Download or read book Behavior of Recycled Asphalt Pavement and Recycled Concrete Aggregate as Unbound Road Base written by Ozlem Bozyurt and published by . This book was released on 2011 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Freeze Thaw Effects on Stiffness of Unbound Recycled Road Base written by James M. Tinjum and published by . This book was released on 2013 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major concern for using recycled pavement material as an unbound base or subbase layer is the effect of changing seasons on the properties of the recycled material. Three sources of recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP), and one conventional base aggregate, were used to investigate the effect of freeze-thaw cycles on the stiffness of unbound road base/subbase layers. Effects of freeze-thaw cycling on the mechanical behavior of three gradations (coarse, medium, fine) of recycled materials were systematically evaluated to determine how climatic factors and aging affect the resilient modulus. Sealed specimens were exposed to 5, 10, and 20 sets of freeze-thaw cycles. Resilient modulus tests were conducted according to NCHRP 1-28A after the final freeze-thaw cycle. Freeze-thaw cycling caused a decrease in the stiffness (i.e., the summary resilient modulus) of RAP samples and class 5 aggregate because of the effect of the water retained in the pores. An increase in the stiffness of RCA was observed over 20 freeze-thaw cycles and is attributed to self-cementitious behavior of crushed concrete. Seismic modulus testing was used to investigate the continuous rate of change (daily) of the stiffness for RCA and class 5 aggregate. The seismic modulus test confirmed the trends observed in resilient modulus testing and served as a non-destructive method for tracking changes in stiffness over time and freeze-thaw cycling.
Download or read book Significant Findings from Full scale Accelerated Pavement Testing written by Wynand JvdM. Steyn and published by Transportation Research Board. This book was released on 2012 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 433: Significant Findings from Full-Scale Accelerated Pavement Testing documents and summarizes significant findings from the various experimental activities associated with full-scale accelerated pavement testing (f-sAPT) programs that have taken place between 2000 and 2011. The report also identifies gaps in knowledge related to f-sAPT and where future research may be needed. NCHRP Synthesis 433 is designed to expand the f-sAPT base of knowledge documented in NCHRP Syntheses 325 and 235, both with the same title of Significant Findings from Full-Scale Accelerated Pavement Testing. f-sAPT is the controlled application of a wheel loading, at or above the appropriate legal load limit, to a pavement system to determine pavement response in a compressed time period. The acceleration of damage is achieved by one or more of the following factors: increased repetitions, modified loading conditions, imposed climatic conditions, and thinner pavements with a decreased structural capacity which have shorter design lives"--
Download or read book Recycled Unbound Materials written by Tuncer B. Edil and published by . This book was released on 2012 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project was to characterize the properties of crushed recycled concrete (RCA) and asphalt pavement (RAP) as unbound base without being stabilized, to assess how RCA and RAP behave in the field and to determine how pavements can be designed using RCA and RAP. Issues to be considered include variability in material properties, purity of material, climatic effects, how to identify and control material quality, and leaching characteristics. This project included laboratory specimen and large-scale model tests and evaluation of field data from MnROAD test sections constructed using recycled materials. To identify the characteristics of RAP and RCA typically available in different parts of the country, samples were obtained from eight states: California, Colorado, Michigan, Minnesota, New Jersey, Ohio, Texas, and Wisconsin covering a geographically diverse area. A conventional base course was used as a control material. The extensive investigation undertaken on RCA and RAP indicate that these materials are generally suitable for unbound base course applications and they show equal or superior performance characteristics compared to natural aggregates in terms of stiffness, freeze-thaw and wet-dry durability, and toughness. Their typical compositional and mechanical properties and their variability are defined in this study providing a basis for design considerations. Their relative differences from natural aggregate such as temperature sensitivity, plastic deformations, and water absorption and retention characteristics are also well established. It is noted that some RAP may be sensitive to temperature change that may lead to rutting. This aspect needs to be considered in design.
Download or read book Assessment of Recycled Aggregates for Use in Unbound Subbase of Highway Pavement written by Vahid Ayan and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Intendancy for sustainability has made it necessary for the highways industry to adapt its traditional processes to more cost-effective, energy efficient and greener technologies. This research programme was developed with a key aim of investigating the technical viability of aggregates formed with different combinations of Recycled Concrete Aggregate (RCA), Reclaimed Asphalt Pavement (RAP) and Natural Aggregates (NA) when used in construction of unbound subbases of highway pavements. As strongly evident from a comprehensive literature review carried out, little information is available on the application of RCA and RCA/RAP as subbase materials. The suitability of RCA blended with RAP and NA were investigated and compared to the British Standards, Highway Agency specifications and the AASHTO standards requirements for highway design. Having established their suitability for highway design, then the performance of the materials was assessed under traffic loading. In compliance with the requirements of the above Standards/Specifications the in-situ loaded behavior of the aforementioned materials were also investigated. This was achieved through numerical analysis of a typical pavement structures comprising subbases made of the above materials. As a consequence, a series of analyses were carried out using KENLAYER TM computer program to model the stresses and deformations in the subbases. The results of the analyses were then applied to the Mohr Coulomb failure model in order to predict the factor of safety against failure of the subbase layer. Amongst the salient findings from the research was that most of the materials tested complied with the standard requirements. From a large number of tests carried out on materials collected in the UK and Iran, it was also demonstrated that the source of a recycled material and the method of extraction had a significant influence on the engineering properties of the material, especially the CBR. In terms of compaction and CBR requirements, the 50%RAP+50%RCA mix was demonstrated as suitable for unbound subbase application. Also, the presence of RAP in the mixes of RAP/RCA was found to improve the drainage properties of an unbound subbase layer. From the viewpoint of durability and frost susceptibility, it was verified that all the materials investigated were applicable to the highest significance level (as defined by AASHTO). However, based on stiffness considerations, the materials were found to be applicable only to the lowest significance level. Now, turning to the toughness and shear strength properties, the same materials were found to fall in the middle significance levels. The results of KENLAYER TM modeling indicated that the safety factor against failure of the mixes containing RAP and RCA decreased as the stiffness decreased. Evidently the research is likely to have a number of implications on the design and construction of highways. Firstly, the demonstrated viability of mixes containing recycled materials (RCA+RAP) can lead to significant cost savings, reduced CO2 emissions, reduced exploitation of virgin materials and minimization of dumping of civil engineering waste. If embraced in industry, the suggested use of recycled materials can help support National and international targets regarding sustainability, environmental and energy conservation. The research succeeded in cataloguing the specifications of RCA/RAP and RCA/NA for practical works, followed by development and evaluation of different mixes of recycled aggregates obtained from different sources. Detailed assessment based on compliance with requirements, performance prediction and modeling was completed.
Download or read book Evaluation of Reclaimed Asphalt Pavement and Recycled Concrete Aggregate as a Dense Graded Aggregate Base Course written by Robert Fredwin Baker and published by . This book was released on 1999 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Properties of Recycled Pavement Aggregates and Effect of Soil Suction on Resilient Modulus for Pavement Design written by and published by . This book was released on 2014 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The successful incorporation of recycled aggregates in pavement design is important for achieving a higher level of sustainability in our transportation network. However, recycled aggregates are non-soil materials and have different unsaturated hydraulic and resilient modulus characteristics. This study investigated the unsaturated hydraulic properties and impact of soil suction on resilient modulus for compacted recycled aggregates used as unbound base course, including recycled asphalt pavement (RAP), recycled concrete aggregate (RCA), and recycled pavement material (RPM). Hydraulic properties and relationships including the soil-water characteristic curve (SWCC) and saturated and unsaturated hydraulic conductivity were characterized using a hanging column test coupled with a large-scale testing cell. Regression of the hydraulic parameters from SWCC and unsaturated hydraulic conductivity; data for each type of recycled materials was completed. The effect of water repellency on hydraulic properties was evaluated. Development of testing equipment and procedures that incorporate the effect of soil suction during resilient modulus measurement is presented. A mathematical model to predict resilient modulus based on bulk stress, octahedral shear stress, and soil suction is proposed. In addition, empirical relationships for predicting summary resilient modulus (SRM) via soil suction and SRM at optimum compaction for recycled aggregates are presented. Measured SRM and SWCCs for different types of recycled aggregate were used to evaluate flexible pavement performance according to the approach outlined in the Mechanistic-Empirical Pavement Design Guide (M-EPDG). The impact of environmental effects (including freeze-thaw cycles and changes in temperature) on the resilient modulus of recycled aggregates and subsequent pavement performance are evaluated and presented in this dissertation.
Download or read book Proceedings of the 4th Congr s International de G otechnique Ouvrages Structures written by Hoang-Hung Tran-Nguyen and published by Springer. This book was released on 2017-10-20 with total page 1181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume for the 4th international conference CIGOS 2017 (Congrès International de Géotechnique - Ouvrages - Structures) presents novel technologies, solutions and research advances, making it an excellent guide in civil engineering for researchers, students, and professional engineers alike. Since 2010, CIGOS has become a vital forum for international scientific exchange on civil engineering. It aims to promote beneficial economic partnerships and technology exchanges between enterprises, worldwide institutions and universities. Following the success of the last three CIGOS conferences (2010, 2013 and 2015), the 4th conference was held at Ho Chi Minh City University of Technology, Ho Chi Minh City (Saigon), Vietnam on 26 to 27 October 2017. The main scientific themes of CIGOS 2017 were focused on ‘New Challenges in Civil Engineering’.
Download or read book Cold recycled Bituminous Concrete Using Bituminous Materials written by Jon A. Epps and published by Transportation Research Board. This book was released on 1990 with total page 116 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 reconstructing or rehabilitating bituminous pavements. Information is provided on the processes and procedures used by a number of states to recycle asphalt pavements in place without application of heat. Since 1975 a growing number of state highway agencies have reconstructed or rehabilitated asphalt pavements by recycling the old pavement in place. This report of the Transportation Research Board describes the processes used for cold in-place recycling, including construction procedures, mix designs, mixture properties, performance, and specifications.
Download or read book Recycled Materials and by Products in Highway Applications written by Mary Stroup-Gardiner and published by Transportation Research Board. This book was released on 2013 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycled materials and industrial byproducts are being used in transportation applications with increasing frequency. There is a growing body of experience showing that these materials work well in highway applications. This study gathers the experiences of transportation agencies in determining the relevant properties of recycled materials and industrial byproducts and the beneficial use for highway applications. Information for this study was acquired through a literature review, and surveys and interviews with state department of transportation staff. The report will serve as a guide to states revising the provisions of their materials specifications to incorporate the use of recycled materials and industrial byproducts, and should, thereby, assist producers and users in leveling the playing field for a wide range of dissimilar materials.
Download or read book Use of Recycled Aggregate Materials Characteristics in Pavement Design Analyses written by Ida Gheibi and published by . This book was released on 2020 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Eleventh International Conference on the Bearing Capacity of Roads Railways and Airfields written by Inge Hoff and published by CRC Press. This book was released on 2022-07-07 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: Innovations in Road, Railway and Airfield Bearing Capacity – Volume 3 comprises the third part of contributions to the 11th International Conference on Bearing Capacity of Roads, Railways and Airfields (2022). In anticipation of the event, it unveils state-of-the-art information and research on the latest policies, traffic loading measurements, in-situ measurements and condition surveys, functional testing, deflection measurement evaluation, structural performance prediction for pavements and tracks, new construction and rehabilitation design systems, frost affected areas, drainage and environmental effects, reinforcement, traditional and recycled materials, full scale testing and on case histories of road, railways and airfields. This edited work is intended for a global audience of road, railway and airfield engineers, researchers and consultants, as well as building and maintenance companies looking to further upgrade their practices in the field.
Download or read book Recycled Aggregates written by Ravindra K Dhir and published by ICE Publishing. This book was released on 2019-09-09 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Determining Pavement Design Criteria for Recycled Aggregate Base and Large Stone Subbase written by Bora Cetin and published by . This book was released on 2021 with total page 377 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project was performed to evaluate the performance of recycled aggregates and large stones used in the aggregate base/subbase layers of pavement systems and provide recommendations regarding pavement design and material selection. As part of this project, eleven test cells were built at MnROAD to evaluate the impact of recycled aggregates and large stones on the long-term pavement performance via a series of laboratory [permeability, soil-water characteristic curve (SWCC), stereophotography (image analysis), gyratory compaction, and resilient modulus (MR) tests] and field tests [intelligent compaction (IC), falling weight deflectometer tests (FWD), rutting measurements, international roughness index (IRI) measurements, light weight deflectometer (LWD) tests, and dynamic cone penetrometer (DCP) tests]. In addition, a pavement mechanistic-empirical (ME) design approach was used to provide recommendations for designs of pavement systems containing recycled aggregate base (RAB) and large stone subbase (LSSB) layers. Overall, this project found that finer recycled concrete aggregate (RCA) material would be preferable to coarser RCA material and a blend of RCA and recycled asphalt pavement (RAP) materials would be preferable to natural aggregate for aggregate base layers. RCA materials provided better performance than the blend of RCA and RAP materials, indicating that RCA materials would be preferable to the blend. For LSSB layers, this project found that geosynthetics would be required to successfully construct thinner LSSB layers. Overall, thicker LSSB layers provided better structural support than thinner LSSB layers both in the short term and the long term.
Download or read book Unbound Aggregates in Roads written by R.H. Jones and published by Butterworth-Heinemann. This book was released on 2016-04-20 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unbound Aggregates in Roads contains the proceedings of the International Symposium on Unbound Aggregates in Roads (UNBAR3) held at the University of Nottingham, England, on April 11-13, 1989. The papers focus on unbound aggregates used in road construction and cover topics ranging from drainage and permeability to placement and compaction of unbound aggregates, design philosophy, specification, and compliance. This book consists of 49 chapters divided into eight sections and opens with an overview of the functions of unbound aggregates in roads, followed by a discussion on the mechanical properties of different aggregates and theoretical aspects of granular materials. The following chapters focus on granular drainage layers in pavement foundations; residual stresses caused by compaction in granular materials; and alternative materials for road construction such as steel slags and natural and waste materials. The use of unbound road aggregates in various countries such as Italy, France, Germany, and Portugal is also considered. This monograph will be a useful resource for designers, aggregate producers, contractors, specification writers, and materials engineers.
Download or read book Bituminous Mixtures and Pavements VII written by A.F. Nikolaides and published by CRC Press. This book was released on 2019-05-24 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highway engineers are facing the challenge not only to design and construct sustainable and safe pavements properly and economically. This implies a thorough understanding of materials behaviour, their appropriate use in the continuously changing environment, and implementation of constantly improved technologies and methodologies. Bituminous Mixtures and Pavements VII contains more than 100 contributions that were presented at the 7th International Conference ‘Bituminous Mixtures and Pavements’ (7ICONFBMP, Thessaloniki, Greece 12-14 June 2019). The papers cover a wide range of topics: - Bituminous binders - Aggregates, unbound layers and subgrade - Bituminous mixtures (Hot, Warm and Cold) - Pavements (Design, Construction, Maintenance, Sustainability, Energy and environment consideration) - Pavement management - Pavement recycling - Geosynthetics - Pavement assessment, surface characteristics and safety - Posters Bituminous Mixtures and Pavements VII reflects recent advances in highway materials technology and pavement engineering, and will be of interest to academics and professionals interested or involved in these areas.
Download or read book ICSBE 2022 written by Ranjith Dissanayake and published by Springer Nature. This book was released on 2023-08-09 with total page 867 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the latest knowledge and innovations in the fields of civil engineering and construction industry striving for a sustainable built environment. It consists of high quality and innovative research findings selected from the proceedings of the 13th ICSBE 2022 under the themes of sustainable construction, urban green infrastructure and planning, rainwater harvesting and water conservation, high-performance concrete, indoor environmental quality and indoor plants, wind and hydro-power energy, waste and wastewater management for enhanced sustainability, impacts of climate change, carbon footprint, global climate model and landscaping, material flows and industrial ecology, sustainable materials, etc.
