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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 32 for “"Subbase"”.
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Permanent Deformation Behavior of Airport Flexible Pavement Base and Subbase Courses
… pavement test sections in the granular base and subbase layers, designated as NAPTF P209/P154 base and subbase according to FAA's construction specifications. To account for the rutting performances of these substantially thick granular layers, a comprehensive set of repeated load triaxial tests, …
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Investigation of compaction characteristics of subbase material using the superpave gyratory compactor
… including P-154, P-209, and DGA, which are the subbase and base materials used by the FAA at the National Airport Pavement Test Facility (NAPTF). During the past construction cycles at the NAPTF, it has been found that the flexible pavements failed due to excessive compaction of the subbase …
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Estudio de los materiales granulares utilizados en capas de base y subbase en carreteras
l objetivo de esta tesis ha sido el estudio de las características que definen el empleo de las capas granulares en la estructura del firme con el fin de mejorar las cualidades de los materiales que las componen y de diseñar nuevas estructuras de firme adaptadas adecuadamente a las características …
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Development Of Design Equations For A Square-tube Subbase Supporting A Shaft-mounted Speed Reducer
… for transporting ore out of mine shafts. A subbase joins the reducer with an electric motor, and serves to limit the misalignment between the motor shaft and the reducer input shaft. The entire assembly is supported at two points: the axis of rotation of the reducer output shaft, which is …
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Development and application of bender element field sensor for pavement base/subbase modulus characterization and geogrid effectiveness evaluation
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-12-01
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Rapid Soil Stabilization of Soft Clay Soils for Contingency Airfields
… strength and thickness for an underlying subbase layer and a top base layer, such as stabilized soil, crushed-aggregate, or aluminum matting. From laboratory studies, the required design strengths for many loading conditions were achieved by treating clay with 2%-4% pelletized quicklime …
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Metodología para el avance en la caracterización del suelocemento de aplicación en firmes semirrígidos
… que se compacta para su empleo como base o subbase en firmes de carreteras. Esta adición de cemento confiere a la mezcla una mejora en sus propiedades a la vez que aumenta su durabilidad. Para la determinación de su vida útil, el Ministerio de Fomento adopta criterios derivados de los …
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Cement Stabilized Crushed Stone Base Course Strength and Stiffness Analysis
… is calculated from subgrade resilient modulus, subbase modulus of elasticity (MOE), and the subbase depth. The ME instead includes material properties such as MOE and Poisson’s ratio, in addition to a large list of other inputs toprovide a pavement design that can resist required traffic …
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Analyses and prediction of granular layer rutting trends in airport pavements due to heavy aircraft wheel loading and wander patterns
… CC5 sections were built with different subbase materials (crushed quarry screenings and dense graded aggregates) with varying thicknesses over a low-strength subgrade and were trafficked by six-wheel and 10-wheel landing gears with wander. These pavement sections were instrumented with …
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Y-cracking in continuously reinforced concrete pavements
… included the concrete pavement, asphalt concrete subbase, and soil subgrade. The effect of areas of changed friction on the direction of principal stress was simulated by considering a patch at the pavement-subbase interaction. Investigated factors related to this patch were location of patch, …
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Sustainable pavement applications utilizing quarry by-products and recycled/nontraditional aggregate materials
… passing No. 200 sieve) in dense-graded aggregate subbase over soft subgrade soils; (3) using QB as a cement or fly ash-treated subbase (e.g., in inverted pavements); (4) using QB as a cement-treated base material; and (5) for base course applications, blending QB with coarse aggregate fractions of …
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Permanent deformation behavior of unbound granular materials and rutting model development
… rut estimates in unbound aggregate base/subbase layers by discounting the contribution of stress state from the original Tseng and Lytton (1989) model. This research study was aimed at developing a new permanent deformation prediction model that would properly take into account the …
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Influence of subgrade improvement and non-uniformity on pavement performance
… stabilized subgrade, natural subgrade, granular subbase, and hydrated fly ash. The first project shows that self-cementing fly ash stabilization of RAP-soil mixtures is economically feasible and structurally capable of supporting construction traffic. The increase stiffness from the addition of …
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On Cross-Anisotropy of Flexible Pavement Layer Materials for Improved Pavement Responses
… moving vehicles. Unbound layers such as base and subbase are stress-dependent. The stiffness of an unbound layer differs at different months over a year due to varying moisture contents. This study considers all of these factors such as temperature, frequency, and moisture with material …
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Characterization of waste recycled glass as a highway material
… cullet was identified for use in base course, subbase, subgrade and embankments and also for backfill applications. A test program was devised to test the engineering suitability of glass cullet samples for the above mentioned applications. Stripping tests were also done to determine the …
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Moisture Content Determination and Temperature Profile Modeling of Flexible Pavement Structures
… configuration. The moisture content of aggregate subbase layers was measured utilizing two types of Time-Domain Reflectometry (TDR) probes that differed in their mode of operation. The temperature profile of the pavement was measured using thermocouples. Data for the moisture content determination …
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Three-dimensional finite element modeling as a tool for flexible pavement design and analysis
… of stress on the subgrade and adding additional subbase has diminishing returns in improving the pavement performance. The elastic response of the pavement does not supply a good representation of the permanent behavior. When moving wheel loads with wander was considered greater stresses and …
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Investigation of the performance of flexible pavement systems under moving loads using finite element analyses
… The stress-strain response of the base, subbase, and subgrade layers are simulated using an elasto-plastic model and the asphalt layer is modeled separately as a viscoelastic and elasto-plastic material. The entire pavement system is also modeled as layered linear elastic. The data …
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Evaluation of bonded concrete overlays on asphalt pavements
… included concrete, asphalt layer, aggregate subbase and subgrade samples from each project. FWD testing, distress surveys, IRI, and ultrasonic MIRA testing was completed at each project location. First, Falling weight deflectometer (FWD) and MIRA data was collected to determine slab …
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