|FHWA > Engineering > Pavements > Concrete > FHWA-HIF-09-005 > Chapter 1|
Advanced Concrete Pavement Technology (ACPT) Program-A Status Report on Available Products
Chapter 1: Introduction
Pavements are the critical elements of an efficient highway transportation system for moving people and goods. Without well-performing pavements, the transportation infrastructure cannot effectively function, road users suffer (in terms of increased costs, travel/commute time, and unsafe roads) and the overall economy suffers (in terms of higher costs for goods and commodities). Modern societies cannot function without mobility, and mobility requires well-performing pavements: it is as simple as that. Therefore, long-lasting pavements that are safer, smoother, and environmentally sensitive and can be cost-effectively constructed and maintained are an important part of the U.S. transportation system. In the United States, billions of dollars are spent every year to construct, maintain, preserve, and rehabilitate the Nation’s highway pavement infrastructure. The accumulated investment in our roadway pavements is in the trillions of dollars. This investment needs to be protected and managed efficiently so that generations of our citizens can continue to enjoy the benefits of one of the best highway systems in the world.
The Federal Highway Administration (FHWA), as part of its congressionally mandated role to improve mobility on our Nation’s highways through national leadership, innovation, and program delivery, has been actively involved in improving the technologies related to all types of pavements that are used on the federally funded National Highway System. FHWA currently conducts its Pavement Technology Program as authorized under the Safe, Accountable, Flexible, and Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). Within that program, FHWA’s Innovative Pavement Research and Deployment (IPRD) Program accounts for a significant portion of SAFETEA-LU funds; and, the deployment, delivery, and implementation of advanced concrete pavement technology (ACPT) products are key elements of FHWA’s IPRD program efforts to improve the long-term performance of portland cement concrete (PCC) pavements.
Since the late 1950s and early 1960s, when construction of the Interstate Highway System began, there have been significant developments in various aspects of concrete pavement technology. During the Interstate highway construction era, concrete pavements were designed to provide a low-maintenance service life of about 20 years, whereas now the current practice, as followed by most U.S. highway agencies, is to consider design life requirements of 40 to 50 years. While much progress has been made in the last few decades to improve the performance of concrete pavements and to reduce overall life cycle costs, many challenges remain, and new challenges surface that necessitate a strong commitment to a vigorous research and development program and a strong technology transfer program to improve concrete pavement technology. Some of the challenges are listed below:
FHWA has traditionally been committed to maintaining and funding a strong research and development program to improve concrete pavement performance. During the late 1990s, with funding support from the TEA-21 bill, FHWA began consolidating its overall concrete pavement research and development (R&D) program under the Concrete Pavement Technology Program (CPTP) umbrella in partnership with the State departments of transportation (DOTs), industry, American Association of State Highway and Transportation Officials (AASHTO), Transportation Research Board (TRB), and academia. More than 30 R&D and technology transfer implementation projects were funded under the CPTP covering a broad range of topics, from evaluations of pavement design and design features to assessment of materials, construction, and repair and rehabilitation activities. FHWA has also supported several other topic-specific programs related to alkali-silica reactivity (ASR), concrete overlays, continuously reinforced concrete pavements (CRCP), precast concrete pavements, and pavement surface characteristics (ride, safety, and noise). In addition, advanced research and technology transfer activities are also supported by State DOTs, academia, and industry. Recently, under the CPTP, the Concrete Pavement (CP) Road Map was developed and many of the research activities are now being coordinated under the umbrella of the CP Road Map, in partnership between FHWA, State DOTs, industry, and academia (Ferragut et al. 2005).
FHWA has initiated the ACPT Program to capture the best advanced technologies available or soon to be available for concrete pavements and deliver these technologies to highway agencies and the construction industry. The ACPT program has tremendous potential to build upon the successes of past concrete pavement technology programs to deliver implementable products that pavement engineers and managers can apply to design and construct more cost-effective, longer lasting, and environmentally sensitive concrete pavements, and to be able to rehabilitate concrete pavements more effectively by adhering to the philosophy of “Get in as soon as possible; do it right; get out as quickly as possible; and stay out as long as possible.” This report documents the availability of advanced concrete pavement technology products that show a high potential for improving the performance of concrete pavements, through improved design, material selection, construction practices, testing procedures, and repair/rehabilitation techniques. These technologies also include concrete overlays for rehabilitation of existing PCC and asphalt pavements.
The ACPT products for technology transfer, as documented in this report, are the result of research and development projects with one or more sponsors, either domestic or international. The primary sources of ACPT products include projects sponsored by FHWA, State highway agencies, industry, and academia. However, the results of concrete pavement research activities conducted in other countries, principally European countries, have been considered, as they can make a significant contribution to the full range of ACPT products available for deployment, delivery, and implementation in the United States.
Current State of Pavement Technology
Since the late 1950s, when the U.S. interstate highway construction program was initiated, significant progress has been made in advancing the state of practice and the state of knowledge related to both asphalt and concrete pavements. Pavements, in both urban and rural areas, are being designed for long life. For concrete pavements, the initial planned design life is typically 30 to 40 years. The advances in optimizing concrete pavement design features (use of stabilized bases, widened lanes, concrete shoulder, drainage, and doweled joints), availability of improved concrete-making materials, more efficient construction equipment, and better understood processes for achieving quality construction, are helping pave the way for constructing smoother, safer, sustainable, environmentally friendly, and longer lasting concrete pavements. While much progress has been made in concrete pavement technology, gaps do remain in achieving consistently what we know to be attainable.
A significant amount of effort and monies expended by U.S. highway agencies is directed at preservation, repair, and rehabilitation (PRR) of existing asphalt, concrete, and composite pavements. Pavements do deteriorate with time and traffic loadings and because of concrete material failures. Sound corrective measures performed in a timely manner can greatly extend the service life of existing pavements. The goal of the corrective measures is to extend the useful life of these pavements (structural capacity and functional characteristics) with the least life cycle costs and in a sustainable manner. Over the last two decades, there has been much progress in developing effective PRR techniques. However, many gaps remain, and many practices are not implemented consistently from one region to another. An important technical limitation is associated with our ability to rationally determine what treatments need to be performed at what stage in the pavement’s life and what are the consequences of delaying needed treatments. In today’s environment, where highway agency budgets cannot fully meet the needs for managing pavement assets, and with no lessening in traffic growth and public expectations, it is important that the limited funds available to maintain our highway systems be expended in an optimum manner. Furthermore, there is a greater demand to minimize the impacts of pavement rehabilitation activities on facility users.
There are many needs that are driving the push for advancing the technologies that provide smoother, safer, sustainable, environmentally friendly, and longer lasting concrete pavements:
The ACPT program is expected to help bridge the gap between current practices and user expectations of the level of service that pavements need to provide. As discussed in subsequent parts of this report, advances continue to be made in concrete pavement technologies. The promising technologies to be implemented under the ACPT Program will support the goals of FHWA and highway agencies for effective and responsible management of the Nation’s highway pavement infrastructure.