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Feasibility Of The Use Of Existing Analytical Models And Experimental Data To Assess Current Design Methods For Pavement Geogrid Reinforced Base Layers
Download Feasibility Of The Use Of Existing Analytical Models And Experimental Data To Assess Current Design Methods For Pavement Geogrid Reinforced Base Layers full books in PDF, epub, and Kindle. Read online Feasibility Of The Use Of Existing Analytical Models And Experimental Data To Assess Current Design Methods For Pavement Geogrid Reinforced Base Layers ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Feasibility of the Use of Existing Analytical Models and Experimental Data to Assess Current Design Methods for Pavement Geogrid-reinforced Base Layers by : Steven W. Perkins
Download or read book Feasibility of the Use of Existing Analytical Models and Experimental Data to Assess Current Design Methods for Pavement Geogrid-reinforced Base Layers written by Steven W. Perkins and published by . This book was released on 1995 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years polymer geogrids have been proposed and used to improve the performance of paved roadways and/or to reduce base course thickness. Performance improvements have been demonstrated for design conditions where relatively large rut depths are acceptable and where relatively weak pavement sections have been used. This work was undertaken to examine existing literature concerning laboratory and field experimental studies, and analytical studies pertaining to the inclusion of geogrid polymer materials in roadway pavement sections for the purpose of improving performance or to allow for a reduction in the constructed section thicknesses. The original goal of this study was to examine the feasibility of using existing data from laboratory or field studies and existing finite element models to validate and calibrate the model and then use the model to predict the response of pavement sections not included in the experimental studies. This study has indicated that this approach is feasible and has been accomplished by a previous project. Furthermore, the literature reviewed in this study has shown conflicting results pertaining to the level of improvement that is realized by inclusion of a geogrid in the base course layer of a pavement section. While additional laboratory and analytical studies may aid in resolving these conflicts it is concluded that the most productive approach at this point is to construct well instrumented, full scale field sections to assess improvement levels. These sections should be designed and constructed to include variables identified in previous studies as having the greatest impact on pavement performance.
Book Synopsis Government Reports Announcements & Index by :
Download or read book Government Reports Announcements & Index written by and published by . This book was released on 1995 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Utilization of Geocell-reinforced RAP Material Base Layer in Flexible Pavements by : Anu Muthumala George
Download or read book Utilization of Geocell-reinforced RAP Material Base Layer in Flexible Pavements written by Anu Muthumala George and published by . This book was released on 2019 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reclaimed asphalt pavement (RAP) materials have been considered as one of the most sustainable and cost-effective options in the pavement industry. The use of RAP materials in pavement construction reduces natural resources depletion and the volume of construction debris discarded into the landfills. However, the low shear strength and high permanent deformation (PD) of RAP materials often limit their application in road bases. Utilization of mechanical stabilizers, such as geocell, for stabilizing RAP bases, have found to be effective in improving the pavement performance. The main objective of this study is to assess the efficacy of high-density polyethylene (HDPE) geocell reinforcements in enhancing the strength and stiffness properties of RAP bases and for mitigating PD behavior. In this dissertation research, several large-scale static and repeated load tests were performed on the unreinforced RAP base (URB) and geocell-reinforced RAP bases (GRRB) over clay subgrade. The performance of the geocell reinforcement was evaluated based on various parameters including bearing capacity (q), elastic deformation (ED), PD, resilient modulus (Mr), traffic benefit ratio (TBR), and rut depth reduction (RDR). Test results showed that the HDPE geocell layer increased the Mr and reduced the PD of the RAP base layer when compared to URB. Numerical models of the GRRB sections were developed to assess the load transfer mechanism of geocell reinforcement under static and dynamic loading. These models were developed in FLAC3D (special character) software by employing finite-difference (FD) approach. The unreinforced and reinforced FD models were validated with experimental results and a good agreement between both was observed. The validated FD model was then used to perform parametric studies to assess the factors affecting the performance of geocell-reinforced bases. Additionally, a life-cycle assessment (LCA) and life-cycle cost analysis (LCCA) were performed to estimate the current and future cost of the pavement section with GRRB. This analysis considered agency, user, environmental, and health impact costs incurred during the service life of the pavement section. Finally, an LCA-LCCA framework was developed to assess the sustainability of the pavement infrastructure using a sustainability index. The results showed that the GRRB can be successfully used as a sustainable and cost-effective replacement for virgin aggregate bases. The findings from this research would aid in the development of design charts for assessing the response of geocell-reinforced pavement bases under static and repeated loading.
Book Synopsis Effectiveness of Geotextiles/geogrids in Roadway Construction; Determine a Granular Equivalent (GE) Factor by : Hossein Alimohammdi
Download or read book Effectiveness of Geotextiles/geogrids in Roadway Construction; Determine a Granular Equivalent (GE) Factor written by Hossein Alimohammdi and published by . This book was released on 2021 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geogrids have been widely used in roadway construction as reinforcement in pavement foundations. Geogrids have been effective in practice for reducing rutting damage, distributing traffic loads within the pavement foundation layers, increasing the resilient modulus of the base course, and stabilizing the subgrade layer. For this project, an integrated mobile accelerated test system (IMAS), an automated plate load test (APLT) device, and finite element simulation approaches were used to evaluate the effects of geogrid reinforcement. Test configurations were constructed by varying geogrid types (i.e., light-duty biaxial, heavy-duty biaxial, light-duty triaxial, and heavy-duty triaxial), geogrid locations in the base course (i.e., at the interface between the base and the subgrade or in the base course), and base aggregate thicknesses (6, 10, and 16 in) in the laboratory and in experimental field tests. The finite element method (FEM) models were calibrated based on the results from the experimental test sections. Then, the calibrated FEM models were used to determine granular equivalent (GE) values for the remaining sections. Testing results included resilient modulus, deflection, and permanent deformation of the pavement foundation to evaluate the structural benefits of geogrids as a function of the GE. The results of this research revealed that improvement in pavement performance using geosynthetic reinforcement depended on various factors and variables. A new formulation was proposed to predict the GE factor of geogrid reinforcement of flexible pavements. The products produced by this research include this report, which improves geogrid understanding, and a well-developed method to apply GE factors during pavement design. It is expected that one or more of the following benefits will be achieved during implementation: increased service life, reduced gravel and/or asphalt thickness, and reduced maintenance costs.
Book Synopsis Quality Assessment of Geogrids Used for Subgrade Treatment by : Min Sang Lee
Download or read book Quality Assessment of Geogrids Used for Subgrade Treatment written by Min Sang Lee and published by Purdue University Press. This book was released on 2012-12-31 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geogrid reinforcements have been used by the Indiana Department of Transportation (INDOT) to construct stable subgrade foundations and to provide a working platform for construction over weak and soft soils. Use of geogrid reinforcement in a pavement system ensures a long-lasting pavement structure by reducing excessive deformation and cracking. The main objectives of this research were to evaluate the mechanical interaction between a subgrade soil and an aggregate base layer with and without a geogrid in place at the interface. A series of large-scale direct shear tests were performed to investigate the effects of geogrid properties, such as geogrid aperture area, junction strength, and tensile strength, on the interface shear strength of soil-geogrid-aggregate systems. The test results showed that the aperture size and junction strength of the geogrids were relatively important factors affecting the overall interface shear strength the most. The average values for the peak interface shear strength coefficient for the three normal stresses (50 kPa, 100 kPa and 200 kPa) considered in this study ranged from 0.96 to 1.48. In addition, the test results showed that the average peak interface shear strength coefficient increases with increases in the junction strength of the geogrid. The optimum aperture area of the geogrid was found to be equal to 825 mm2 (1.4 in2) for the subgrade soil and aggregate considered in this study. There was no significant correlation between the geogrid tensile strength at 2% strain and the average peak interface shear strength coefficient. The effect of the moisture content of the subgrade soil on the peak interface shear strength coefficient was also investigated. The peak interface shear strength coefficient for the subgrade soil sample prepared at the optimum moisture content and compacted to relative compaction values of 94-96 % (Rsoil = 95-96% and Raggregate = 94-95%) and tested under a normal stress of 100 kPa was 20% less than that for the subgrade soil sample prepared at a moisture content 4% above the optimum moisture content. Based on the results of the tests performed in this study, an aperture area requirement of 825 mm2 (1.4 in2) and a junction strength requirement of 11.5 kN/m (788 lb/ft) were suggested as preliminary guidelines for subgrade reinforcement systems. These requirements are only limited to the use of Type IV geogrid (INDOT specification 207.04) for subgrade reinforcement with aggregate No. 53.
Book Synopsis Evaluation of the Base/subgrade Soil Under Repeated Loading by : Murad Yusuf Abu-Farsakh
Download or read book Evaluation of the Base/subgrade Soil Under Repeated Loading written by Murad Yusuf Abu-Farsakh and published by . This book was released on 2009 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :American Association of State Highway and Transportation Officials Publisher :AASHTO ISBN 13 :156051423X Total Pages :218 pages Book Rating :4.5/5 (65 download)
Book Synopsis Mechanistic-empirical Pavement Design Guide by : American Association of State Highway and Transportation Officials
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:
Book Synopsis Development of a Mechanistic Model for Geogrid Reinforced Flexible Pavements by : Jayhyun Kwon
Download or read book Development of a Mechanistic Model for Geogrid Reinforced Flexible Pavements written by Jayhyun Kwon and published by . This book was released on 2007 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the development of a mechanistic response model for the analysis of geogrid base reinforced flexible pavements and to investigate the response benefit of geogrid-reinforcement. This is an axisymmetric finite element structural model that considers the nonlinear, stress dependent pavement foundation geomaterials, i.e., unbound base aggregates and fine grained subgrade soils, anisotropic behavior of the granular base materials, as well as the compaction and preloading induced residual stresses in the granular base. The mechanistic model was used to investigate geogrid reinforcement mechanisms by considering locked-in horizontal residual stresses formed around the geogrid location for a proper modeling of the stiffening effect shown by the geogrid. These residual stresses are taken as initial conditions in pavement response analysis. To validate the response model, full-scale flexible pavement test sections, geogrid reinforced and unreinforced, were constructed at the University of Illinois Advanced Transportation Research and Engineering Laboratory (ATREL). Results from full-scale tests showed reduced critical pavement responses due to the inclusion of geogrid reinforcement. Higher percent reductions in lateral deflections in the aggregate base were realized especially in the direction of traffic. The anisotropic characterization of the granular base was needed to better capture the measured responses from the full-scale test sections. Field forensic and pavement trench studies were used to further calibrate the mechanistic response model. Typical increased horizontal residual stresses at the level of approximately 41 kPa was also needed 100 mm around the geogrid to better match measured pavement responses of the reinforced sections. As a result of the calibration efforts, the predicted responses at different locations in the test sections compared in general well with the field measured responses under different load levels.
Author :American Association of State Highway and Transportation Officials Publisher :AASHTO ISBN 13 :1560510552 Total Pages :622 pages Book Rating :4.5/5 (65 download)
Book Synopsis AASHTO Guide for Design of Pavement Structures, 1993 by : American Association of State Highway and Transportation Officials
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.
Book Synopsis Analytical, Experimental, and Field Evaluations of Soil-geosynthetic Interaction Under Small Displacements by : Gholam Hossein Roodi
Download or read book Analytical, Experimental, and Field Evaluations of Soil-geosynthetic Interaction Under Small Displacements written by Gholam Hossein Roodi and published by . This book was released on 2016 with total page 1246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing use of geosynthetics in stabilization of pavement systems under traffic loads and environmental changes requires proper understanding of the mechanisms that govern the soil-geosynthetic interaction. Significant research has already been conducted on the soil-geosynthetic interaction under ultimate conditions, which is relevant to reinforcement of retaining walls and steep slopes. However, little research has been undertaken to investigate the properties and mechanisms that govern the soil-geosynthetic interaction under small displacements, which is relevant to applications such as the geosynthetic stabilization of pavement layers. While characterization of the maximum geosynthetic strength (e.g., tensile strength or pullout resistance) is relevant for the design of soil-geosynthetic systems under ultimate conditions, proper design properties in systems where geosynthetics are used to control deformations should involve characterization of the stiffness of soil-geosynthetic composite. The objective of this research is to develop a better understanding of the soil-geosynthetic interaction under small displacements using analytical, experimental, and field evaluations. Three studies were conducted on different aspects of soil-geosynthetic interaction under small displacements: (1) Analytical and experimental evaluations of the soil-geosynthetic composite (SGC) model using large-scale soil-geosynthetic interaction tests, (2) analytical and experimental evaluations of soil-geosynthetic interaction using small-scale soil-geosynthetic interaction tests, and (3) field evaluation of soil-geosynthetic interaction under small displacements. Each study provides lessons and conclusions on specific aspects investigated in that study. Collectively, they suggest that the analytical model proposed in this study provides a good basis towards predicting the general performance of geosynthetic-stabilized pavements. The analytical formulation of the SGC model indicates that soil-geosynthetic interaction under small displacements can be characterized by the stiffness of soil-geosynthetic composite ( ), which is the slope of the linear relationship defined between the unit tension squared (T2) versus displacements (u) in each point along the active length of a geosynthetic. The linearity and uniqueness of the relationship between the unit tension squared (T2) and displacements (u) throughout the active length of specimens tested in a comparatively large soil-geosynthetic interaction device were experimentally confirmed. Overall, the experimental results from the large-scale soil-geosynthetic interaction tests were found to be in good agreement with the adopted constitutive relationships and with the analytical predictions of the SGC model. Evaluation of experimental results from tests conducted to assess repeatability indicated that the variability of the estimated values for the constitutive parameters ( and ) and the stiffness of soil-geosynthetic composite ( ) are well within the acceptable ranges when compared to variations of other soil and geosynthetic properties. Suitability of the assumptions and outcomes of the model was also confirmed for a variety of testing conditions and materials. Evaluation of the experimental data obtained from a subsequent experimental program involving small-scale soil-geosynthetic interaction tests indicates that although the assumptions of the analytical model do not fully conform to the conditions in a small-scale test, experimental results confirm the linearity and uniqueness of the relationship between the unit tension squared (T2) and the displacements (u) throughout the specimen. Evaluation of the results obtained from small- and large-scale interaction tests on five geosynthetics with a range of properties indicates that both large and small testing scales can be used for comparative evaluation of the stiffness of soil-geosynthetic composite among geosynthetics. However, since the stiffness values obtained from the two testing scales were found to be different, the stiffness values from the large-scale soil-geosynthetic interaction tests should be suitable for design purposes, while values from the small-scale interaction tests should be suitable for specification and comparison purposes. Evaluation of the long-term performance of full-scale paved test sections under both traffic and environmental loads indicates that stabilization with geosynthetics contributes to improving the road performance under both loading conditions. The benefits derived from using geosynthetics under traffic loads were realized by reducing the total length of rut or rutting depth. On the other hands, the benefits from using geosynthetics under environmental loads in roads founded on expansive subgrades were realized by mitigating the percentage of longitudinal cracks appears on the road surface. The latter benefits were found to be more pronounced towards the end of dry seasons, when longitudinal cracks tend to develop. Comparison among the performances of geosynthetic-stabilized test sections under environmental loads indicate that the benefit provided by geosynthetics correlates well with the stiffness of soil-geosynthetic composite ( ) characterized in the laboratory. Geosynthetic products with comparatively larger were found to lead to a comparatively better field performance.
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.
Book Synopsis Development of a Test Protocol for Cyclic Pullout of Geosynthetics in Roadway Base Reinforcement by : Timothy Michael Holley
Download or read book Development of a Test Protocol for Cyclic Pullout of Geosynthetics in Roadway Base Reinforcement written by Timothy Michael Holley and published by . This book was released on 2009 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geosynthetics, or manmade materials used in soils engineering, have successfully been used as base reinforcement of pavements for over 40 years. Use of geosynthetics can result in cost savings by allowing the aggregate base layer to be reduced in thickness and/or the service life of the pavement to be extended. Design methods for this type of reinforcement have typically been developed by individual manufacturers for specific products. These methods are not widely used by state transportation agencies because 1) they are proprietary, 2) they are empirically based, and 3) they lack compatibility with the current national trend towards mechanistic-empirical pavement design procedures. This project was initiated to develop testing methods to determine one of the critical material properties needed for mechanistic-empirical base-reinforced pavement design, namely, the resilient interface shear stiffness. This property describes the interaction, in particular the shear stiffness, between the geosynthetic and the surrounding aggregate. This new test protocol closely mimics vehicular load patterns, resulting in design parameters pertinent to the use of the geosynthetics to reinforce the base course. A study was conducted to evaluate the repeatability of these tests and to develop a standardized test method. Specific parameters under investigation include load pulse and rest period duration, embedment length of the geosynthetic, and differences in results using different soils and types of geosynthetics. Some parameters seemed to have little effect on values of resilient interface shear stiffness, while others vastly impacted the results. Load pulse and rest period durations did not affect output results significantly. Maintaining a constant confinement or shear stress during the test duration produced higher repeatability and correlated well to the adapted resilient modulus equation. Three-aperture length tests on polyester geogrid also correlated well with this equation, however repeatability was moderately low. Polypropylene geogrid and a woven geotextile confined in Ottawa sand displayed low correlation to this equation. During testing, very small displacements occur, and therefore, every effort should be made to ensure that these measurements are accurate and not skewed by electrical noise and interference.
Book Synopsis Experimental Study on Resilient Behavior of Geocell-reinforced Recycled Asphalt Pavement Base Layer by : Manikanta Saladhi
Download or read book Experimental Study on Resilient Behavior of Geocell-reinforced Recycled Asphalt Pavement Base Layer written by Manikanta Saladhi and published by . This book was released on 2017 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycled Asphalt Material (RAP) is defined as removed and reprocessed pavement materials containing asphalt and aggregates. These materials are obtained when asphalt pavements are removed for the rehabilitation and maintenance of distressed pavements. The use of RAP as a base/subbase aggregate in pavement construction is technically and environmentally a sustainable solution, and conserve use of natural resources by requiring less virgin aggregate in pavement construction. Past studies showed that the use of 100% RAP as base course lacks shear strength and can undergo large deformations. Geocells are a system of threedimensional, interconnected, honeycombed cellular structures that resist the lateral expansion of soil particles and act like a slab to distribute surface loads over a larger area of the foundation soil. Most of the recent studies on geocell-reinforced RAP bases show that they improve the pavement service life, strength and stiffness of base layer. The main objective of this research was to develop and construct a large-scale laboratory test setup, which was used to perform a series of cyclic plate load tests to examine resilient behavior of geocell-reinforced RAP bases. Six large-scale laboratory cyclic plate load tests and two static plate load tests were conducted on unreinforced and geocell-reinforced RAP base road sections. The unpaved road sections consisted of moderate subgrade, unreinforced/geocell-reinforced RAP base, and a RAP cover. The test results showed that the geocell-reinforcement improved the performance of RAP bases. The high hoop strength of the geocell reinforcement provided more confinement and offered additional resistance against lateral movement of RAP base. The geocell reinforcement significantly reduced the permanent and resilient deformations of RAP base when compared to that of unreinforced RAP bases, thereby increasing resilient modulus of the reinforced base layer. The geocellreinforced RAP base layer acted as a stiff mattress foundation and resulted in lower compression of RAP base and subgrade. The geocell reinforcement significantly reduced the permanent deformations of RAP base approximately by 50% when compared to that of unreinforced RAP base. Additionally, the geocell reinforcement had increased resilient modulus of RAP base by a factor of 3.0, compared to that of unreinforced RAP base.
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Evaluation of Mechanisms Governing the Stabilization of Unbound Aggregate Bases by Geogrids in Flexible Pavements by : Subramanian Sankaranarayanan
Download or read book Evaluation of Mechanisms Governing the Stabilization of Unbound Aggregate Bases by Geogrids in Flexible Pavements written by Subramanian Sankaranarayanan and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The benefits of using geosynthetics to stabilize the unbound aggregate layers in flexible pavements, in terms of improvement to pavement life or potential decrease in layer thickness, have been well documented. Early research focused on developing ratios such as the traffic benefit ratio (TBR) or the layer coefficient ratio (LCR) to quantify (empirically) the benefits of including geogrids, and for their use in the design of flexible pavements with those geogrids. However, the lack of a mechanistic understanding of geogrid-stabilization and the empirical nature of this data limited their use to the geogrids and pavement materials that were used to develop them. With the proliferation of different geogrid products and pavement materials, the scope of the early research has become limited and attempts to correlate the properties of the geogrids and pavement materials to the improvement in performance of the pavement have not been successful. This study aims to further the understanding of the mechanisms involved in geogrid-stabilization and to identify the mechanistically relevant properties that contribute to this stabilization. Accelerated pavement tests are conducted, using the model mobile load simulator (MLS11), on reduced-scale pavement test sections with and without geogrids for stabilization under controlled, laboratory conditions. The performance of the pavement sections is evaluated by monitoring the deformation of the surface, the internal particle displacements (within the base), and the dynamic increase in stress (within the pavement structure) for increasing traffic volume. The deformation of the surface is obtained by profiling the surface of the pavement at regular traffic intervals using a laser profilometer, designed and built in-house for this study. A unique cost-effective displacement measuring technique is developed and implemented to obtain the horizontal displacement data of particles in the base. The data from the dense array of the particle tracking sensors is used to generate the horizontal displacement field, horizontal normal strain field and shear transfer efficiency plots in the base. The vertical stress distribution is obtained from the earth pressure cells installed within the pavement structure that are monitored for dynamic stress responses with applied traffic. The inclusion of the stabilizing geogrid resulted in reduced rut development, reduced particle displacements within the base and a wider distribution of the applied load for similar traffic volumes in the control and stabilized sections. The improvement in pavement life due to the stabilization of the base by the geogrid is quantified as the traffic benefit ratio (TBR). The TBRs are determined for seven different geogrids from the accelerated pavement tests, and correlated with the most commonly used in-isolation properties of the geogrid (geometric and tensile properties), and interaction properties of the geogrid-base aggregate composite. The TBRs are found to be best correlated to the coefficients of soil-geosynthetic composite stiffness (K [subscript SGC]) obtained from the soil-geosynthetic interaction tests
Book Synopsis Concrete Pavement Design, Construction, and Performance by : Norbert Delatte
Download or read book Concrete Pavement Design, Construction, and Performance written by Norbert Delatte and published by CRC Press. This book was released on 2007-09-12 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressing the interactions between the different design and construction variables and techniques this book illustrates best practices for constructing economical, long life concrete pavements. The book proceeds in much the same way as a pavement construction project. First, different alternatives for concrete pavement solutions are outlined. The desired performance and behaviour parameters are identified. Next, appropriate materials are outlined and the most suitable concrete proportions determined. The design can be completed, and then the necessary construction steps for translating the design into a durable facility are carried out. Although the focus reflects highways as the most common application, special features of airport, industrial, and light duty pavements are also addressed. Use is made of modeling and performance tools such as HIPERPAV and LTPP to illustrate behavior and performance, along with some case studies. As concrete pavements are more complex than they seem, and the costs of mistakes or of over-design can be high, this is a valuable book for engineers in both the public and private sectors.
Book Synopsis Performance of Geotextile-reinforced Bases for Paved Roads by : Milad Saghebfar
Download or read book Performance of Geotextile-reinforced Bases for Paved Roads written by Milad Saghebfar and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Geotextiles have been widely promoted for pavement structure over the past 30 years. However, there is a lack of well-instrumented, full-scale experiments to investigate the effect of geotextile reinforcement on the pavement design. In this study, full-scale accelerated tests were conducted on eight lanes of pavement test sections. Six out of these eight sections had granular bases reinforced with different types of woven geotextiles. The reinforced base sections and the control sections (with unreinforced base) were paved with Superpave hot-mix asphalt. Base and subgrade materials were the same for all sections while the test sections had different asphalt and base layer thicknesses. Each section was instrumented with two pressure cells on top of the subgrade, six strain gages on the geotextile body, six H-bar strain gages at the bottom of the asphalt layer, two thermocouples and one Time Domain Reflectometer (TDR) sensor. The sections were loaded to 250,000 to 500,000 repetitions of an 80-kN single axle load of the accelerated pavement testing machine. The mechanistic response of each section was monitored and analyzed at selected number of wheel passes. Results indicate that properly selected and designed geotextile-reinforced bases improve pavement performance in term of rutting and reduced pressure at the top of the subgrade. Finite element (FE) models were developed and verified using results from the full-scale accelerated pavement tests. The calibrated model was used to investigate the effects of geotextile properties on the pavement responses. FE analysis shows that benefits of reinforcement are more evident when stiffer geotextile is used.
