Performance Based Characterization of Virgin and Recycled Aggregate Base Materials

Performance Based Characterization of Virgin and Recycled Aggregate Base Materials
Author: Mohammad Ahmeduzzaman
Publisher:
Total Pages: 0
Release: 2016
Genre:
ISBN:

Characterization of the effect of physical properties on the performance such as stiffness and drainage of unbound granular materials is necessary in order to incorporate them in pavement design. The stiffness, deformation and permeability behaviour of unbound granular materials are the essential design inputs for Mechanistic-Empirical Pavement Design Guide as well as empirical design methods. The performance based specifications are aimed to design, and construct a durable and cost effective material throughout the design life of a pavement. However, the specification varies among jurisdiction depending on the historical or current practice, locally available materials, landform, climate and drainage. A literature review on the current unbound granular materials virgin and recycled concrete aggregate base construction specification has been carried out in this study. Resilient modulus, permanent deformation and permeability tests have been carried out on seven gradations of materials from locally available sources. Resilient modulus stiffness of unbound granular material at two different conditioning stress level have been compared in the study. The long term deformation behaviour has also been characterized from results of the permanent deformation test using shakedown approach, dissipated energy approach and a simplified approach. The results show improvement in resilient modulus and permanent deformation for the proposed specification compared to the currently used materials as a results of reduced fines content, increased crush count and inclusion of larger maximum aggregate size into the gradation. A significant effect of particle packing on permeability of granular materials have also been found, in addition to the effect of fines.

Performance Related Tests on Recycled Materials for Sustainable Design of Pavement Systems

Performance Related Tests on Recycled Materials for Sustainable Design of Pavement Systems
Author: Athar Saeed
Publisher:
Total Pages: 16
Release: 2011
Genre: Aggregate base
ISBN:

This paper provides recommendations for performance-related tests to select recycled materials to be used in pavement foundations (base/sub-base layers). The test protocol presented in this paper will help transportation agencies, pavement design engineers and construction industry professionals to mechanistically evaluate and select sources of recycled hot-mix asphalt and portland cement concrete materials and identify factors that contribute most to the longevity of layers using recycled pavement materials. Extensive literature review was conducted on the aggregate specifications in the United States and other countries to identify the protocols used to evaluate the suitability of virgin and recycled aggregates in base and sub-base layers. The test procedures, typically designed for virgin aggregates, were modified to account for the recycled materials in the aggregate mix. The test procedures were further evaluated on the basis of mechanical performance, accuracy, practicality, complexity, precision, and test cost. The performance of the developed aggregate evaluation systems was determined through testing and analysis of 12 aggregates with different lithology and known field performance history. These samples were selected from seven states with different seasonal frost cycles. The performance tests were conducted and modifications were made to the tests procedures to better understand the mechanical behavior of aggregate systems with recycled materials. This study revealed that shear strength, toughness, abrasion, durability, and frost susceptibility influence the performance of the unbound aggregate layers. Statistical analysis of the data showed that shear strength of the aggregate systems has the most impact on the performance of the unbound systems consisted of recycled materials.

Systematic Approach of Characterisation and Behaviour of Recycled Aggregate Concrete

Systematic Approach of Characterisation and Behaviour of Recycled Aggregate Concrete
Author: M. Chakradhara Rao
Publisher: Springer
Total Pages: 349
Release: 2018-06-16
Genre: Technology & Engineering
ISBN: 9811066868

This book focuses on the utilisation of construction waste material as coarse aggregate in making concrete. It discusses in detail the behaviour of recycled aggregate under impact load along with other structural applications, and explains the various quality-improvement techniques for recycled aggregate and recycled aggregate concrete (RAC). The first chapter describes the importance of recycling construction and demolition waste and the status quo of global construction and demolition waste recycling. The second chapter examines the recycled aggregate production methodology. Subsequent chapters address the physical and mechanical characteristics and different research findings, as well as the engineering properties of recycled aggregate concrete. Further, the interrelationships among the mechanical properties of recycled aggregate concrete are discussed. The book also explores long-term properties like shrinkage and creep, durability properties, and microstructural characterisation. It will serve as a valuable resource for researchers and professionals alike.

Initial Report on Experimental Project "Recycling of Asphaltic Concrete Pavements"

Initial Report on Experimental Project
Author: Wyoming. State Highway Department
Publisher:
Total Pages: 116
Release: 1979
Genre: Pavements
ISBN:

A primary problem associated with recycling is the pollution created by the combustion of asphaltic material during heating in a conventional drum dryer. Also of importance is the aging characteristics of recycled materials and their performance. This report covers the testing and design methods, construction procedures, resulting air pollution, economy of operation, and performance of a pavement recycled and utilized as a surface course in southeastern Wyoming.

Characterization of Recycled Concrete Aggregates (RCA) from an Old Foundation Structure for Road Pavement Works

Characterization of Recycled Concrete Aggregates (RCA) from an Old Foundation Structure for Road Pavement Works
Author: Moses Akentuna
Publisher:
Total Pages: 208
Release: 2013
Genre:
ISBN:

The use of recycled concrete aggregates in Portland cement concrete and granular road base or sub-base works has increased steadily all over the world in order to conserve the limited natural aggregate deposits. The recycling of the demolished concrete aggregate for the use in concrete or granular pavement works will not only help to protect the environment but also an economical benefit to the user. The main drawback for the bulk utilization of demolished or recycled aggregate is its characterization and proper quality control during its production. The overall objective of this research was to characterize recycled concrete aggregates (RCA) obtained from a demolished foundation structure and to determine its suitability for Portland Cement Concrete (PCC) works and use as a granular road base or sub-base material. Tests were carried out on RCA samples to determine whether it meets the specification for concrete aggregate material or a granular road base and sub-base materials. Several concrete mixes consisting of 10, 20, 30, 40, 60, and 80 % replacement of natural coarse aggregates (NCA) with RCA were prepared and tested for compressive strength after curing periods of 7, 14, and 28 days. The compressive strength of concrete made with various percentages of RCA decreased with increasing RCA content but it increased with curing period for all concrete mixes. The durability parameters of the natural aggregates and RCA samples were investigated by using sulfate soundness, rapid freeze-thaw and micro-deval tests to ascertain their chemical and abrasive resistance. The California Bearing Ratio (CBR) of RCA base was also compared with that of a natural road base material to determine its suitability for road base or sub-base works. In this study, the flakiness and elongation indices of the RCA were found to be better than that of conventional natural aggregates. The RCA base material had lower maximum dry density, higher optimum moisture content, and low California Bearing Ratio (CBR) value compared to the natural crushed rock base (NCRB) material but was found to be a relatively good road base material.

Performance-related Tests of Recycled Aggregates for Use in Unbound Pavement Layers

Performance-related Tests of Recycled Aggregates for Use in Unbound Pavement Layers
Author: Athar Saeed
Publisher: Transportation Research Board National Research
Total Pages: 66
Release: 2008
Genre: Technology & Engineering
ISBN:

Explores performance-related procedures to test and select recycled hot-mix asphalt and portland cement concrete materials for use in unbound layers of highway pavements. Appendixes A through C of NCHRP Report 598, which cover the literature review and background information, new aggregate tests, and surface dielectric measurements, were published as NCHRP Web-Only Document 119.

Recycled Aggregates

Recycled Aggregates
Author: Ravindra K Dhir
Publisher: ICE Publishing
Total Pages: 0
Release: 2019-09-09
Genre: Technology & Engineering
ISBN: 9780727764638

The book is an ideal source of information on the subject and would be a suitable addition to any library as a resource for researchers seeking to develop an overview of the research on this topic.

Recycled Aggregate in Concrete

Recycled Aggregate in Concrete
Author: Jorge de Brito
Publisher: Springer Science & Business Media
Total Pages: 453
Release: 2012-11-28
Genre: Technology & Engineering
ISBN: 1447145402

Concrete is the most used man-made material in the world since its invention. The widespread use of this material has led to continuous developments such as ultra-high strength concrete and self-compacting concrete. Recycled Aggregate in Concrete: Use of Industrial, Construction and Demolition Waste focuses on the recent development which the use of various types of recycled waste materials as aggregate in the production of various types of concrete. By drawing together information and data from various fields and sources, Recycled Aggregate in Concrete: Use of Industrial, Construction and Demolition Waste provides full coverage of this subject. Divided into two parts, a compilation of varied literature data related to the use of various types of industrial waste as aggregates in concrete is followed by a discussion of the use of construction and demolition waste as aggregate in concrete. The properties of the aggregates and their effect on various concrete properties are presented, and the quantitative procedure to estimate the properties of concrete containing construction and demolition waste as aggregates is explained. Current codes and practices developed in various countries to use construction and demolition waste as aggregates in concrete and issues related to the sustainability of cement and concrete production are also discussed. The comprehensive information presented in Recycled Aggregate in Concrete: Use of Industrial, Construction and Demolition Waste will be helpful to graduate students, researchers and concrete technologists. The collected data will also be an essential reference for practicing engineers who face problems concerning the use of these materials in concrete production.

Use of Recycled Aggregate Materials Characteristics in Pavement Design Analyses

Use of Recycled Aggregate Materials Characteristics in Pavement Design Analyses
Author: Ida Gheibi
Publisher:
Total Pages: 172
Release: 2020
Genre: Electronic dissertations
ISBN:

Use of recycled materials promotes sustainability in roadway construction by reducing consumption of energy and emission of greenhouse gases associated with mining and the production of natural aggregates. Recycled asphalt pavements (RAP) and recycled concrete aggregates (RCA) have comparable characteristics to natural aggregates that are currently used in roadway base course applications. This study has developed a database for RAP and RCA materials' characteristics including resilient modulus (Mr), California bearing ratio (CBR), gradations along with construction specifications. RAP and RCA relationships with different engineering and index properties were investigated and some trends were proposed such as higher RAP content reveals higher summary of resilient modulus (SMr), higher RCA content causes higher optimum moisture content (OMC) and lower maximum dry unit (MDU).In addition, pavement mechanistic-empirical (ME) analyses have been conducted with the material inputs collected for the database to determine whether different values of different characteristics of RCA and RAP can be used in flexible or rigid pavement designs. Results showed that Mr parameter had the highest impact on pavement distress predictions among gradations and hydraulic conductivity.

Sustainable Construction Materials

Sustainable Construction Materials
Author: Ravindra K. Dhir OBE
Publisher: Woodhead Publishing
Total Pages: 652
Release: 2019-01-05
Genre: Architecture
ISBN: 0081009917

Sustainable Construction Materials: Recycled Aggregate focuses on the massive systematic need that is necessary to encourage the uptake of recycled and secondary materials (RSM) in the construction industry. This book is the fifth and the last of the series on sustainable construction materials and like the previous four, it is also different to the norm. Its uniqueness lies in using the newly developed, Analytical Systemisation Method, in building the data-matrix sourced from 1413 publications, contributed by 2213 authors from 965 institutions in 67 countries, from 1977 to 2018, on the subject of recycled aggregate as a construction material, and systematically analysing, evaluating and modelling this information for use of the material as an aggregate concrete and mortar, geotechnics and road pavement applications. Environmental issues, case studies and standards are also discussed. The work establishes what is already known and can be used to further progress the use of sustainable construction materials. It can also help to avoid repetitive research and save valuable resources. The book is structured in an incisive and easy to digest manner and is particularly suited for researchers, academics, design engineers, specifiers, contractors, and government bodies dealing with construction works. Provides an exhaustive and comprehensively organized list of globally-based published literature spanning 5000 references Offers an analysis, evaluation, repackaging and modeling of existing knowledge that encourages more responsible use of waste materials Provides a wealth of knowledge for use in many sectors relating to the construction profession, including academia, research, practice and adoption of RSM