Proceedings of the International Conference on Concrete Pavements
Welcome to the International Society for Concrete Pavements' Open Journal System (OJS), including the Proceedings of the International Conference on Concrete Pavements! The journey of these conferences began with the First International Conference on Concrete Pavement Design, held at Purdue University in West Lafayette, Indiana, USA on February 15-17, 1977, followed by the Second Conference in Indianapolis, Indiana on April 14-16, 1981. Both events were expertly planned and organized by Dr. Eldon J. Yoder, Professor of Civil Engineering at Purdue University. Dr. Yoder's lasting influence was commemorated with the Third International Conference, dedicated to his memory and contributions to the field, held at Purdue University on April 23-25, 1985. Subsequent conferences continued at Purdue University, with the Fourth and Fifth held in 1989 and 1993, respectively, and the Sixth in nearby Indianapolis, Indiana in 1997. In 1999, the International Society for Concrete Pavements was established to continue Purdue University's legacy of advancing technology in this field. For nearly three decades, the ISCP has hosted the International Conference on Concrete Pavements every four years, at locations in the USA and Canada, with the 12th ICCP held virtually due to the COVID-19 pandemic. Recently, 13th ICCP was hosted in Minneapolis, Minnesota, USA, from August 25 - 29, 2024, offering the latest developments in concrete pavement field. ISCP is dedicated to advancing knowledge, research, and innovation in the field of concrete pavements. Our Open Journal System provides a global platform for researchers, engineers, and professionals to share cutting-edge studies, case studies, and technical advancements related to the design, construction, performance, and maintenance of concrete pavements. By fostering an open-access approach, we aim to enhance collaboration, promote best practices, and support sustainable infrastructure development worldwide. We invite you to explore our peer-reviewed articles, submit your research, and contribute to the growing body of knowledge in this crucial field.
International Society for Concrete Pavements
ZERO-MAINTENANCE DESIGN FOR PLAIN JOINTED CONCRETE PAVEMENTS
This study outlines a design approach for plain jointed concrete pavements intended for heavy traffic, emphasizing a "zero-maintenance" performance over a designated period. The concept of "zero-maintenance" targets the absence of structural maintenance activities such as crack repair and slab replacement. Through extensive field surveys across various regions and comprehensive analytical studies using mechanistic models, researchers developed two distinct structural design approaches. One employs a new serviceability/performance model based on historical data from the original AASHO Road Test and other sources, while the other leverages a mechanistic fatigue analysis model to evaluate the impact of traffic load and environmental factors like thermal curling. The application of these models is supported by a novel computer program, JCP-1, designed to assist engineers in the rigorous design process. The procedures are validated by field data, ensuring their practical applicability for real-world engineering challenges. The study is backed by the Federal Highway Administration, highlighting its significance in advancing pavement engineering to meet modern traffic demands and environmental conditions. (Abstract generated by AI tool ChatGPT 4)
Copyright (c) 1977 Proceedings of the International Conference on Concrete Pavements
THE INFLUENCE OF CEMENT TREATED SUBBASES ON THE DESIGN OF AIRPORT P.C. CONCRETE PAVEMENTS
This study explores the influence of cement-treated subbases (CTS) on the design of airport Portland cement concrete (P.C.) pavements through both empirical research and theoretical modeling. Specifically, the research investigates how various characteristics of CTS, including modulus values and interface conditions (frictional properties), impact the performance and structural integrity of concrete slabs under airport pavement conditions. Using linear multilayered elastic models and finite element analysis, the study contrasts the impacts of different interface conditions (full friction versus no friction) and examines the effect of CTS thickness and modulus on stress distribution and deflection in the pavement system. The results from the modeling show that the presence and condition of the CTS significantly affect pavement performance, indicating specific thresholds for CTS thickness and stiffness to optimize pavement durability and minimize stress. These findings underscore the importance of meticulous design considerations in the construction of airport pavements to enhance their longevity and functionality. This research provides a comprehensive analysis that could guide future design improvements in airport pavement construction, particularly concerning the use of cement-treated subbases. (Abstract generated by AI tool ChatGPT 4)
THE DESIGN OF BRITISH AIRPORTS AUTHORITY PAVEMENTS
The article "The Design of British Airports Authority Pavements" by M.A.A. Calverley provides a comprehensive overview of pavement design and maintenance practices utilized by the British Airports Authority (BAA) across its seven major UK airports. This detailed examination covers the development, planning, design, and construction of new pavements and the maintenance of existing ones, with a focus on meeting or exceeding the standards set by the UK Civil Aviation Authority and international guidelines from ICAO. The paper highlights the adaptation of the Load Classification Group (LCG) system which incorporates modified Load Classification Numbers (LCN) to assess and design pavement strength based on aircraft weight and configuration, and the evolution of this system to accommodate increasing aircraft loads and ensure safety. The design strategies discussed include the use of Portland cement for rigid pavements due to its cost-effectiveness and durability compared to flexible pavement options. The document also discusses the operational challenges and environmental considerations at the BAA managed airports, emphasizing the need for pavements that are economical, durable, and minimally disruptive during maintenance. The approach taken by BAA not only ensures compliance with stringent safety and operational standards but also adapits to the ongoing changes in aircraft technology and airport operations. (Abstract generated by AI tool ChatGPT 4)
TESTING AND EVALUATION OF CONCRET AIRPORT PAVEMENTS
This report presents a test method by which it is possible to rapidly obtain information on bearing capacity and hemogeneity of concrete runways built on cement treated subbase materials. A light vibrator is used for this type of testing, and the measured deflections are brought into a precise relationship with the results of full-scale tests carried out with loads corresponding to those of a B 747 landing gear. The method is based on field experience from the runways of Zurich International Airport. A control of the method was done by comparing the test results from the two methods with the results of a multi-layer computer program simulating both field test conditions. An example is also given for the determination of evaluation criteria in the case of a concrete runway resting on top of an untreated gravel subbase.
SUMMARY AND EVALUATION OF CONCRETE PAVEMENT TEXTURING PRACTICES
The article "Summary and Evaluation of Concrete Texturing Practices" by E. E. Rugenstein provides an in-depth analysis of various concrete texturing methods used across the United States to improve roadway safety and manage surface water on pavements. It highlights the role of texturing in preventing hydroplaning and enhancing skid resistance, essential for modern high-speed traffic conditions. The article reviews different texturing techniques, such as burlap drag, wire broom, and transverse tine texturing, detailing their effectiveness and durability based on experiments conducted in states like Arizona, California, and Georgia, among others. The study identifies significant differences in the performance of longitudinal versus transverse textures, noting that longitudinal textures generally offer higher friction and better durability under conditions like snowplowing. It discusses the evolution of texturing practices, citing specific state-driven adaptations and the impacts of these adaptations on accident rates and pavement performance. For instance, California's study on longitudinally grooved pavements indicated a 69 percent reduction in wet pavement accidents. The findings and guidelines from organizations such as the American Concrete Paving Association and Federal Highway Administration are also discussed, which advocate for specific grooving patterns and depths to optimize skid resistance and manage water drainage effectively. The article concludes with recommendations for the construction and maintenance of textured pavements to ensure safety and durability, emphasizing the importance of uniform application techniques and the selection of appropriate texturing tools and materials. (Abstract generated by AI tool ChatGPT 4)
SUBGRADE SOILS: AN IMPORTANT FACTOR IN CONCRETE PAVEMENT DESIGN
In the article "Subgrade Soils: An Important Factor in Concrete Pavement Design" by Marshall R. Thompson and Barry J. Dempsey, the importance of subgrade soils in the design and performance of concrete pavements is thoroughly examined. The study elaborates on how subgrade conditions significantly impact the overall effectiveness and longevity of pavement systems, influencing not only the initial construction process but also the long-term operational stability. The paper discusses the critical influence of soil properties and climatic conditions on subgrade performance. Key factors such as water content, temperature, and soil composition (e.g., clay content and plasticity) are analyzed for their effects on the soil's strength and deformation properties. The resilience of subgrade soils under repetitive loads, known as the "resilient modulus," is highlighted as a vital parameter in assessing pavement durability and design adequacy. The research also explores the implications of environmental factors, emphasizing how moisture and temperature variations can drastically alter the physical properties of subgrade soils. It provides detailed insights into the methods for predicting these conditions and their integration into pavement design to enhance performance predictability. Overall, the article calls for a deeper understanding and more rigorous evaluation of subgrade soils in pavement engineering to ensure that designs are both effective in the short term and sustainable over the lifecycle of the pavement, considering the variable and often harsh environmental conditions these structures are subjected to. (Abstract generated by AI tool ChatGPT 4)
STEEL FIBROUS CONCRETE FOR AIRPORT PAVEMENTS
In the past several years, considerable interest has been generated in the use of steel fibrous concrete for pavements. Steel fibrous concrete is a composite material consisting of a concrete matrix containing a random dispersion of small steel fibers. The introduction of the fibers imparts to the concrete matrix certain characteristics, such as resistance to spalling, the ability to sustain load after initial cracking, and the ability to keep cracks tightly closed, which improve its performance compared to plain or conventionally reinforced concrete pavement. This paper contains a discussion of the properties of steel fibrous concrete, procedures for designing and constructing steel fibrous concrete airport pavements, and applications on airports.
SOME DESIGN CONSIDERATIONS FOR JOINTED REINFORCED CONCRETE PAVEMENTS (JRCP)
This paper examines the design considerations for Jointed Reinforced Concrete Pavements (JRCP), a critical component in modern road construction. It delineates the evolution of reinforced pavements, from early experiments in the 1910s to widespread use during the construction of the Interstate System. JRCP, often referred to as "mesh-dowel" pavement, balances the extremes of plain jointed and continuously reinforced concrete pavements by incorporating transverse joints and longitudinal ties, which help manage panel lengths and minimize cracking. The study highlights the components of JRCP, including the concrete slab, subbase, reinforcement, load transfer devices, and joint sealants, each playing a vital role in pavement performance. Reinforcement in JRCP aims to control cracking rather than prevent it, with less steel used compared to continuously reinforced options, thereby reducing costs while maintaining structural integrity. Load transfer mechanisms are emphasized as essential for accommodating heavy traffic and ensuring pavement longevity. The design also explores joint sealants and their role in preventing water ingress and damage from incompressible materials. Furthermore, the paper discusses various design methods for determining slab thickness and reinforcement, relying on both traditional formulas and modern approaches that consider traffic loads, environmental factors, and material properties. In conclusion, JRCP offers a balanced solution for pavement design, providing a compromise between durability and cost-effectiveness, suitable for diverse traffic and climatic conditions. This paper not only covers the historical perspective and current practices but also suggests innovative approaches for future advancements in pavement technology. (Abstract generated by AI tool ChatGPT 4)
This article provides a detailed review of the evolution of rigid pavement design for airfields, particularly under the purview of the U.S. Army Engineer Waterways Experiment Station in Vicksburg, Mississippi. Beginning with an urgent need for airfield pavements around the entry of the United States into World War II, the article tracks the development and implementation of pavement designs in response to escalating aircraft loadings and operational demands. Key to this development was the adoption of the Westergaard method for designing concrete slabs under load, which quickly became a standard due to its simplicity and practicality. The paper details several major phases of research and testing, including the initial static and dynamic tests on specially prepared slabs, the implementation of the subgrade modulus concept, and the progressive changes made to accommodate increasing loads from newer aircraft models like the B-52 and the strategic demands of the Cold War era. Notably, the investigation highlights the various modifications to the testing methods, especially the plate bearing tests which adapted over time to better represent the actual operational conditions of airfields. The narrative also delves into the challenges and innovations in pavement design introduced by the need for low-cost, high-performance airfield systems as dictated by evolving military and aviation standards. This includes the shift towards evaluating and implementing prestressed concrete pavements and the adjustment of design methodologies to better predict and manage the pavement life under increasingly heavy aircraft. Overall, the document serves as a comprehensive account of the technological and procedural advancements in airfield pavement design, reflecting decades of empirical research and theoretical analysis aimed at supporting military and civil aviation requirements efficiently and effectively. (Abstract generated by AI tool ChatGPT 4)
RECENT DEVELOPMENT IN THE DESIGN OF RIGID PAVEMENTS IN FRANCE. STUDY OF PERFORMANCE OF OLD PAVEMENTS AND CONSEQUENCES DRAWN FROM NEW HIGHWAY CONSTRUCTION
Concrete was used for pavements in France even before 1900, but; it was especially during the past 14 years that major superhighway construction projects made use of the Californian technique. There are presently about 500 kilometers of concrete­ paved superhighways in France. A very recent study of the performance of these superhighway pavements was conducted and this paper details the many investigations carried out. An assessment of the use of other concrete pavement construction techniques used throughout the world was also made and the reasons for the French choice are set out along with the latest modifications applied to French structural design. Finally, the research trends in France for the future are examined.
PRESTRESSED PAVEMENTS, THEORY INTO PRACTICE
This article explores the development and applications of prestressed concrete pavements, highlighting their distinct advantages in structural performance and maintenance compared to conventional concrete pavements. Introduced in the 1930s shortly after the advent of prestressed building structures, prestressed concrete has become a staple in bridge and building construction, yet its integration into pavement technology remains innovative. Prestressed pavements are crucial in overcoming the limitations of plain concrete's tension strength, which is essential given the tensile stresses pavements endure. The article details the evolution of pavement types in the U.S., focusing on their structural characteristics, costs, and the transition towards more sustainable and economically viable materials. With rising concerns about the longevity and efficiency of standard pavement designs, prestressed pavements offer a promising alternative that aligns with rapid construction practices necessary for economic feasibility. Furthermore, the paper discusses the specific applications of prestressed pavements in U.S. highways and airports, emphasizing the substantial cost benefits and performance enhancements over traditional methods. These pavements utilize post-tensioned steel to achieve desired stress levels and are constructed with innovations that reduce material use and energy consumption, aligning with broader environmental conservation efforts. In conclusion, the deployment of prestressed concrete pavements in highway and airport construction has demonstrated significant advantages in terms of structural performance and resource efficiency. This exploration underscores the potential for wider adoption of prestressed technology in pavement applications, promising enhanced durability and cost-effectiveness. (Abstract generated by AI tool ChatGPT 4)
PORTLAND CEMENT CONCRETE UTILIZING RECYCLED PAVEMENTS
This article investigates the innovative recycling of existing Portland cement concrete (PCC) pavements into new roadway materials. During a comprehensive project by the Iowa Department of Transportation, the practical and technical feasibilities of recycling PCC using local resources, labeled "Econocrete," were explored for base course construction. The chosen project involved a 1.476-mile stretch in Lyon County, Iowa, where old pavement was repurposed for the reconstruction of highway segments. This project demonstrated a pioneering recycling approach where old PCC and asphalt concrete pavements were crushed to specific sizes and then reused as aggregate in new concrete mix designs. The article delves into various aspects of the process, including material removal, crushing techniques, and mix design formulation, aiming to conserve resources and reduce environmental impacts. Experimental mixes using varying proportions of crushed concrete and natural sand were tested for strength and durability, aligning with standard pavement specifications but adjusted to incorporate recycled materials. The project revealed that such recycling is not only viable but also beneficial from both construction and environmental standpoints. Overall, the successful completion of the pavement segments using recycled aggregates illustrates the potential for broader application of this technique. It highlights the importance of proper mix design, material handling, and procedural adjustments to optimize the use of recycled materials in construction. This case study serves as a valuable reference for future projects aiming to enhance sustainability in civil engineering practices. (Abstract generated by AI tool ChatGPT 4)
The paper "Plain Pavement; An Economical Alternative" by Ralph C. Blum and Clinton E. Solberg examines the economic pressures faced by state transportation departments and the innovative measures implemented to reduce costs in highway construction. Focusing on the Wisconsin Department of Transportation (WDOT), the study details the transition from steel-reinforced concrete pavement to non-reinforced plain concrete pavement (PCP) in a 20-mile segment of Interstate Highway 43. This shift resulted in a significant cost reduction of $1.6 million. The authors discuss the historical context and economic analysis that influenced the decision, emphasizing the need for cost efficiency due to the declining purchasing power of state dollars and increasing construction material costs. The paper explores the construction process, the performance and maintenance of plain versus reinforced pavements, and the long-term economic and operational benefits. It concludes that the use of PCP not only offered immediate financial relief but also maintained quality and durability, making it a viable economic alternative for future highway projects. The findings suggest that PCP could potentially offer a sustainable model for managing limited resources while addressing the need for infrastructure development. (Abstract generated by AI tool ChatGPT 4)
PERFORMANCE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS IN INDIANA
Continuously reinforced concrete pavements (CRCP) represent a relatively recent development in concrete pavement technology. Their widespread use in recent years has met with mixed success. This study reports the findings of a detailed field investigation of in-service CRC pavements in Indiana. One of the objectives of this evaluation was to recommend design and construction guidelines that would help to improve CRCP performance. The study consisted of the following sequential steps: 1. Pavement condition surveys. 2. Detailed field testing and evaluation. 3. Laboratory testing program. A statistical analysis of the condition survey data showed that subbase type, methods of steel placement and steel fabrication, concrete slump, and age of pavement since opened to traffic were significant contributors to pavement performance. Based on these results, a field investigation of CRC pavements was conducted. ln this study, 31 test sections, each 1000 ft. in length, were used. As far as possible, each test section represented a unique combination of material, construction, traffic, and temperature variables. The results of the detailed field tests and laboratory studies showed that failures in CRCP are a function of a number of interacting variables. Generally, higher pavement deflection, decreased pavement stiffness, wider crack widths, and erratic non-uniform crack patterns were associated with failed pavement condition. The support conditions under CRCP were of particular significance relative to performance. Well-compacted granular subbases with high stability and good permeability (internal drainage) showed excellent performance. Failures on CRCP were found to be correlated with concrete having a relatively low bulk density and modulus of elasticity. It was observed that paving concrete with a relatively higher slump (minimum of 1.5 in.) was more suited to CRCP with respect to good performance. An analysis of CRCP design revealed that use of 0.6 percent steel was, at best, marginal. There were further indications that current CRCP thickness design may be inadequate to withstand the traffic loads imposed on Interstate Highways. The paper concludes with a set of construction and design guidelines that should help to improve the performance of CRCP in Indiana.
PERFORMANCE OF HEAVY-LOAD PORTLAND CEMENT CONCRETE (RIGID) AIRFIELD PAVEMENTS
This scientific article investigates the performance of heavy-load rigid airfield pavements constructed with Portland cement concrete. By focusing on 12 military airfields designed using Corps of Engineers criteria, the study assesses pavement lifespan and durability under actual aircraft traffic conditions compared to initial design predictions. It is revealed that many of these pavements, built across diverse environmental conditions and bearing various aircraft loads (up to 770,000 lb), generally perform well but vary in their rate of deterioration. The analysis combines physical condition surveys, including major and minor pavement defects, with detailed traffic data to evaluate the expended life of the pavements against their designed life expectancy. Results indicate that in many cases, the pavements underuse their projected service life, suggesting that the design criteria may be overly conservative. The study also touches on the repair and maintenance aspects of these pavements, highlighting the correlation between maintenance practices and pavement longevity. The findings advocate for ongoing adjustments to pavement design criteria based on empirical data from in-field performance, reinforcing the necessity for regular updates to engineering standards to accommodate actual usage patterns and environmental impacts. (Abstract generated by AI tool ChatGPT 4)
NAVY EXPERIENCE IN ELIMINATING KEYS FROM CONSTRUCTION JOINTS OF CONCRETE AIRFIELD PAVEMENTS
This study documents the U.S. Navy's shift from traditional keyed construction joints in airfield pavements to a simpler butt-joint design without keys or dowels, driven by recent increases in joint failures. Keyed joints, once standard for connecting concrete pavement slabs to prevent faulting and minimize stress, have been increasingly problematic, especially under heavy aircraft traffic like the C-141 and C-5A. Failures often result from poor concrete consolidation at joints, use of large aggregates, or stresses from construction equipment. The Navy has adopted the butt-joint design underlain by a high-quality stabilized base course, drawing on Californian highway practices. This approach sidesteps the complexities of dowel placement and key forming, especially in slipform paving. The article outlines the Navy's extensive operational experience with this design across various bases, showing favorable outcomes in reducing pavement stress and improving joint performance. Notably, the Santa Ana base has seen excellent durability with no key-related defects after eight years, supporting the design's efficacy. Furthermore, the butt-joint design not only facilitates slipform paving but also enhances the overall pavement structure due to the supportive properties of the stabilized base course. This transition reflects a significant shift in military infrastructure strategy, prioritizing long-term pavement integrity and operational safety over traditional construction methods. The findings advocate for wider adoption of this technique, potentially influencing civil aviation and roadway engineering practices. (Abstract generated by AI tool ChatGPT 4)
INVESTIGATION INTO THE PERFORMANCE OF RIGID PAVEMENT JOINTS AND SEALANTS
This study, conducted by the Georgia Department of Transportation, examines the effectiveness of various joint sealants in rigid pavements over a five-year period. Focusing on a test area along I-20 east of Atlanta, the research involved the construction of 32 test sections with different joint spacings and angles, utilizing eight types of sealants including polysulfide and polyurethane polymers, rubberized asphalt, neoprene, and polyvinylchloride (PVC). The study meticulously monitored the installation process to ensure optimal sealant performance. Key findings suggest significant differences in performance among the sealants, with specific recommendations against using polysulfide and polyurethane for contraction joints unless shape factors are modified. Moreover, the study emphasizes the importance of watertight seals to prevent pavement deterioration due to water ingress and subsequent base material loss, which can lead to slab cracking and reduced ride quality. Recommendations also include the potential use of low modulus silicone for sealing shoulder joints due to its durable and flexible properties, particularly in colder conditions. The study highlights the critical role of proper joint sealing in extending the lifespan and functionality of concrete roadways, providing essential insights for pavement maintenance and construction standards. (Abstract generated by AI tool ChatGPT 4)
IMPROVED BASE DESIGN FOR PORTLAND CEMENT CONCRETE PAVEMENTS
This paper investigates improved base designs for Portland Cement Concrete (PCC) pavements, analyzing their structural features and functional improvements to enhance pavement performance. The study highlights various base design innovations tested in California, such as the integration of a lean concrete base (LCB) and the adoption of a longitudinal drainage system. These advancements aim to mitigate common issues like pavement faulting, which deteriorates riding quality and structural integrity. Faulting is often triggered by slab curling, the presence of pumpable fines, and water beneath the slabs. By incorporating non-erodible materials and efficient drainage systems, the designs intend to extend pavement longevity and reduce maintenance needs. The paper delineates the experimental application of LCB in contrast to traditional cement-treated bases (CTB), demonstrating the superior uniformity and erosion resistance of LCB. It also discusses the effectiveness of longitudinal drains in removing water from the structural sections of pavements, thereby minimizing potential damage from water entrapment. Initial results from field trials suggest these design modifications not only improve pavement performance but also offer a cost-effective solution due to reduced thickness requirements and maintenance expenses. These innovative approaches are part of an ongoing effort to refine PCC pavement designs, aiming to enhance durability and performance while addressing the challenges posed by environmental and load conditions. Further research and large-scale testing will continue to optimize these designs, potentially revolutionizing PCC pavement construction and maintenance practices. (Abstract generated by AI tool ChatGPT 4)
EUROPEAN CONCRETE ROAD STANDARDS AND PRACTICES
The scientific article "European Concrete Road Standards and Practices" by Raymond Sharp provides a comprehensive overview of the current standards and practices in the construction of concrete roads across Europe, focusing on twelve countries: Austria, Belgium, Czechoslovakia, Denmark, France, Great Britain, Italy, the Netherlands, Spain, Sweden, Switzerland, and West Germany. The research synthesizes data from the Permanent International Association of Road Congresses (PIARC) and the European Cement Association, including detailed synoptic tables prepared for previous European symposia on concrete roads. This study delves into the various factors influencing pavement design, including traffic levels, sub-grade strength, and pavement materials, discussing the complexities of predicting future traffic and the insensitivity of pavement costs to small traffic variations. It examines the philosophical and economic decisions that guide pavement thickness and highlights the standardization in pavement design across different nations, emphasizing the small changes in design thickness due to the proven success and economic efficiency of existing systems. Furthermore, the paper explores the influence of non-technical factors such as governmental policies and competition between construction methods on pavement design. It also discusses the impact of local material availability and construction practices on the cost and quality of road construction. The research concludes that while concrete pavements generally perform well and offer long life spans, there are multiple viable approaches to pavement design influenced by local conditions and historical practices. It suggests that imposing a uniform design approach across different environments and traditions is impractical, advocating for flexible, context-specific solutions in pavement engineering. (Abstract generated by AI tool ChatGPT 4)
This paper outlines the development and utilization of Econocrete, a form of portland cement concrete specifically designed for paving applications where conventional aggregates are scarce or do not meet typical quality standards. Initiated by the American Concrete Paving Association's Technical Subcommittee on Materials and Mix Design in 1973, Econocrete aims to optimize the use of locally available aggregates that are typically deemed unsuitable for standard concrete due to inferior quality. Econocrete leverages such aggregates in the base course of composite pavement structures while reserving higher quality aggregates for the surface course, which is more exposed to wear and environmental conditions. The study describes various test programs conducted across states like Florida, Georgia, South Carolina, and Iowa, evaluating different aggregate types that do not meet the conventional standards for pavement concrete but could be viable for Econocrete. This includes aggregates with high fines content, poor abrasion resistance, and others typically excluded from standard use due to performance issues at the pavement surface. Through comprehensive research and testing, the subcommittee developed mix designs that address the specific environmental and service requirements of the regions, allowing for economic and ecological benefits by reducing transportation costs and using less desirable local resources effectively. The paper also explores the broader applications of Econocrete in constructing durable and cost-effective pavements, subbases, and shoulders, potentially increasing the lifespan and performance of roadways while accommodating various traffic volumes and environmental conditions. This innovation not only offers a practical solution to the diminishing supply of conventional aggregates but also represents a significant advancement in sustainable pavement technology. (Abstract generated by AI tool ChatGPT 4)
DRAINAGE OF CONCRETE PAVEMENT STRUCTURES
This article, authored by George W. Ring III, addresses the critical issue of subsurface drainage in the performance of concrete pavements. It highlights the often overlooked fact that water trapped beneath pavement slabs can cause significant damage, including subgrade support reduction, faulting at joints, and accelerated deterioration of the concrete. The study draws on data from various interstate studies and long-term road life studies, which collectively demonstrate that effective drainage systems vastly enhance pavement longevity and performance. The paper asserts that current design standards for concrete pavements often neglect adequate drainage solutions, focusing instead on thickness and material strength to counteract the effects of water. Ring argues for the inclusion of drainage considerations in pavement design criteria to prevent water-related damages such as pumping, faulting, and erosion of subgrade and subbase materials. He discusses the historical evolution of pavement drainage design and emphasizes the importance of both surface and subsurface drainage systems. Through detailed analysis and reference to pioneering work, Ring outlines the necessary steps for designing effective drainage systems and the need for further research in improving these systems. In conclusion, the article calls for a shift in engineering practices towards incorporating comprehensive drainage solutions in pavement designs to ensure better performance and durability. Ring's insights advocate for a more holistic approach to pavement design, integrating both structural integrity and efficient water management to mitigate the adverse effects of water on pavement systems. This comprehensive perspective aims to extend the lifespan of pavements and reduce maintenance costs over time. (Abstract generated by AI tool ChatGPT 4)
DRAINAGE CONSIDERATIONS TO MINIMIZE DISTRESS AT THE PAVEMENT-SHOULDER JOINT
This study investigates the challenges and solutions associated with water-related distress at the pavement-shoulder joint in highway systems, particularly where Portland cement concrete pavements meet asphaltic concrete shoulders. The joint between the pavement and shoulder is identified as a critical weakness, where water infiltration leads to various forms of deterioration such as cracking, settlement, and structural damage. These effects are exacerbated by frost heave in northern climates and heaving of expansive subgrade soils in both warm and cold regions. The research underscores the significance of efficient drainage systems to mitigate these problems. Field studies and laboratory experiments demonstrate that rapid removal of surface water from beneath the pavement and shoulder structures significantly reduces the severity of water-associated issues. Key to this process is the design and implementation of highly permeable drainage layers and effective drainage systems that ensure the quick expulsion of water. The use of open-graded, asphaltic concrete base course mixes, which provide both structural support and drainage capabilities, is advocated. The paper details the design considerations for these drainage systems, emphasizing the importance of permeability and the quick removal of water to prevent damage. It highlights the necessity of integrating proper drainage facilities during the construction and maintenance of highways to extend the lifespan of pavement structures and reduce maintenance costs and safety hazards. This comprehensive approach not only addresses groundwater but also manages surface infiltration, which is equally detrimental to the pavement-shoulder integrity. (Abstract generated by AI tool ChatGPT 4)
DESIGN AND CONSTRUCTION Of CONCRETE PAVEMENTS
This article presents a comprehensive study of concrete pavement design and construction in the United States, focusing on the performance, cost-effectiveness, and regional usage of different concrete pavement types. Initiated in 1975 by the Portland Cement Association under the sponsorship of the Federal Highway Administration, this study surveyed all state highway or transportation departments to collect data on concrete pavement design specifications, construction costs, and performance across various regions. Four main designs were analyzed: plain concrete, plain doweled concrete, conventionally reinforced doweled concrete, and continuously reinforced concrete, each with distinct characteristics concerning joint reinforcement and load transfer. The study is divided into three main sections: design preferences and specifications across states, cost analysis considering initial construction and maintenance, and field surveys evaluating pavement performance. It highlights regional differences in design practices influenced by climate, subgrade conditions, and other environmental factors. Performance data from field surveys across several states provided insights into the distress patterns associated with each pavement type, informing recommendations for design and construction improvements. Key findings include the significant impact of dowels on reducing joint faulting and the comparative cost-effectiveness of different pavement designs when considering long-term maintenance. The study also emphasizes the need for adequate joint sealant design and the benefits of stabilized subbases in enhancing pavement durability. The article concludes with specific recommendations for improving concrete pavement performance, focusing on joint design, material selection, and the strategic use of dowels and reinforcements to mitigate common pavement distresses and enhance overall serviceability. (Abstract generated by AI tool ChatGPT 4)
DESIGN PROCEDURE FOR CRCP BASED ON LABORATORY AND FIELD OBSERVATIONS
In this paper a CRCP design procedure is presented along with the necessary limiting criteria. The procedure is derived from theoretical and empirical models developed in connection with numerous field and laboratory studies. The first basic concept is to provide adequate longitudinal steel considering the specific conditions of a project to achieve a desirable crack width, crack spacing, and steel stress. These limiting criteria are shown in the report. A check is also made to limit spalling and other distress manifestations from occurring. The AASTO Guide for Design of Pavement Structures is recommended for pavement thickness design.
This article by Robert G. Huber explores the evolution and benefits of low volume concrete roads, focusing on the pioneering use of the slipform paving method in Iowa. It traces the origins back to 1946 when James W. Johnson conceptualized a machine that laid concrete without the need for side forms. Successive developments led to the creation of more advanced machines, with the first practical applications on county highways by the late 1940s. By the 1950s, the method had spread beyond Iowa, as other states and equipment manufacturers recognized the efficiency and cost-effectiveness of slipform paving. Notably, the slipform paver underwent significant improvements, facilitating its adoption for wider use. The paper details the specific adjustments in design and operation made in Iowa, such as the adoption of Type B concrete with varying cement content suitable for local conditions, and adjustments to subgrade preparation to enhance durability and performance. It also discusses the economic benefits, highlighting significant cost savings over traditional paving methods, alongside the reduced maintenance costs observed in Washington County. Furthermore, Huber elaborates on the broader adoption of slipform paving, predicting its dominance in the paving industry. The narrative is supported by data on road paving activities and costs over the years, providing a comprehensive view of the method’s impact on road construction in Iowa. This historical and technical account not only underscores the innovation's practicality but also its role in advancing road construction technology, making a case for its continued use and development. (Abstract generated by AI tool ChatGPT 4)
DESIGN CRITERIA FOR CONTINUOUSLY REINFORCED CONCRETE OVERLAY BASED ON PERFORMANCE
This scientific article by Karl H. Renner discusses the design criteria for continuously reinforced concrete pavement (CRCP) overlays, focusing on performance-based improvements for deteriorating sections of the U.S. Interstate Highway system. The paper highlights the challenges posed by existing pavements, including their inadequate design to handle unanticipated heavy traffic loads and environmental stressors. The author evaluates the effectiveness of CRCP overlays in extending the lifespan and durability of these pavements by conducting a comprehensive survey of 23 highway projects across 13 states. Renner elaborates on the advantages of CRCP overlays, such as improved structural integrity, reduced maintenance costs, and better load transfer without the need for frequent joint repairs, which conventional pavements require. The article also covers the technical aspects of overlay design, including the importance of uniform overlay thickness, the role of steel reinforcement, and the introduction of leveling courses to mitigate issues arising from non-uniform base conditions. The study concludes that CRCP overlays, while initially more expensive, offer long-term economic benefits and superior performance compared to other resurfacing methods. The findings advocate for their use in rehabilitating existing pavements to meet current and future traffic demands effectively. This comprehensive approach not only enhances pavement durability but also contributes to a better understanding of overlay design practices, paving the way for further research and development in pavement engineering. (Abstract generated by AI tool ChatGPT 4)
DESIGN CONCEPTS OF CONCRETE PAVEMENTS IN EUROPE
This scientific article, authored by Prof. R. Springenschmid, explores the diverse design concepts of concrete pavements across Europe, emphasizing the varied approaches and specifications employed in different countries. It details how European nations have shifted from using long, reinforced concrete slabs to shorter, unreinforced slabs without expansion joints, adapting to new research and technologies like slipform pavers and dowels at transverse joints. The article highlights the extensive use of concrete pavements in motorways and airports across Europe, with a focus on innovative practices like the use of prestressed pavements in heavy-duty applications. Significant emphasis is placed on the evolution of design practices, influenced heavily by both practical experience and theoretical advancements. It discusses how different countries have adapted their specifications to accommodate local conditions such as climate and traffic, without a unified European standard. The integration of theoretical models, especially from research in Belgium and France, has propelled forward the understanding of stress calculations and pavement behavior under various loads. The research also addresses specific challenges like thermal and shrinkage stresses, and the role of subbases in pavement performance. The narrative concludes by contemplating the future of pavement designs, advocating for a balance between empirical practices and theoretical insights to enhance pavement longevity and functionality. This comprehensive review not only serves as a testament to the dynamic nature of concrete pavement engineering in Europe but also as a foundation for further research and development in the field. (Abstract generated by AI tool ChatGPT 4)
DESIGN CONSIDERATIONS FOR CONTROL OF JOINT FAULTING OF UNDOWELED PAVEMENTS
Based on a study of the performance of undoweled concrete pavements, it is concluded that the degree of joint faulting depends on the number of heavy trucks carried, slab thickness, joint spacing, and the type of subbase and subgrade. The effect of different degrees of joint faulting on the quality of ride, or serviceability, of pavements is evaluated. A correlation of the faulting data provides an improved method for predicting the degree of faulting and serves as a more definite basis than previously available to decide whether or not a doweled joint design is required. The fault prediction model may also be used, with stated, limitations, to estimate the required thickness of undoweled pavements designed thicker than conventional doweled pavements to compensate for the absence of dowels. The results are intended to apply to the design of highway and street pavements with short joint spacings.
CONCRETE ROAD EXPERIENCE IN GREAT BRITAIN 1969-1975
The scientific article "Concrete Road Experience in Great Britain 1969-1975" provides a comprehensive analysis of the developments in concrete road construction within Great Britain during the specified period, with a focus on design evolution, experimental outcomes, and specification changes. The study details historical shifts in concrete road technology, particularly in the design and construction techniques, which have been influenced by extensive experimental research and field observations by the Road Research Laboratory and other bodies. Innovations such as the adjustment in the thickness and reinforcement of concrete slabs based on traffic load and subgrade conditions, the introduction of load transfer devices like dowel bars, and the utilization of air-entrained concrete mixes for enhanced durability are highlighted. The paper also addresses ongoing issues such as pavement cracking and the resulting maintenance challenges. Key outcomes include the implementation of more scientific design approaches leading to the first design recommendations in 1955, later updates in the 1960s and 1970s, and the consequent rise in concrete road construction following these publications. However, despite these advancements, challenges in surface texture and ride quality persist, indicating the need for continuous improvement in construction practices and materials technology. The insights derived from these experiences contribute significantly to the evolution of road construction methodologies, aiming to enhance the longevity and functional quality of concrete pavements. (Abstract generated by AI tool ChatGPT 4)
CONCRETE PAVEMENT DESIGN FOR CANADIAN AIRFIELDS
A brief synopsis is given of Transport Canada structural design practices for the provision of airfield concrete pavements at Canadian airports. Design considerations in related areas of construction, operations and evaluation are also discussed in a general manner. A detailed treatment of standards and practices may be found in the Transport Canada manuals listed in the references.