This workshop presents state-of-the-art pavement maintenance techniques, materials, and construction practices for asphalt and concrete pavements.
Road users view pavement performance from a functional perspective. Their opinion of performance is greatly influenced by ride quality, noise level and aesthetics. Pavement engineers on the other hand have a tendency to rate pavement performance by the severity and extent of distress or deterioration observed over time. This presentation will focus on identifying causes of pavement deterioration and the rate of development of pavement distresses with the goal of better understanding the appropriate timing of maintenance activities and solutions.
Crack sealing and crack filling are the most common pavement maintenance treatments because of their ability to keep water from penetrating into the cracks. Most agencies adopt these treatments not only because it is less expensive than other maintenance activates but also for ease of application.
Cracks can either be filled or sealed by hot-poured materials. Crack filling is defined as applying sealant into a cleaned crack. For crack sealing, a reservoir is made by cutting the pavement prior to the sealant application. Providing a reservoir will result in better adhesion to the crack walls and allow more sealant mass which will create a better depth to width ratio for movement.
Most studies show that crack sealing will last longer and be more effective at reduction of water penetration than crack filling. However, many agencies prefer to fill cracks rather than seal them because of faster installations, less labor and material or lack of proper guidelines. Although crack sealing preforms better, it is not necessarily more cost effective than crack filling. Based on site characteristics, crack filling can also show good performance and be the right choice for crack treatment. These characteristics include crack spacing, ambient and pavement temperature, temperature gradient between day and night, temperature difference between summer and winter, type of crack, the crack deterioration level and its initial condition, crack movement and overlay type.
There are other key factors for a good performance of crack sealing and filling. Each method needs attention during the installation. Selecting the right material is another critical aspect to have a good performance.
This presentation will discuss how to the right crack treatment option and why, selecting the proper material and the proper techniques for each treatment.
Over the course of their service life, concrete pavements undergo significant traffic and climatic loads leading to a gradual accumulation of damage. This accumulation of damage and distress comes from the effects of changing weather conditions (temperature and moisture) and continuous vehicular traffic. Repeated environmental and traffic loading leads to cracking and spalling of the concrete at the joint edges.
States in the northern portion of the United States and the provinces of Canada have climates that fluctuate greatly in temperature throughout the seasons. Greater temperature differentials cause greater deflections in rigid pavements which lead to more prevalent spalling and a larger need for partial depth repair (PDR).
Many state’s Department of Transportations (DOTs) utilize PDR as routine practice to maintain the concrete pavements. For example Minnesota, North Dakota, South Dakota, Idaho, Montana, Washington and Wisconsin DOTs use this method. There is need for enhanced acceptance criteria of rapid set cementitious materials for use in partial depth repair. The purpose of this presentation is to report laboratory characterization of a number of rapid patching mixtures and to propose a laboratory testing based product acceptance specifications for rigid pavement patching materials.
This presentation summarizes 31 NCC State Members use of and expected life for the following concrete maintenance/ rehabilitation techniques: Full Depth Repairs, Partial Depth Repairs, Dowel Bar Retrofits and Diamond Grinding. Also discussed are pavement smoothness incentives and slurry management practices
Although potholes are one of the most severe pavement distresses and often expensive to repair, few models have been developed to predict their formation in order to proactively address them. Various factors, internal and external, result in the initiation and progression of potholes. Internal variables include pavement structure and design, construction, and materials, while external factors include traffic loads, weather conditions and frequency of maintenance activities. The large number of factors, as well as the variation in work and material quality during construction and maintenance activities, make the prediction of potholes more difficult than other pavement distresses types. In view of the above, this research attempts to model the probability of pothole formation using a wide range of internal and external factors, rather than directly including material properties or pavement structure behavior in the model, in order to achieve practically applicable results.
A sample of 25 pavement segments located in four Midwestern states in the United States was examined. Data for existing potholes, frequency of maintenance activities, age, traffic loads, weather records and pavement structure were collected for these segments for the years 1996 through 2012. A binary probit model was estimated to investigate the likelihood of pothole formation. Estimation results indicate a combination of factors that are most likely to result in pothole formation. Highway agencies can use this information to select the best pavement structural design under specific anticipated traffic loads and weather conditions in order to reduce the probability of pothole formation.
Hot-applied mastics have been utilized effectively for pavement repair in the United States for at least 20 years. The hot-applied mastics consist of a highly polymer modified binder and specially selected aggregates. The combination of flexibility and stability a proper formulation produces allows these materials to function in distresses larger than cracks but smaller than pavement replacement. These distresses include deteriorated longitudinal paving joints, wide cracks, edge joints, localized alligatored areas, micro trenching and depressions such as depressed cracks and cupping.
As the technology around us including both with pavements and in other areas grows, the distresses this causes to pavements also grows. These new technologies include new safety features such as rumble strips and recessed retroreflective markers. Fiber optic cable channels are another area where pavement is being cut. The distresses this causes include damage to the rubble strips themselves, plunge cuts for recessed markers and cuts for the fiber optic cables.
Agencies and users are finding that the adhesion, stability, flexibility and ease of use of hot-applied patching mastics can repair a wide variety of pavement distresses. This presentation discusses the current uses and applications as described above of hot-applied mastics as well as discussing the new repair uses for these hot-applied patching mastics.