Predicting Coarse Aggregate Performance Using the Micro-Deval Test with Strength and Intrinsic Particle Property Tests


Book Description

Numerous tests exist in the field of aggregate qualification which have little to no relation to field performance. Many aggregate sources have been restricted in their use due to non-conforming results from a test that has little relation to field performance. Many aggregates have also been used in projects because of acceptable test results but have resulted in premature and costly repairs. The aggregate industry needs a test that better correlates test results to field performance. Micro-Deval has shown potential as a good indicator for field performance. The micro-Deval wet abrasion test for coarse aggregate is studied to determine the ability of the test to predict field performance for various uses and mineralogical backgrounds when used in combination with other aggregate tests. Forty-two aggregates were obtained from across the United States and Canada with varying field performance ratings, uses, and mineralogy. General correlations are developed between the micro-Deval test and other laboratory tests as well as determining the ability of the micro-Deval test to predict field performance when used in combination with other laboratory tests




The Prediction of Coarse Aggregate Performance by Micro-Deval and Other Soundness, Strength, and Intrinsic Particle Property Tests


Book Description

This research project concentrated on determining whether or not a correlation existed between laboratory aggregate tests and observed aggregate field performance. For this purpose, aggregate samples were collected from the majority of the U.S. states as well as several Canadian provinces and subjected to a variety of strength, soundness, and intrinsic particle property tests. Additionally, performance data on the aggregates was obtained by contacting multiple DOT's where aggregates were in use in several categories - hot-mix asphalt, portland cement concrete, base course, and open-graded friction course. Numerical and qualitative analyses were performed to evaluate the success of separating good performers from fair and poor performers using the micro-Deval test alone as well as the micro-Deval test combined with another test. Furthermore, attempts were made to determine if a correlation exists between any two tests.




Investigation of Testing Methods to Determine Long-term Durability of Wisconsin Aggregates


Book Description

Approximately 10 to 11 million tons of aggregates are utilized in transportation infrastructure projects in Wisconsin annually. The quality of aggregates has a tremendous influence on the performance and durability of roadways and bridges. In this Phase II research study, detailed statistical analyses were performed on over 1,000 sets of historical aggregate test results and the experimental results from the Phase I study. Test results from other states were analyzed as well. Aggregate tests were performed on 12 known marginal or poor Wisconsin aggregates to specifically address test performance of such aggregates. Selected aggregates were scanned using X-ray computed tomography to assess the effects of freeze-thaw and sodium sulfate exposure on the internal void system. The results of multi-parameter logistic regression analyses show that the pass/fail outcomes of the Micro-Deval test can be predicted when LA abrasion, absorption, and sodium sulfate soundness test results are known. The unconfined freeze-thaw test outcomes cannot be predicted from results of other tests (not correlated). Therefore, the unconfined freeze-thaw test should be part of any test protocol as it measures an aggregate characteristic that cannot be obtained from other tests. The percentiles associated with any proposed acceptance threshold limits for various aggregate tests should be determined using the statistical data provided.




The Prediction of Coarse Aggregate Performance in Portland Cement Concrete and Open-graded Friction Course by Micro-Deval and Other Aggregate Tests


Book Description

The research findings presented is this thesis are one portion of a four-part report on the prediction of coarse aggregate performance in hot-mixed asphalt, portland cement concrete, base course, and open-graded friction course by micro-Deval and other aggregate tests. This thesis contains discussions of the results and correlations for portland cement concrete and open-graded friction course as well as a several rock type subgroups of hot-mixed asphalt. The research involved 117 different coarse aggregate sources and performance data gathered from 35 transportation agencies. Each source was subjected to thirteen aggregate tests including micro-Deval. The results for each test alone and in combination with other tests were analyzed for correlations with field performance.




Fundamentals of Durable Reinforced Concrete


Book Description

This new edition sets out the fundamental aspects of concrete durability with an emphasis on sustainability and carbon neutrality through performance-based methodologies. Global approaches to managing durability are explained from both a prescriptive and performance viewpoint. Achieving a balance between the interactive factors influencing durability and sustainability is supported by an explanation of the physical and chemical phenomena at play, determination of key performance parameters by mathematical modelling and physical testing, and current guidance for good practice. New chapters and sections examine the holistic approach to durability and significant aspects of traditional and new cementitious systems. The full range of threats to durability are covered in this single volume, including reinforcement corrosion, carbonation, chloride ingress, freeze-thaw effects, sulfate attack, acid and seawater attack, alkali-aggregate reaction, cracking, abrasion, erosion, cavitation, and weathering. The book presents a framework for specification through internationally adopted codes and standards and summarises the background to probabilistic approaches to durability design, providing a state-of-the-art review of mathematical modelling of deterioration mechanisms along with current directions in test methods for performance-based specifications. Fundamentals of Durable Reinforced Concrete is an essential reference on concrete durability for specifiers and researchers and is also accessible to undergraduate students.







Use of the Micro-Deval Test for Assessing the Durability of Virginia Aggregates


Book Description

Aggregate is one of the most widely used construction material, and the key aspect of aggregate quality is durability. In this study, the Micro-Deval test, a new test developed in France and modified by Canadians, was studied to evaluate its suitability in assessing the durability of coarse and fine aggregates from Virginia sources. The Micro-Deval and several known aggregate tests were compared. The Micro-Deval test showed a very high potential in evaluating aggregate durability with higher precision and accuracy than the conventional tests such as the magnesium sulfate and Los Angeles abrasion tests. The Micro-Deval test was able to differentiate between good and poor performing aggregates at least 70 percent of the time and was able to identify the quality difference between similar aggregate types with varying degrees of weathering. Because of the study findings, the researchers recommend that the Micro-Deval test be used as a quality control tool for aggregate assessment to supplement the current measures of aggregate quality.







Advances in Aggregates and Armourstone Evaluation


Book Description

The maintenance and upgrading of our built environment, including large sections of coastal defences, relies heavily on natural construction materials. The text aims to highlight a range of pressing research issues in natural construction materials of direct relevance to an industry facing growing pressures for environmental sustainability and standardization of product quality within Europe. Tests and specifications given in the forthcoming Eurostandards for aggregates and armourstones are considered and correlated with older more widely used tests, including those which could impact upon current road safety. This text should be useful to: aggregate and amourstone suppliers and users; civil and engineering geologists; quarry companies; and Local and County Authority engineers and coastal engineers.




Tests for Mechanical and Physical Properties of Aggregates. Determination of the Resistance to Wear (Micro-Deval)


Book Description

Aggregates, Cement and concrete technology, Mechanical properties of materials, Physical properties of materials, Wear tests, Abrasion, Mechanical testing, Test equipment, Test specimens, Specimen preparation, Reproducibility, Ballast (aggregates)