Aggregate Tests for Portland Cement Concrete Pavements


Book Description

"This digest summarizes the findings from NCHRP Project 4-20C, 'Aggregate Tests Related to Performance of Portland cement concrete Pavements: State of the Knowledge.' It was prepared by Dr. Amir N. Hanna ... from the contractor's final report authored by Dr. Kevin J. Folliard and Mr. Kurt D. Smith ..."--Page 1







Portland Cement Concrete Pavements


Book Description

In conducting this investigation, detailed surveys on 85 pavement projects in 7 States were made. These pavements were generally under 15 years old, and reinforced and continuously reinforced pavements. The results of this investigation are contained in the report as prepared by PCA. Some of the aspects of Portland Cement Concrete pavements covered include: 1) Categories and characteristics of PCC pavements; 2) Pavement problems, their causes and required maintenance; 3) A pavement performance and condition survey; 4) A charted summary, design, and construction practices of the states (available separately on request); 5) Construction and maintenance costs, and 6) Design and construction recommendations.













Effects of Aggregate Blends on the Properties of Portland Cement Concrete Pavements


Book Description

Although recent studies have shown that pavement performance does vary by aggregate type, current portland cement concrete pavement design tools do not fully incorporate aggregate properties into the design process. Aggregate characteristics shown to affect pavement performance include strength, thermal properties, and shrinkage properties. The objective of this study was to investigate the material properties of crushed limestone and siliceous river gravel, two aggregates predominantly used in current pavement construction, and to determine a relationship between the properties of single-aggregate concrete and concrete made with predetermined blends of limestone and gravel. This report continues the work of Project 422/1244, which was limited to single-aggregate concretes. Additional models were developed to predict concrete properties of blended aggregate concrete for use in the design tools, CRCP and JRCP, described in previous 422/1244 reports. A computer program, CHEM2, was developed, which allows the pavement designer to estimate the material properties of concrete from an inexpensive chemical test.




Defining the Attributes of Good In-service Portland Cement Concrete Pavements


Book Description

Much of the current research in portland cement concrete (PCC) pavements deals with the analysis of early pavement life failures and seeks to find ways to prevent those from reoccurring. The Long Term Pavement Performance (LTPP) portion of the Strategic Highway Research Program (SHRP) has identified some of the key factors in designing and building new PCC pavements. This statement will build on the Iowa Highway Research Board (IHRB) project TR-463, Field Performance Study of Past Iowa Pavement Research: A Look Back. In Iowa and across the nation, there are multiple pavements that were built more than 20 years ago that have been and are continuing to provide very good service to the public. They are found on both state and local routes and in both low and high traffic volume areas. There is a need to learn what went into those pavements, from the subgrade through the surface, that makes them perform so well. The purpose of this research project was to conduct a scoping study that could be used to evaluate the need for additional research to study the attributes of well-performing concrete pavements. The concept of zero-maintenance jointed plain concrete pavements was iterated in this study for long-lasting, well-performing portland cement concrete pavement sections. The scope of the study was limited to a brief literature survey, pavement performance data collection from many counties, cities, and primary and interstate roads in Iowa, field visits to many selected pavement sites, and analysis of the collected data. No laboratory or field testing was conducted for this phase of the project. A problem statement with a research plan was created that could be used to guide the second phase of the project.