Color-Coded Map Overlay Augmentation for Unmanned Vehicle Sensor Management

Four color-coded overlays that augment a tactical map were evaluated as candidates for multi-unmanned vehicle (UV) sensor management by a single operator. Each overlay provided six levels of temporal information to indicate how long ago each map location had been viewed by a UV. Twelve participants completed 140 trials, each trial posing a question to be answered by retrieving spatial-temporal information from static map overlays. The accuracy of the participants’ answers significantly differed as a function of overlay type. Suggestions for overlay design and future research methodology are provided.

Structural Characterization of Fractured Portland Cement Concrete Pavements in Pennsylvania from Falling Weight Deflectometer Data

Hot mix asphalt (HMA) overlays on fractured Portland cement concrete (PCC) is a common rehabilitation alternative used for PCC pavements in Pennsylvania. Several fracture techniques including rubblization, crack and seat (C&S), and break and seat (B&S) have been used for decades to minimize reflective cracking by reducing the effective slab length and, with it, expansion/contraction movement. The design of this type of overlay requires knowledge of the structural capacity of the fractured PCC layer. The AASHTO 93 and Pavement ME design methods are used by the Pennsylvania Department of Transportation (DOT). These methods and the Pennsylvania DOT documentation recommend certain values to characterize the structural capacity of the fractured PCC. However, the guidance envisaged the selection of these values provided by these design methods and the Pennsylvania DOT documentation is limited. The objective of this study is to determine realistic Pennsylvania-specific elastic modulus (EPCC) values and layer coefficients (LC) to characterize the in situ behavior of fractured PCC layer for jointed reinforced concrete pavements (JRCP) and jointed plain concrete pavements (JPCP). To obtain these structural properties, 11 different rehabilitation projects located in Pennsylvania were analyzed using falling weight deflectometer (FWD) data, backcalculation programs, and statistical methods. Based on this analysis, the recommended values of EPCC and LC for C&S overlay design are 360 ksi (kips per square inch) and 0.32, respectively. In the case of B&S overlay design, these values correspond to 400 ksi and 0.34, respectively. The variability of the slab fracturing process and the reduction of the structural capacity caused by fracturing were also analyzed in this investigation.

Relationship between Backcalculated and Estimated Asphalt Concrete Dynamic Modulus with Respect to Falling Weight Deflectometer Load and Temperature

There are several methods for determining the stiffness of asphalt concrete in an existing pavement. The three primary methods are: dynamic modulus testing in the laboratory, predictive equations, and falling weight deflectometer (FWD) testing. Asphalt over asphalt (AC/AC) overlay design procedures allow the use of multiple methods to characterize fatigue damage in the existing asphalt concrete. Therefore, understanding the difference between these methods is critical for AC/AC overlay design. The differences between the methods for determining asphalt concrete stiffness and how these differences are related to FWD load magnitude and asphalt temperature are examined. Data from the Federal Highway Administration’s Long-Term Pavement Performance Program (LTPP) are used in this investigation. It is found that the stiffness determined through FWD testing and backcalculation is generally less than that estimated using the Witczak predictive equation and binder aging models. Furthermore, it is found that both FWD load magnitude and asphalt temperature have a significant effect on the difference between backcalculated and estimated stiffness of asphalt concrete. Backcalculated stiffness increases relative to estimated stiffness as FWD load and temperature increase. These effects must be considered when multiple methods of determining asphalt concrete stiffness are used interchangeably for overlay design.

Principles, Procedures and Policies Adopted in Improvement and Widening of Roads (Sh-88)

Road widening is the solution for the problem of traffic density and road accidents, transportation infrastructure is the ever green problem facing all over the world, as day by day with the growth of economic status the people are switched to use four wheelers from two wheeler vehicles, the roads at present are mean for the capacity of the present situation, as the traffic density increases the improvements in road infrastructure and widening of roads are required. We concentrated on the different road widening problems and solutions carried out and mainly focused on the Mysore Bantwal Road (SH-88). The need of this research is to design Road transport model to ensure safe and effective moment of traffic. We even discussed different principles, policies and procedures of the design standards and guidelines. The major aim is to reduce economic losses and to improve capabilities for overlay design that are provided to meet today’s highway traffic needs. Finally we used IIT PAVE software for calculating fatigue and rutting performance criteria.

Pavement Overlay Design using Falling Weight Deflectometer

Pavement evaluation is a technique of assessing the condition of a pavement, both structurally and surface characteristics. Pavements which have been subjected to traffic, deform elastically under load which depends on type subgrade soil and its compaction level, pavement thickness and its composition, drainage conditions, pavement surface temperature and wheel load. There are number of different types of pavement deflection testing equipment which are being used all over the world. The most common types are Benkelman Beam Deflection (BBD), Falling Weight Deflectometer (FWD) and Dynamic Cone Penetrometer. BBD test widely used method in which rebound deflection is measured on static loading and there by evaluating strength of the pavement. However with limitations and practical difficulties of BBD, FWD was chosen for the study. The deflections of the pavement are recorded due to the dynamic loading and studied for further strength determination. A 4-lane National Highway has been selected and tested for residual strength and it is designed for overlay as per IRC:115-2014 & IRC:37-2012 using FWD equipment and with the assistance of KGPBACK and IIT PAVE software’s. An overlay of 50 mm on one direction and 100 mm on opposite direction was recommended to meet the functional and structural requirement respectively.