Download or read book Recycled Asphalt Pavement as Coarse Aggregate Replacement in High Strength Portland Cement Concrete Mixes written by Tara R. Capson and published by . This book was released on 2014 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility of Reclaimed Asphalt Pavement as Aggregate in Portland Cement Concrete written by Michael Berry and published by . This book was released on 2013 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research effort was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as aggregate replacement in concrete pavements. This research demonstrated that concretes with up to 50 percent of the fine aggregates and 100 percent of the coarse aggregates replaced with RAP were suitable for concrete pavement. A statistical experimental design procedure (response surface methodology - RSM) was used to investigate proportioning RAP concrete mixtures to achieve desired performance criteria. Based on the results of the RSM investigation, two concrete mixtures were selected for further evaluation: a high RAP mix with fine and coarse aggregate replacement rates of 50 and 100 percent respectively, and a "high" strength mix with one half of the RAP used in the high RAP mix. Both mixes met MDT concrete pavement specifications for slump (1.5 inches), air content (6 percent), and 28-day compressive and tensile strengths (3,000 psi and 500 psi, respectively). These two concrete mixtures were subjected to a suite of mechanical and durability tests to evaluate their potential use in Montana roadways. Mechanical properties tested were compressive and tensile strength, elastic modulus, shrinkage, and creep. Durability tests included alkali-silica reactivity, absorption, abrasion, chloride permeability, freeze-thaw resistance, and scaling. Overall, both mixes performed adequately in these mechanical and durability tests, although it is important to note that the inclusion of RAP had an obvious negative impact on nearly every property tested relative to those of control mixes made with 100 percent conventional aggregates.
Download or read book Mechanical Properties of High Strength Portland Cement Concrete with Recycled Asphalt Pavement as a Percent Replacement of Coarse Aggregate written by Andrew Joseph Fellows and published by . This book was released on 2014 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility of Reclaimed Asphalt Pavement as Aggregate in Portland Cement Concrete Pavement written by Bethany Noel Bermel and published by . This book was released on 2011 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Each year, the US highway industry produces over 100 million tons of reclaimed asphalt pavement (RAP) through the rehabilitation and construction of the nation's roads. Using RAP as aggregate in Portland cement concrete pavement (PCCP) is one attractive application for a further use of this recyclable material. Earlier research has demonstrated the feasibility of creating concrete with RAP aggregate; however, prior studies focus on mechanical properties of the material. This research project will further distinguish the properties of this material and draw conclusions on the concrete's aptness for use as a pavement in Montana. This thesis encompasses the development of candidate RAP in PCCP mixtures that will subsequently move forward for a more thorough evaluation of their material properties. The mixing experiment and preliminary testing phases of this project provided information to draw a number of conclusions about the appropriateness of RAP aggregate in PCCP, including: (1) using conventional practices, PCCP containing RAP aggregate (20 percent fine and 45 percent coarse) can achieve compressive strengths in excess of 3,000-psi; (2) as the RAP replacement rate is increased, the compressive strength of the concrete decreases; (3) fine RAP aggregate appears to have a more detrimental effect on the concrete than coarse aggregate; (4) concretes with a relatively high RAP replacement rate (50 percent fine and 100 percent coarse) may be suitable for transportation applications; (5) at high RAP replacement rates, there appears to be a benefit (relative to concrete strength) in using increased replacements of both fine and coarse RAP, rather than singly replacing just one aggregate gradation; and (6) concrete containing RAP displays increased flexural strengths as compared to traditional PCCP. This material research was performed using a Design of Experiments (DOE) method. The suitability of this statistical method as a mix design development tool was characterized through several important findings, which include: (1) the DOE method was effective in distinguishing mixture behaviors; (2) mix design optimization is readily accomplished using the statistical model generated from the DOE data; and (3) variability in the concrete mixing and testing processes has a significant effect on the capabilities of the statistical model.
Download or read book Feasibility of Reclaimed Asphalt Pavement as Aggregate in Portland Cement Concrete Pavements written by and published by . This book was released on 2015 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was focused on evaluating the feasibility of using minimally processed reclaimed asphalt pavement (RAP) as aggregate replacement in concrete pavements. An initial phase of research demonstrated that concretes with up to 50 percent of the fine aggregates and 100 percent of the coarse aggregates replaced with RAP were suitable for concrete pavement. However, the field performance of these mixes was not evaluated. Further, these initial mixes contained a significant proportion of cement in order to achieve the desired performance criteria, hindering the economic benefit of using this recycled material in concrete. Therefore, the research discussed herein focused on: (1) evaluating the field performance of RAP concrete through a field demonstration project, and (2) reducing the amount of cement required in the RAP concrete by including water-reducing admixtures. As part of the field demonstration project, two RAP-concrete slabs were cast on a roadway near Lewistown, MT, and monitored for damage, shrinkage, and curling over a two-year period. There were no logistical issues associated with the construction of the slabs, and no damage and only minor shrinkage/curling was observed. In regards to the mixture optimization, two modified mix designs with reduced cement contents were developed, and evaluated with a suite of mechanical and durability tests. Mechanical properties tested were compressive and tensile strength, elastic modulus, and shrinkage. Durability tests included abrasion, chloride permeability, freeze-thaw resistance, and scaling. These mixes performed well with respect to all tests, with the exception of the chloride permeability. Although both mixes performed well, the resulting mixes were lean and were difficult to get good consolidation. Moreover, the process for batching these mixes may be considered a hindrance, as it involved slump adjusting the mixes with the water-reducing admixture. This was required because the nature of the RAP aggregates made it difficult to adjust mixes for variations in moisture content.
Download or read book Standard Practice for Pavement Recyling written by and published by . This book was released on 1988 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Mix Design on the Design of the Pavement Structure when Utilizing Recycled Portland Cement Concrete as Aggregate written by James Stanley Fergus and published by . This book was released on 1980 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sustainable Concrete Pavements written by and published by . This book was released on 2012 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed as a more detailed follow-up to a 2009 briefing document, Building Sustainable Pavement with Concrete, this guide provides a clear, concise, and cohesive discussion of pavement sustainability concepts and of recommended practices for maximizing the sustainability of concrete pavements. The intended audience includes decision makers and practitioners in both owner-agencies and supply, manufacturing, consulting, and contractor businesses. Readers will find individual chapters with the most recent technical information and best practices related to concrete pavement design, materials, construction, use/operations, renewal, and recycling. In addition, they will find chapters addressing issues specific to pavement sustainability in the urban environment and to the evaluation of pavement sustainability. Development of this guide satisfies a critical need identified in the Sustainability Track (Track 12) of the Long-Term Plan for Concrete Pavement Research and Technology (CP Road Map). The CP Road Map is a national research plan jointly developed by the concrete pavement stakeholder community, including Federal Highway Administration, academic institutions, state departments of transportation, and concrete pavement-related industries. It outlines 12 tracks of priority research needs related to concrete pavements. CP Road Map publications and other operations support services are provided by the National Concrete Pavement Technology Center at Iowa State University. For details about the CP Road Map, see www.cproadmap.org/index.cfm.
Download or read book Recycling of Portland Cement Concrete Pavements written by William A. Yrjanson and published by . This book was released on 1989 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis will be of interest to pavement designers, construction engineers, and others interested in economical methods for recontstructing portland cement concrete (PCC) pavements. Information is provided on the processes and procedures used by a number of states in using PCC pavement as aggregate in reconstructed concrete pavement. Since 1975 a number of state highway agencies have reconstructed concrete pavements using the old PCC as aggregate in the new pavement. This report of the Transportation Research Board describes the processes used on various projects in several states, giving details of construction procedures, as well as test results on various properties of the recycled aggregates and the resultant concrete.
Download or read book Aggregates in Concrete written by Mark Alexander and published by CRC Press. This book was released on 2005-09-01 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bringing together in one volume the latest research and information, this book provides a detailed guide to the selection and use of aggregates in concrete. After an introduction defining the purpose and role of aggregates in concrete, the authors present an overview of aggregate sources and production techniques, followed by a detailed study of their physical, mechanical and chemical properties. This knowledge is then applied to the use of aggregates in both plastic and hardened concretes, and in the overall mix design. Special aggregates and their applications are discussed in detail, as are the current main specifications, standards and tests.
Download or read book Utilization of Recycled Coarse Aggregates to Develop High Strength Concrete written by Sufiyanu O. Momoh and published by . This book was released on 2017 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of recycled coarse concrete aggregates (RCA) for the construction of road and other non-structural concrete has become a common practice these days. With the increasing demand of concrete, there has been an increase in the demand of natural coarse aggregate (NCA), which has sparked the research on the use of recycled coarse aggregate in structural concrete as an alternative sustainable solution. The objective of this study was to produce high strength concrete using recycled coarse aggregates. ACI 211.4R-5 (1998) suggests that concrete yielding compressive strength of over 6000 psi at 28 days of curing can be considered as high strength concrete. Therefore, various concrete mixes containing different amounts of RCA were tested to determine the optimum replacement of NCA with RCA to obtain the targeted compressive strength of 6000 psi at 28 days of curing. The study was divided into two phases. During the first phase, the effect of using recycled coarse aggregate (RCA) and pozzolan such as micro silica fume (MSF) to make high strength concrete was investigated. Due to inconsistent results from this phase of the study, the second phase of the study consisted of reinvestigating the effect of using recycled coarse aggregate (RCA) to make high strength concrete without micro silica fume by narrowly following the recommendations of ACI 211.4R-5 (1998). In addition, Part 2 of this phase consisted of evaluating the effect of the quantity of cement on the compressive strength of RCA concrete compared to the concrete mixes prepared using 100% NCA. This goal of this part of the study was to determine if there is an optimum amount of cement beyond which the strength gain is minimal. In the first phase of this study, five concrete mixes consisting of 0%, 25%, 50%, 75%, and 100% replacement (by volume) of natural coarse aggregates with recycled concrete coarse aggregates were made using a targeted water to cement (w/c) ratio of 0.4. These mixes were tested after curing periods of 7, 14, and 28 days for compressive strength and after a curing period of 28 days for splitting tensile strength. Also, five additional mixes were prepared and tested using the same mix proportions but using micro silica fume to replace 25% of the portland cement. The results presented show that the addition of micro silica fume (MSF) in all the mixes increases the compressive and tensile strength of the concrete mixes. However, trends of the results from this phase of the study were inconsistent with those available in published literature.. Further scrutiny of the results revealed that the quantity of cement and water used in these mixes were not sufficient for the quantity of aggregates used in the mix designs, thereby, resulting in dry concrete mixes with low slumps causing ambiguities in the results. Therefore, the second phase of the study was initiated which also consisted of two parts. The first part (Part 1) of this phase involved studying the effects of recycled coarse aggregates in concrete, as was done in Phase 1, but the mixes were designed based on the ACI 211.4R-5 (1998) recommendation. Published literature and results from this study show that the recycled coarse aggregates have substantially higher loss of material when subjected to wearing conditions, probably due to weaker cement paste layer and sand particles loosely sticking at the surface. Therefore, during Part 2 of Phase 2 of the study, various quantities of cement i.e., 650 lbs./yd3, 675 lbs./yd3, 700 lbs./yd3 and 725 lbs./yd 3 were used in concrete mixes consisting of 100% RCA and 100% NCA in an effort to determine the optimum amount of cement beyond which there is minimal increase in the compressive strength of concrete made with 100% RCA. The results presented show that as the quantity of cement increases, the strength of the concrete made out of both, the natural and the recycled coarse aggregates increases. It is also observed that while the improvement in strength of the concrete made with 100% natural coarse aggregate increases consistently at about 6% for every additional 25 lbs/yd3 of cement, the rate of increase in the compressive strength of concrete made out of recycled coarse aggregates gradually decreases.
Download or read book Evaluation of Cement and Fly Ash Treated Recycled Asphalt Pavement and Aggregates for Base Construction written by Tyson David Rupnow and published by . This book was released on 2011 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTION: Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base materials, temporary haul roads, and, in the case of RAP, hot mix asphalt construction. Several states currently allow the use of RAP combined with cement for a stabilized base course under both asphalt and concrete pavements. Currently, there is disagreement on what properties are required and how to test the cement and fly ash treated RAP for both asphalt and concrete pavement structures. This project investigated cement and fly ash treated RAP and other materials to determine their suitability for base course construction. OBJECTIVE: The objective of this research was to determine feasibility of cement and fly ash treated RAP and other aggregates as a structural layer for both portland cement concrete and hot mix asphalt pavement systems.
Download or read book Portland Cement Concrete Recycling written by R. Gordon McKeen and published by . This book was released on 1982 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The review of current technology pertaining to the recycling of existing portland cement concrete pavements was conducted. The purpose was to assess the applicability of recycling to U.S. Air Force pavement rehabilitation work. Costs of alternatives were reduced to simple models for use in evaluating sensitivity to cost factors. A study of projects on which this technology was used identified aggregate cost and haul distance as key factors.
Download or read book Recycled Concrete Aggregate written by James Trevor Smith and published by . This book was released on 2009 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Virgin aggregate is being used faster than it is being made available creating a foreseeable shortage in the future. Despite this trend, the availability of demolished concrete for use as recycled concrete aggregate (RCA) is increasing. Using this waste concrete as RCA conserves virgin aggregate, reduces the impact on landfills, decreases energy consumption and can provide cost savings. However, there are still many unanswered questions on the beneficial use of RCA in concrete pavements. This research addresses the many technical and cost-effective concerns regarding the use of RCA in concrete pavements by identifying concrete mixture and proportioning designs suitable for jointed plain concrete pavements; constructing test sections using varying amounts of RCA; monitoring performance through testing, condition surveys and sensor data; modeling RCA pavement performance; and predicting life cycle costs. The research was carried out as a partnership between the Centre for Pavement and Transportation Technology (CPATT) at the University of Waterloo, the Cement Association of Canada, Dufferin Construction, and the Natural Sciences and Engineering Research Council of Canada.rgin aggregate increase as the sources becomes depleted. Multivariable sensitivity analysis showed that the LCCA results were sensitive to construction costs, discount rate, and maintenance and rehabilitation quantities.
Download or read book Recycling of Bituminous Pavements written by Leonard Eugene Wood and published by ASTM International. This book was released on 1978 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Recycled Asphaltic Concrete written by Charles S. Hughes and published by . This book was released on 1977 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a project in which approximately 6,200 tons (5,630 Mg) of asphaltic concrete were recycled through a conventional asphalt batch plant. During the construction of the project, a buildup of asphalt-coated fines occurred in the dryer and the dust collector. The buildup is thought to have been associated with the fineness and/or the high asphalt content of the recycled mix. To solve the problem, a change was made in the recycling process. The project was completed using a heat transfer method with mix proportions as high as 50% recycled material added to 50% virgin aggregate.
Download or read book Recycled Aggregate in Concrete written by Jorge de Brito and published by Springer Science & Business Media. This book was released on 2012-11-28 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
