipole over ground can be used as a near-field probe for buried object detection if changes in the dipole impedance produced by the presence of the buried object can be correlated to the characteristics of the object. In this paper, the wideband variation in the input impedance of a horizontal dipole over ground caused by the presence of a nearby underground anomaly (tunnel) is investigated via finite difference time-domain (FDTD) simulation. The correlation of the periodic variation in the dipole impedance difference to the location of the tunnel is demonstrated.

Silicone sealants were analyzed using dynamic shear rheometry (DSR) and numerical analysis to determine if a method could be developed that would provide the basis for a performance-based specification. The research used a three-phase approach including DSR analysis of aged and unaged sealants, numerical model development using the DSR data as input, and laboratory tension experiments for model verification. Results of the investigation indicated that the average material properties determined through DSR and laboratory tensile testing appeared to be representative of the “true” material properties for elongations of up to 25 percent. The results were less accurate for 50 percent elongation but still acceptable. The DSR testing could be related to field performance; however, conducting several tests on multiple samples to develop a discrete stress-relaxation spectrum for numerical analysis would not be feasible for most users. Instead, two test temperatures should be selected for DSR testing based upon the maximum and minimum in-use temperature the sealant would be exposed to for a given application.

In FY97, the U.S. Army Engineer Research and Development Center initiated a technology demonstration program to determine the feasibility of providing deployed troops with direct access to subject matter experts (SME). Direct access to the SME allows responses to engineering challenges beyond the in-theater capability to be provided without the time delays and costs associated with deploying the SME to the theater. The purpose of this report is to describe the various components of the fixed-site TeleEngineering communications system and to provide the step-by-step procedures required to set up and operate the system. Chapter 2 presents the components that comprise the system. Chapter 3 provides details on setting up the equipment and the interconnections between the individual components. The operation of the system (i.e., conducting a VTC and transferring data) is presented in Chapter 4; methods of receiving technical support are provided in Chapter 5. Appendix A provides a wiring diagram for the fixed-site system; Appendix B provides troubleshooting tips.

In FY97, the U.S. Army Engineer Research and Development Center ERDC) initiated a technology demonstration program to determine the feasibility of providing deployed troops direct access to subject matter experts (SME). Direct access to the SME would allow responses to engineering challenges beyond the in-theater capability to be provided without the time delays and costs associated with deploying the SME to the theater. Shortly after being established, the TeleEngineering Operations Center (TEOC) initiated an effort to develop a secure, deployable communications package and steps necessary to set up and operate the system.

In FY97, the U.S. Army Engineer Research and Development initiated a technology demonstration program to determine the feasibility of providing deployed troops with direct access to subject matter experts (SME). Direct Access to the SME allows responses to engineering challenges beyond the in-theater capability to be provided without the time delays and costs associated with deploying the SME to the theater. The purpose of this report is to describe the various components of the fixed-site TeleEngineering communications system and to provide the step-by-step procedures required to set up and operate the system. Chapter 2 presents the components that comprise the system. Chapter 3 provides details on setting up the equipment and the interconnections between the individual components. The operation of the system (i.e., conducting a VTC and transferring data) is presented in Chapter 4; methods of receiving technical support are provided in Chapter 5. Appendix A provides a wiring diagram for the fixed-site system.

A new slot/sealant configuration has been recommended for the installation of leaky coaxial cable sensor systems. This report documents the field performance of a trial installation at Westover Air Force Base, Massachusetts. Visual observations alter 2 years of service indicate that the new slot/sealant configuration is performing satisfactorily.

Pavement research and development in the military and civilian sectors have never been more necessary nor more visible than at the present time. There are a number of reasons that point to the urgent need to accelerate the research and development efforts. Some of the reasons that delineate this need include: the deterioration of our Nation's transportation infrastructure, increased congestion of our airports, proposed aircraft development of unprecedented size, depletion of paving materials and increased expense of existing pavement materials, and the increased dependence of our Nation's military on U.S. bases to project forces for regional conflicts. The objectives were to be achieved by evaluating the field performance of candidate materials through laboratory characterization and field test evaluations. Additional areas of interest included in the investigation were the environmental impact of using the new or waste materials in pavement systems, the effect of these materials on the performance of the pavement including the maintenance and life-cycle cost of the pavement, and potential constructibility problems associated with their use.

This report documents the Facilities Engineering Applications Program project 'Pavement Markings' which was conducted from FY88 to FY90. Two sites, Fort Bragg, NC, and Fort Lewis, WA, were selected for demonstrating techniques used to install various types of pavement markings. A brief description of the types of pavement markings and the different considerations used to select a marking type are presented. Pavement markings, Thermoplastic markings, Pavement tapes, Traffic markings, Raised reflective markings, Traffic paints

This report details equipment, personnel, and types of materials as well as the procedures used to demonstrate the application and inspection of field molded joint sealants to joints and cracks in portland cement and bituminous pavements. The description, applicability, benefits, limitations, costs, recommended uses, and location of demonstrations for pavement joint and crack sealing technologies are discussed.