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 Gravel Roads written by Ken Skorseth and published by . This book was released on 2000 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.
Download or read book Performance Related Tests on Recycled Materials for Sustainable Design of Pavement Systems written by Athar Saeed and published by . This book was released on 2011 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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 Soil Stabilization in Pavement Structures Pavement design and construction considerations written by Terrel, Epps, and Associates and published by . This book was released on 1980 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AASHTO Guide for Design of Pavement Structures 1993 written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1993 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.
Download or read book Geotechnical Properties of Recycled Concrete Aggregate in Pavement Sub Base Applications written by A. Arulrajah and published by . This book was released on 2012 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a laboratory investigation of the geotechnical properties of recycled concrete aggregate (RCA). The properties of RCA were compared with state road authority requirements to assess its performance as a pavement sub-base material. The experimental programme included tests such as particle size distribution, modified Proctor compaction, particle density, water absorption, California bearing ratio (CBR), Los Angeles abrasion loss, pH, organic content, static triaxial, and repeated load triaxial tests. The Los Angeles abrasion loss tests indicated that the RCA is durable. CBR values were found to satisfy the local state road authority requirements for sub-base material. Repeated load triaxial tests established that the RCA would perform satisfactorily as a pavement sub-base material in the field. The results of the laboratory testing undertaken in this research indicated that RCA satisfied the criteria for use in pavement sub-base applications.
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 Advances in Transportation Geotechnics IV written by Erol Tutumluer and published by Springer Nature. This book was released on 2021-08-30 with total page 971 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents selected papers presented during the 4th International Conference on Transportation Geotechnics (ICTG). The papers address the geotechnical challenges in design, construction, maintenance, monitoring, and upgrading of roads, railways, airfields, and harbor facilities and other ground transportation infrastructure with the goal of providing safe, economic, environmental, reliable and sustainable infrastructures. This volume will be of interest to postgraduate students, academics, researchers, and consultants working in the field of civil and transport infrastructure.
Download or read book Superpave Mix Design written by Asphalt Institute and published by . This book was released on 2001-01-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Box Study on Granular Base Options for Portland Cement Concrete Pavements written by Tanya N. Walkenbach and published by . This book was released on 2021 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the depletion of natural resources and limited funding for necessary pavement construction and rehabilitation, recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) are potential alternatives to the virgin granular base (VGB) typically used. The addition of geosynthetics at the interface of base course and subgrade can stabilize base course sections through separation, lateral restraint, and a tensioned membrane effect. This large-scale box study focused on two different granular base options (VGB and RCA) with geosynthetic stabilization for concrete pavement applications. Unpaved road tests under cyclic loading were first conducted on these granular bases over weak subgrade to evaluate the benefits of three types of geosynthetics (nonwoven geotextile, woven geotextile, and triaxial geogrid) and replacement of VGB with RCA in the improved performance (permanent deformation and stress reduction) and properties (resilient modulus and modulus of subgrade reaction). The nonwoven geotextile was selected for three concrete paved roads with VGB and RCA over the same subgrade under cyclic loading. Displacement transducers and earth pressure cells were placed in the test sections to monitor resilient and permanent deformations on the section surface and vertical interface stresses between base course and subgrade. For the unpaved test sections, the measured resilient and permanent deformations and the interface stress reduction were analyzed to evaluate the benefits of geosynthetics and replacement of VGB with RCA. The modified Burmister solution and the stress reduction method were used to back-calculate the resilient moduli (Mr) of the granular bases for all the test sections. Back-calculated resilient moduli were correlated with the accumulated permanent deformations to assess these methods. The American Association of State Highway and Transportation Officials (AASHTO, 1993) design chart was used to estimate the composite subgrade reaction moduli of the unpaved test sections based on the back-calculated resilient moduli (Mr) of the granular bases. The three concrete paved sections and the benefits of the nonwoven geotextile and the replacement of VGB with RCA were evaluated in terms of their total and permanent displacements and base course-subgrade interface stresses. Based on the measured vertical displacements at the loaded corner, Westergaard's (1926) method was used to back-calculate the subgrade reaction moduli of these sections and estimate the tensile stresses in the concrete slabs. The back-calculated subgrade reaction moduli of these concrete paved sections were compared with those calculated based on the unpaved road sections. The key findings of this study are: (1) geosynthetics were effective in reducing the permanent deformations of both VGB and RCA base courses over the weak subgrade in unpaved and concrete paved roads under cyclic loading; (2) RCA was stronger and stiffer than VGB and replacement of VGB with RCA reduced the permanent deformations in unpaved and concrete paved roads under cyclic loading; (3) the resilient modulus of the base course in an unpaved road section back-calculated by the modified Burmister solution with the mechanistic-empirical damage model was correlated well with the accumulated permanent deformation of the unpaved road section; (4) the modulus of subgrade reaction of a base over a subgrade estimated by the AASHTO design chart with the back-calculated resilient modulus of the base from an unpaved road test was similar to that back-calculated by the Westergaard solution based on the displacement at the loaded corner; (5) the accumulated permanent deformation of an unpaved or concrete paved section increased with the reduction of the subgrade reaction modulus in a semi-logarithmic relationship; and (6) geosynthetic stabilization and/or replacement of VGB with RCA increased the resilient modulus and the subgrade reaction modulus of a test section.
Download or read book Paving Materials and Pavement Analysis written by American Society of Civil Engineers and published by Amer Society of Civil Engineers. This book was released on 2010 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pavement Design And Paving Material Selection are important for efficient, cost effective, durable, and safe transportation infrastructure Paving Materials and Pavement Analysis contains 73 papers examining bound and unbound material characterization, modeling, and performance of highway and airfield pavements. The papers in this publication were presented during the GeoShanghal 2010 International Conference held in Shanghai, China, June 3-5, 2010.
Download or read book Mechanistic empirical Pavement Design Guide written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guide for Pavement Friction written by and published by AASHTO. This book was released on 2008 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains guidelines and recommendations for managing and designing for friction on highway pavements. The contents of this report will be of interest to highway materials, construction, pavement management, safety, design, and research engineers, as well as others concerned with the friction and related surface characteristics of highway pavements.
Download or read book Performance of Cement Treated Recycled Aggregates Under Wetting drying Cycles in Pavement Base written by Saif Bin Salah and published by . This book was released on 2017 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resilient Modulus (MR) is one of the most important stiffness parameter to determine the thickness of a pavement layer (AASHTO 2003 pavement design guideline). Recent studies conducted by researchers on the variability of MR with wetting-drying (WD) and freeze-thaw (FT) cycles show that long-term durability is an important criterion to be considered in designing pavement base with recycled materials. At present, the design procedure does not consider the effect of deterioration of pavement layers due to seasonal variations and limited studies have been conducted to evaluate the effect of environmental deterioration on the reclaimed asphalt pavement (RAP) and recycled crushed concrete aggregate (RCCA) mixtures stabilized with cement. The objective of this study is to evaluate the long-term durability of RCCA and RAP mix materials under repeated wetting-drying cycles. Three different combinations of RCCA and RAP materials containing 0%, 30% and 50% RAP content were used in this study. Each of these combinations were then stabilized with 4% and 6% cement content. After curing for 7 days the samples prepared from these material combinations were subjected to 4, 8, 16 and 30 wetting-drying (W-D) cycles. For the purpose of comparison, a different set of samples of the same combinations were prepared, cured for 7 days, and then further cured for 15, 25, 40 and 70 days. Resilient modulus tests were then conducted on all the samples at the end of these specified W-D cycles and curing periods. Environmental tests were also conducted to assess the effect of WD cycles on the washed-out water quality. These tests included total suspended solids (TSS), total dissolved solids (TDS), turbidity, chemical oxygen demand (COD) and pH. MR test results indicated that addition of 50% RAP into the mix reduced the resilient modulus (MR) by about 39%. Increasing the cement content from 4% to 6% increased the MR values by about 20-35% for all material combinations. Higher cement content also resulted in higher durability of the materials containing 30% and 50% of RAP. All the six material combinations used in this study showed adequate strength after 7-days of curing. But the mix containing 30% RAP + 70% RCCA 4% cement (30R_4C) and 50% RAP + 50% RCCA 4% cement (50R_4C) failed to meet the minimum layer coefficient value of 0.13 (AASHTO 2003) for pavement base layer after 8-16 wetting-drying cycles. Results obtained from the environmental tests after 30 WD cycles were found to be within the permissible values provided by EPA guidelines.
Download or read book Recycled Asphalt Pavement as a Base and Sub Base Material written by N. Gucunski and published by . This book was released on 1997 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory and field investigations were conducted to evaluate the use of recycled asphalt pavement (RAP) in roadway base and sub-base applications. The laboratory resilient modulus test results showed RAP has comparable strength with dense graded aggregate base and sub-base material used in the State of New Jersey. Using the spectral-analysis-of-the-surface-waves method (SASW), the field testing program evaluated the elastic modulus of the RAP base in the field and verified the laboratory results. The field test results showed higher modulus and stiffness for RAP than the dense graded aggregate base normally used in state of New Jersey.
Download or read book Aggregate Quality Requirements for Pavements written by E. Tutumluer and published by . This book was released on 2018 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
