Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
4 The U.S. roadway infrastructure system that was built up during the past several decades is beginning to age, resulting in the need for renewal or repairs of significant portions of the network over the next few decades. Correspondingly, traffic volumes throughout the network have increased, resulting in the need for increased capacity. Increased traffic volumes also create challenges for performing renewal and repairs. Because of the importance of the roadway network to local and regional commerce and to the quality of life of residents and roadway users, any disruptions from construction activities can have negative economic and social impacts, particularly on roadways with few practical detour options or in urban areas with severe congestion. Highway agencies are regularly faced with having to minimize, mitigate, and manage these disruptions and keep the roadways operational while performing the various construction activities associated with their renewal, rehabilitation, or upgrading. The chal- lenges are particularly difficult for concrete pavements because of the time needed for curing and strength gain before permitting traffic back on to the roadway. Highway agencies across the United States are increasingly looking to implement policies, procedures, and practices to maintain a high level of construction quality while maintaining safe operations, reducing traffic impacts, and providing quick public access. Experience at a number of agencies has shown that the construction of concrete roads and concrete overlays and the repair and rehabilitation of concrete pavements on existing alignments can be effectively and safely performed under traffic conditions, while reducing disruption to the traveling public and to local residents and businesses. Vehicle delays, motorist safety, environmental impacts, and road-user satisfaction are generally considered when constructing and rehabilitating concrete pavements under traffic, and the devel- opment and implementation of effective maintenance of traffic (MOT) plans becomes essential. Advancements in materials, paving equipment, and placement techniques are also factors to be considered. Other considerations pertain to the communications among highway agencies, con- tractors, various stakeholders, the traveling public, and other agencies/organizations (e.g., law enforcement, media, local businesses) to help reduce disruptions and delays during the course of a concrete pavement construction or rehabilitation project and to project delivery and procure- ment methods. Over the past few decades, many projects have been constructed under varying levels of traf- fic with increased efficiencies and decreased disruption to traffic. Strategies have ranged from temporary closures to maintaining a high level of traffic volume adjacent to or through the project. These projects incorporated advancements and changes in project planning, project delivery, construction materials and processes, construction and MOT equipment, and project management. The purpose of this synthesis is to compile, review, and document these practices, strategies, and advancements that can be considered for the construction and rehabilitation of concrete pavements under traffic. C H A P T E R 1 Introduction
Introduction 5 For this synthesis, concrete pavement construction includes jointed plain concrete pavements (JPCPs), continuously reinforced concrete pavements (CRCPs), roller-compacted concrete (RCC) pavements, composite pavements (including a new asphalt surface over new concrete or two-lift concrete over concrete), and precast concrete pavements. They can be a complete recon- struction on an existing roadway alignment or the widening of an existing roadway. Major con- crete rehabilitation to increase structural capacity and service life of existing roadways includes bonded concrete overlays of existing concrete pavements, unbonded concrete overlays of exist- ing concrete pavements, and thin or ultrathin bonded concrete overlays of existing asphalt pave- ments. Rehabilitation of concrete pavements also includes activities to extend the service lives of pavements without increasing structural capacity. These include diamond grinding and groov- ing, slab stabilization, partial-depth repair, full-depth repair (including precast repair), load transfer restoration or dowel bar retrofit, crack stitching, and edge-drain retrofit. Three tasks were conducted for this synthesis: a literature review, an agency survey, and devel- opment of case examples. A literature review was conducted to document agency practices and to identify strategies relevant to construction and rehabilitation of concrete pavements under traffic. A survey questionnaire was created and distributed to highway transportation engineers across 52 transportation agencies [all 50 U.S. state highway agencies, the Illinois Tollway, and the District of Columbia Department of Transportation (DOT)] using a web-based survey tool with analytic capabilities. A total of 45 survey responses were received, which included responses from agencies indicating that they did not use, or rarely used, concrete pavements. Based on the responses received on the survey questionnaire, some agencies were selected to provide case examples illustrating a variety of projects with different situations and considerations. The information in this synthesis is presented in five chapters. Following this introductory chapter, considerations and strategies for construction and rehabilitation of concrete pavements under traffic are discussed in Chapter 2. The information presented in Chapter 2 is obtained from a review of current literature. The chapter includes a review of work zone management and issues to consider, followed by a review of considerations and strategies for the construction and rehabilitation of concrete pavements under traffic relevant to (1) MOT; (2) project planning and construction staging; (3) materials and design; (4) equipment and operations; (5) project management, delivery, procurement, and payment; and (6) communications and outreach. Chapter 2 concludes with a summary of considerations for concrete construction under traffic. The results of the agency survey are presented in Chapter 3. Following a review of the types of concrete pavement construction and rehabilitation practices at various highway agencies, the chapter presents agency practices and experiences pertaining to (1) MOT, (2) materials and design, (3) paving equipment and concrete placement, (4) paving operations, (5) project manage- ment, (6) project delivery, (7) project procurement, (8) payment methods, (9) project-related communications, (10) public outreach, and (11) motorist information. The chapter concludes with agency responses to reasons for modifying or not modifying standard practices for con- structing or rehabilitating concrete pavements under traffic conditions. Sixteen case examples of construction and rehabilitation of concrete pavements under traffic are presented in Chapter 4. These case examples encompass a wide variety of conditions, ranging from Interstate highways to city streets, from two-lane roadways with construction on one lane and traffic in the adjacent lane to multilane paving with full roadway closures, and from full reconstruction with widening to rehabilitation. The case examples include bonded overlays, unbonded overlays, precast pavements, and RCC pavements. The report is summarized in Chapter 5 with conclusions and suggestions for further research.