Test Deck Research Articles

Modeling of Restriping of Waterborne Paints Using Transverse Test Deck Data in Hot and Humid Climate

The National Transportation Product Evaluation Program (NTPEP) database is a promising tool for U.S. state agencies to evaluate the performance of waterborne paint pavement markings. Out of the total 50 U.S. states, 29 states (57%) utilize the NTPEP data to assess the performance of waterborne paints to be included in the approved materials list. Yet, this dataset is based on transverse retroreflectivity (RL) measurements, which are significantly different from the longitudinal RL measurements in real-world conditions. As such, the key objective of this study was to develop a methodology that converts the transverse RL measurements of waterborne paints to the corresponding longitudinal measurements in hot and humid climate. This approach could be used by transportation agencies to predict the service life of their waterborne paints and make reliable restriping decisions. To achieve this objective, three road sections were selected in Louisiana, U.S., and four different waterborne paints were installed in the transverse and longitudinal directions. These road sections consisted of seven subsections with varying traffic levels and pavement surface types. The data collected included durability readings and longitudinal and transverse RL measurements at five time periods between October 2020 and April 2022. Based on the collected data, two non-linear regression models (for asphalt and concrete surfaces) were developed, with reasonable accuracy, to predict the longitudinal RL of waterborne paints based on the corresponding transverse RL. The predicted longitudinal RL could then be used to determine the expected service life of waterborne paints and make reliable restriping decisions.

Characterization of glass beads by image methods for pavement marking retroreflectivity

Road safety is a worldwide concern. Traffic injuries are the main cause of death for children and young people. One alternative to improve traffic safety is the enhancement of pavement markings visibility. Pavement marking efficiency depends on day and night visibility. Nighttime visibility (retroreflectivity) occurs due to the presence of glass beads. This paper compares the performance of two glass beads: G1 – Brazilian glass bead produced with recycled glass; and G2 – imported glass bead produced with new material. The research evaluated the retroreflectivity decrease of a test deck using two water-based paints from different manufacturers. The glass beads characterization process used the Computerized Optical Equipment (COE), CamSizer, and the Aggregate Image Measurement System (AIMS) to evaluate the shape, size, and gradation. Results indicated different retroreflectivity decrease trends for pavement markings with distinct glass beads, which could be associated with their shape characteristics and grain size distribution. The glass beads G1 presented the worst shape properties which lead to the poorest retroreflectivity at the test site. Thus, image characterization is helpful in estimating markings retroreflectivity prior to its application. Therefore, G1 cannot be used to substitute G2, regarding the retroreflectivity requirements in Brazil.

Vote Simulation Scripts and Test Deck Generators: Patents and User's Manuals May Play A Role in the 2020 Election Litigation

Introduction As judges seek to separate the fantastical from the plausible in election suits and related defamation cases, patents and user’s manuals may be a strong tool. When characterized as public records, business records, or opposing party statements, these documents may avoid many of the admissibility challenges that have plagued election cases. The documents also provide a level of neutrality and reliability that affidavits and expert witnesses do not—as it is what the voting equipment company claims about its own software, these documents serve as a mutually agreeable baseline for the equipment capability. The especially partisan nature of election contests makes this a unique virtue of the documents. As such, parties in ongoing and future cases should not overlook them in preparing for litigation. Background and Summary The question whether election machines can plausibly be electronically manipulated was once a less exceptional view in academia and the mainstream media. After widespread concern of Russian interference in the 2016 Election and bipartisan interest in securing future contests, significant private and governmental resources were aimed at investigating our country’s voting infrastructure. In 2018, the National Academy of Sciences, Engineering, and Medicine commissioned a study on how our election infrastructure can be strengthened. At DEF CON in 2019, the conference attendees famously hacked every single machine present “in ways that could alter stored vote tallies, change ballots displayed to voters, or alter the internal software that controls the machines.” As recent as January 2020, Congress called in the three largest providers of equipment for testimony. In an article on the hearing, NBC wrote “The three companies . . . are almost entirely unregulated. But in recent years, policymakers and election advocates have begun to question who owns the companies, how they make their machines and whether they could be susceptible to remote hacking.” Many in academia predicted that these claims and concerns would continue beyond the 2020 Election. They were correct. This has led to a slew of lawsuits and some high-profile defamation cases. Central to most of them is the question whether vote manipulation using an algorithm or vote simulation script is sufficiently plausible to adjudicate. Patents and user’s manuals often describe these functions and may be useful tools to judges seeking to answer this question. Two documents, a patent and a user’s manual, in particular will be used as a case study. Beginning with the patent, these documents’ usefulness and admissibility are each described in turn.

Experimental feasibility study of a new attached hydronic loop design for geothermal heating of bridge decks

Geothermally heating of bridges is a green and sustainable alternative to deicing chemicals, which are energy-intensive, corrosive to the bridges, and dangerous to the environment. Geothermal bridges harness shallow earth geothermal energy, a readily available all-year-round renewable energy source. However, the existing geothermal heated bridge technology was developed based on embedded hydronic loops, which can be only deployed during the construction of new bridges. As there are more existing bridges in the critical need of deicing, a new attached hydronic loop design was developed in this study for geothermal heating of existing bridges. The hydronic loops are attached to the bottom of a bridge deck and are encapsulated inside an insulation material geofoam. The developed hydronic loop was tested on a lab-scale concrete deck with supplied warm water to evaluate its feasibility for field application. This heated deck system was fabricated and instrumented for the heating performance tests in an environmental chamber. It was first tested under various room temperatures higher than 4.4 °C, the lowest temperature permitted by the environmental chamber. Based on the test results, an empirical prediction equation is presented to estimate deck temperature at given ambient and supplied heating fluid temperatures. The applicability of this equation to freezing temperature was validated in localized freezing tests by placing a cooling box on the test deck. All test results show that this heated bridge deck allows efficient heat transfer, approximately 60% of the supplied heat, to the bridge deck surface. The supplied heat flux to the deck surface ranges from 120 to 270 W/m2 depending on the ambient and heating fluid temperature, which is comparable to the embedded hydronic system. The new hydronic loop design is feasible to be implemented on the existing bridges for deicing and snow removal.

Evaluation of Audible Lane Departure Warning Treatments on Seal Coats

To help reduce single vehicle run-off-road and two-lane two-way crossover crashes, Texas Department of Transportation (TxDOT), United States, has implemented various audible lane departure warning systems on seal coat road surfaces. This 20-month research project explored the effectiveness of these treatments using interior noise and vibration performance metrics and provided recommendations on implementation of these types of treatments. The researchers conducted performance evaluations at 24 unique field sites that had 51 treatments, and at a test deck that had 12 different variations of audible markings. The field sites consisted of varying designs and spacing of audible markings, varying spacing of rumble bars, and milled rumble strips. Researchers found that treatment effectiveness varies with vehicle type and vehicle speed. Traveling at higher speeds and in a vehicle with a stiffer suspension results in higher noise and vibration levels. The specific treatment design also impacts the performance. Treatments with closer spacing, longer bumps, and higher profiles produced higher noise and vibration levels. Certain alternative treatments were able to produce noise and vibration levels that approached levels of typical milled rumble strips. In areas where milled rumble strips cannot be used, these alternative treatments are viable options.

Investigation of the behaviour of SCC bridge deck slabs reinforced with BFRP bars under concentrated loads

Self-compacting concrete (SCC) with high-volume industrial wastes, such as fly-ash, reinforced with fibre-reinforced polymer (FRP) bars is anticipated to address the concerns on the usage of traditional reinforced concrete structures, such as corrosion of internal steel reinforcement, costly repair and development to low-carbon footprint infrastructures. However, few studies deal with the combined use of these sustainable materials and this has been the key motivation of this undertaking. This paper presents an experimental study investigating the behaviour of SCC bridge deck slabs reinforced with basalt fibre reinforced polymer (BFRP) bars, which is aimed at extending previous research using the combination of BFRP reinforcement and SCC in deck slabs of a real bridge named as Thompson Bridge. A total of six half-scale deck slabs were conducted and tested up to failure over single concentrated loads acting on the centre of each slab. The observed model failure for all the test deck slabs was punching failure. The punching capacity of the test deck slabs was validated with the predicted capacity from the existing theoretical methods in the literatures. The experimental and analytical results are discussed and conclusions on the behaviour of the BFRP reinforced SCC deck slabs are presented.

Investigation of the Ultimate Capacity of NSM FRP-Strengthened Concrete Bridge Deck Slabs

The use of near-surface-mounted (NSM) fibre-reinforced polymer (FRP) is a promising technology for increasing ultimate strength of concrete structures. However, the application of this strengthening method in concrete deck slabs is rather limited. This paper reveals a study of the ultimate capacity of concrete bridge deck slabs strengthened with NSM FRP rods. An experimental investigation on concrete deck specimens was carried out to identify the effect of NSM strengthening method on the failure mode and loading carrying capacity. The test results show that this strengthening procedure can increase the effective punching depth and enhance the punching capacity of concrete deck slabs. Interestingly, the NSM FRP strengthening strategy combined with arching action has a cumulative beneficial effect on the ultimate strength. Additionally, the ultimate strength of the test deck slabs was predicted by theoretical models reported in some reported studies. It is found that those methods yield highly conservative predictions. Subsequently, a modified theoretical model that takes into account of arching action is proposed. By validating the predicted strengths with the test results, the proposed method accurately predicted the ultimate strength of bridge deck slabs strengthened using NSM FRP.

Laboratory Investigation of Fire Transfer from Exterior Wood Decks to Buildings in the Wildland–Urban Interface

In the wildland-urban interface, wood decks are a target for wildfire and may be ignited by firebrands or flaming debris. Wood decks also present a potential source for ignition of structures in the wildland-urban interface. However, their role in ignition of the adjacent structure is unclear and current regulation is based in part on anecdotal evidence. This paper examines the results of a set of preliminary laboratory experiments used to determine how experimental variables affect the thermal exposure from a burning wood deck to an attached structure. The experimental setup consists of a test deck of 609 mm by 711 mm (24 inches by 28 inches) on a stand with an attached back wall equipped with two heat flux sensors and twelve thermocouples. Two ignition sources were considered: a below deck flame test using a propane burner and an above deck test using a Class A burning brand. The initial tests study the effect of wind and burner size and were all conducted on redwood decking. The experimental data from these tests showed that wind speeds of 2.9 m/s (6.5 mph) and 5.4 m/s (12 mph) had the highest temperature and heat flux on the wall. These winds were then further tested on three different species; redwood and inert deck boards. The test methods developed herein and the data obtained can be used to gain insight into how a burning wood deck contributes to structural ignition.

Predicting Pavement Marking Service Life with Transverse Test Deck Data

Pavement marking test decks are an effective way to evaluate the quality of marking in the field. Transverse test decks provide accelerated wear on markings in the wheelpath area and can provide a side-by-side comparison of different pavement marking materials. The drawback is that the relationship between transverse and long-line pavement marking test decks is relatively unknown. This study was developed to provide better understanding of the relationship between the accelerated wear area on a transverse marking and how it relates to typical wear on a longitudinal marking. The objective of the study was to develop a model for predicting long-line pavement marking retroreflectivity values from transverse pavement marking test deck data. These models and associated parameters can be used to estimate the retroreflectivity of an edge line marking or the amount of time it will take for the edge line marking to reach a given retroreflectivity level. The user needs only the transverse retroreflectivity readings and an initial or assumed initial edge line retroreflectivity value.

Assessment of Presence Conditions of Pavement Markings with Image Processing

This paper presents a systematic approach that can automatically determine the presence conditions of pavement markings from marking images developed with digital image processing techniques. These techniques are used to correct geometric deformity, detect colors of pavement markings, segment images, enhance images, detect edge lines of pavement markings, and recognize the features of pavement markings appearing in the photographs. The performance of this system was investigated with the photograph data sets provided by the National Transportation Product Evaluation Program Mississippi test deck. The empirical results (when compared with those from the manual method and expert observations) show that this method produced accurate and reliable results. The techniques in this study can be used to develop an automated system for accurate and speedy assessments of pavement marking conditions and might help agencies make a better decision in the maintenance of pavement markings.

Comparison of Designs of Field Test Decks for Pavement Marking Materials

Historically, pavement marking materials (PMMs) have been prequalified or selected mainly on the basis of product specifications and lab testing, which do not always correlate well with the field performance of the products. Although different configurations of field test decks exist for assessing the performance of markings, no consensus exists on the optimal design. This study evaluated test deck designs for PMMs on the basis of field performance and focused on a comparison of transverse line and long line design. Field decks were designed incorporating regular long lines and long lines in the travel lane together with transverse stripes for accelerated testing, and several installation procedures were taken into consideration. Three test sites in Texas were used for data collection and analysis. The relationships between transverse and longitudinal test decks were evaluated with correlation analyses of retroreflectivity values. The results indicated that the points on transverse lines had high correlation with the corresponding five or seven longitudinal long lines in the travel lane when the retroreflectivity values of all products on a test deck were averaged. For individual products, the correlations between transverse line locations and corresponding long lines in the travel lane were not consistently high for all PMMs.

Methodologies to Predict Service Lives of Pavement Marking Materials

This study focuses on developing methodologies to predict the service life of a pavement marking material based on its retroreflectivity. Data from the 2002 National Transportation Product Evaluation Program (NTPEP) pavement marking material test deck in Mississippi are used for model development and model validation. The smoothing spline method and time series modeling are applied to estimate the service lives of different types of materials based on the assumption of a required minimum retroreflectivity value. The same models can also predict the retroreflectivity values at future times for a pavement marking product based on its retroreflectivity values in the past. The validation of the models shows satisfactory accuracy. As demonstrated in a case study, the predicted service lives of the marking materials can be used in life-cycle cost comparisons for selecting pavement marking material.

Nighttime Visibility of Prototype Work Zone Markings under Dry, Wet-Recovery, and Rain Conditions

This paper presents the findings of a dynamic pavement marking visibility study conducted as part of the FHWA Highways for LIFE Technology Partnerships Program Temporary Wet-Weather Pavement Markings for Work Zones project. Three prototype optics-on-paint marking systems employing high refractive index dual-optics drop-on elements were evaluated at night under dry, wet-recovery (immediately after rainfall), and rain conditions. These three prototypes were chosen based on their durability from an initial pool of 22 experimental systems evaluated in a test deck. This dual-optic system was designed to provide good visibility in both dry and wet weather conditions. Two commercially available marking systems were also evaluated as industry benchmarks (one glass beads-on-paint system, one wet-reflective removable tape). Thirty participants driving through simulated work zones on a closed course viewed all of the marking types at night under all three weather conditions. Each driver's task was to identify the direction of work zone lane shift tapers delineated by the markings. In wet recovery, all three prototype marking systems and the wet-reflective tape sustained 60% to 80% of their dry average detection distances, and in rain, they sustained 50% to 70% of their dry average detection distances. In contrast, the average wet-recovery and rain detection distances for the conventional glass beads-on-paint benchmark system dropped to 28% and 17% of the dry detection distance, respectively. In addition, participants failed to detect the conventional glass beads-on-paint benchmark system in nearly half of the observations in the rain condition.

Exploratory Analysis of Accelerated Wear Testing to Evaluate Performance of Pavement Markings

Wear testing of pavement markings in the United States is commonly performed by AASHTO's National Transportation Product Evaluation Program. The pavement markings evaluated in this program are applied in a transverse manner along existing roadways, and a variety of objective measures are collected over a 2-year period. This paper reports the findings from an exploratory study on using the Model Mobile Load Simulator, third scale (MMLS3), to evaluate pavement marking performance along transverse test sections. Accelerated trafficking on wet and dry pavement surfaces was applied on sections of markings consisting of various waterborne paint products, marking thicknesses, and bead types and densities. Pavement marking retroreflectivity measurements were recorded at various stages of MMLS3 trafficking and compared with measurements of a test deck consisting of the same pavement markings subjected to live traffic. The findings suggest that the MMLS3 can consistently replicate the degradation pattern of the various pavement markings with regard to loss of retroreflectivity as a function of traffic passages. Performance varied among the various types of markings, with higher retroreflectivity observed for thicker markings with higher bead densities. Trafficking on wet pavement surfaces accelerated the degradation of the markings’ retroreflectivity.

Pavement Marking Retroreflectivity Inspection Data

Quantifiable life-cycle models of the service life of pavement markings are essential for a cost-efficient pavement marking management system. A study was conducted to develop an analysis procedure for typical pavement marking retroreflectivity inspection data. Retroreflectivity data collected by the National Transportation Product Evaluation Program on water-based paints in 2002 on a Pennsylvania test deck were used. Those data were considered interval-level duration data, and a Weibull analysis was performed. A Weibull analysis is a typical method in reliability engineering in which Weibull scale and shape parameters are estimated from failure data for making objective maintenance decisions. Results of the Weibull analysis indicated that the water-based paints had shape and scale parameters of 1.42 (±0.05), and 601.67 (±17.73) days, respectively, for skip line areas and 2.38 (±0.08) and 227.41 (±4.48) days, respectively, for left wheelpath areas. It was also determined that the probability of 2-year water-based paints lasting above 100 mcd/m2/lx varied from 0% to 27%. The lower limit corresponds to the left wheelpath, and the upper limit corresponds to the skip line area. The left wheelpath markings failed to stay above 100 mcd/m2/lx after approximately a year, while skip line markings could maintain 100 mcd/m2/lx ratings or higher for more than 1,000 days. White markings were found to last longer than yellow markings for the same exposure. This study used data from a single site in Pennsylvania. A multisite analysis accounting for time and space variations is recommended before adopting this method for minimum pavement marking retroreflectivity standard assessment.

Wind Uplift Model for Asphalt Shingles

Current standard test methods of ASTM and Underwriter's Laboratories for wind resistance of shingles subject a small test deck of shingles, that have been sealed under heated conditions, to a fan-induced airstream impinging at a continuous velocity of 97 km/h (60 mph) for 2 h. (ASTM D3161 and UL 997). Although these standard test methods have served a useful purpose in the past, it is generally accepted today that they are deficient in a number of respects. These deficiencies include the test deck not containing any protrusions or valleys, the shingles being sealed under “ideal” conditions, and turbulence of the impinging air stream not being taken into account. In order to improve shingle performance, a wind uplift prediction model was needed. A research program was initiated by ARMA to understand, quantitatively, the uplift mechanism and to develop a prediction methodology suitable for product development. This paper describes the research leading to a quantitative uplift model and presents the results ...

Abscissae and weights for the Gauss-Hermite quadrature formula

Title of program: GAUSSH Catalogue number: ABBL Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: FACOM M-780/20; Installation: Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812, Japan Operating system: IV/F4 Programming language used: FORTRAN 77 High speed storage required: 264 Kbytes No. of bits in a byte: 8 Other peripherals used: card reader, line printer No. of cards in combined program and test deck: 261 Card punching code: EBCDIC

Subroutines for integration of systems of first order ODE's

Title of program: RKPC Catalogue number: ABBH Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: IBM 3083J24; Installation: University of the Witwatersrand Computer Centre Operating system: VM/SP HPO 4.2 Programming language used: FORTRAN VS LEVEL 1.4.1, LANGLVL (77) High speed storage required: 20272 bytes for OPT(0) compile No. of bits in a byte: 8 Peripherals used: card reader, line printer No. of cards in combined program and test deck: 617 Nature of the problem Numerical integration of the vector equation d y/d x = f( x, y). Method of solution Application of second to sixth order, fixed step, Runge-Kutta or predictor-corrector integration formulae. Restrictions on the complexity of the problem Vector dimension set for 20 components. Typical running times Dependent on required range and accuracy: for the test cases it is in the range 0.14 to 0.18 s.

Program “color” for computing the group-theoretic weight of Feynman diagrams in non-Abelian gauge theories

Title of program: COLOR Catalogue number: AAXC Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: IBM 360/370 Operating system: OS, VM Programming language used: REDUCE [1] High-speed storage required: depends on the problem; minimum about 400 Kbytes Number of bits in word: 32 Number of lines in combined program and test deck: 200

Subroutines for convolution sums of Chebyshev and Fourier series

Title of program: CCFS Catalogue number: ABBO Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland (see application form in this issue) Computer: IBM 3083J24; Installation: University of the Witwatersrand Computer Centre Operating system: VM/SP HPO 4.2 Programming language used: FORTRAN VS LEVEL 1.4.1, LANGLVL (77) High speed storage required: 27412 bytes for OPT (0) compile No. of bits in a byte: 8 Peripherals used: card reader, line printer No. of cards in combined program and test deck: 682 Nature of the problem Numerical calculation of the coefficients for a single series obtained as the product of two series. Method of solution Application of standard results for Chebyshev polynomials and Fourier series. Restrictions on the complexity of the problem Length of the series is not limited in the subroutine package but is limited to 41 terms in the main driver, I/O and test programs. Typical running times Dependent on required range and accuracy: for the test cases it is 0.15 s.