Cross-cutting Issues

Bridge and pavement deterioration due to increased truck loading has been a major problem to U.S. road systems. The purpose of this study was to examine this widespread pavement and bridge degradation issue. This paper also discusses possible technical and policy remedies to finance transportation infrastructure maintenance to mitigate the damage from these overloaded vehicles. This study found a lack of quantitative data regarding the actual damage to bridges and pavements due to increased truck loadings, necessitating further studies. Availability of quantitative data on actual damage to bridges and pavements due to increased truck loadings will support the development of objective policy and technical solutions.

Authors: Kakan C. Dey, Weichiang Pang, Mashrur (Ronnie) Chowdhury

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

This paper presents an iron wire trigger mechanism that will be used for a new generation of low-cost corrosion sensors that are wireless and do not require batteries or any other external power sources. The corrosion rates for thin sensor wires, 0.065 to 0.25 mm in diameter, were investigated in sodium chloride solutions and compared with the mass loss from steel coupons under similar conditions. The 0.125 and 0.065 mm wires were embedded in concrete and subjected to accelerated corrosion testing. These wires behaved similarly to mild reinforcing steel used in concrete structures and trigger at predictable chloride levels and are suitable for uses as trigger for corrosion. Prototype sensors, constructed using commercial radio-frequency identification tags with a section of the antenna replaced by a wire trigger, embedded in concrete and stopped responding at reproducible chloride concentrations. These results demonstrate the methodology to create successful radio-frequency identification based corrosion sensors.

Authors: Nicholas Materer, Paul Field, Nicholas Ley, Ahmad Razzaghi, Dane Scott, Tyler Ley, Allen Apblett

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

We outline an affordable system that continuously monitors the road network for surface
damage like potholes and cracks. The system consists of a structured light sensor and a
camera mounted on vehicles that travel the roads on a regular basis. It makes use of sensors
and equipment already present on the vehicle, like GPS on transit buses. The data is collected
from many vehicles, aggregated and analyzed at a central location and the assessment results
are displayed interactively to facilitate road maintenance operations. We describe in detail the
key sensor, the data it collects and the algorithm to detect cracks and potholes.

Author: Christoph Mertz

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Title: Identification of Causal Factors of Bridge Failure through Fault-Tree Analysis and Intelligent Sensor Solutions

Bridges are the lifelines of the United States surface transportation network and support the growth of our nation’s economy; however, rapid economic growth over that past few decades has stretched the design capacity of many bridges in the United States. In recent years, there have been several incidents of bridge collapse, which calls for an urgent need to develop a systematic method of assessing the failure risks and identifying the initiating events that can lead to a bridge collapse. This paper presents a process of bridge failure risk analysis through fault-tree modeling and identifies potential structural health monitoring (SHM)-based intelligent sensors as countermeasures. This research concluded that integrating SHM sensors with Intelligent Transportation Systems (ITS) is a cost-effective way to monitor nation’s transportation infrastructure for both structural and operational problems.

Authors: Caitlyn Davis-McDaniel, Mashrur Chowdhury, Wei Chiang Pang

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida

Remote sensing of the pre-existing and the active cracks in accessible as well as in not easily
accessible concrete structural components under variable stress is critical to improve the
procedures for their maintenance and thus to increase the service life of the structure. Initiation of cracks in asset components can occur due to load, weather (e.g. freezing and thawing), alkaline aggregate reaction, debonding as well as rebar corrosion in reinforced concrete, cable wire breaks, girder damages etc. An active combination of these factors accelerates the asset deterioration process, dynamics of its growth and untimely failure. Cracks result from weakening of the interfacial bonds and/or stressed initiated fatigue. This paper discusses the success of the wireless broadband technology to monitor health of the transportation assets in a near real time from a remote location using the non-destructive technology (NDT) of acoustic emission (AE). A study, that includes both the stay cable and its concrete support structure on the Varina-Enon Bridge near Richmond, Virginia, has been considered as a test case. It aims to: (i) locate the areas of active microcracks; (ii) investigate the dynamics of microcrack formation, (iii) determine if a wire broke and; (iv) transfer the time stamped digitized AE signals on a near realtime basis to a remote location for efficient analysis and information dissemination. 16 AE sensors and a broadband wireless installed DAQ system was used for data acquisition and its real time transfer for analysis on windows XP platform at a remote location.

Author: Devandra S. Parmar

Presented at the 18th World Congress on ITS, October 2011, Orlando, Florida