Testing procedures and methods of analysis for determining the fracture toughness soils using ring test are described values measured 132 compacted specimens two cohesive presented. The critical mode I stress‐intensity factor, J integral, tensile strength can be determined simultaneously from a single ring‐test specimen. integral was approximately equal to energy‐release rate computed factor same A strong correlation between ring‐specimen found. Effects material type, water content,...

The study presented in this paper analyzed the development patterns of fatigue cracking shown flexible pavement test sections long-term performance (LTPP) program. A large number LTPP exhibited a sudden burst after few years service. In order to characterize type data, survival analysis was conducted investigate relationship between failure time and various influencing factors. After dropping insignificant factors, accelerated models were developed show quantitative asphalt concrete layer...

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Image-based systems are becoming popular to collect pavement condition data for management activities. Pavement engineers define various distress categories based on types. However, software solutions today have limitations in correctly recognizing types from the collected images an automated way. This paper presents a convolutional neural network (CNN)-based PvmtTPNet automatically recognize at acceptable levels of consistency, accuracy, and high-speed. asphalt concrete pavements, jointed...

Achieving proper compaction of asphalt pavement is crucial to its longevity and acceptable performance. Laboratory an essential part mix design. In order for the design process be effective, laboratory must adequately simulate field compaction. This study used mechanical properties measured with Superpave shear tester evaluate The consisted three test sections different patterns. gyratory compactor adjustments several parameters. Results this indicate that current protocol produces specimens...

Field data from a section of heavily instrumented concrete pavement on the Gene Snyder Freeway (I-265), Louisville, Kentucky were closely examined. To predict mechanical behavior rigid pavement, three-dimensional (3D) finite element model was developed using ANSYS program. The 3D successfully implemented for predicting stresses and strains in slabs. An important conclusion this study that temperature-induced responses more significant than traffic-induced responses. This is very finding, can...

Mechanistic–empirical (ME) pavement design often demands default or assumed axle load spectrum data. Using single and tandem axles of the Vehicle Class 9 as examples, this study analyzed spatial temporal variations distributions from long-term performance program traffic database. The found that both are significant; therefore, it may be questionable to use a distribution factor (LDF) for each type vehicle class in design. However, when conducting cluster analysis, large amount data can...

A dynamic modulus master curve for asphalt concrete is a critical input flexible pavement design in the Mechanistic–Empirical Pavement Design Guide developed NCHRP Project 1-37A, which has drawn much attention among technologists. The objectives this study were ( a) to consider and compare different analysis techniques construction of b) measure analyze effect permanent strain on samples that have been evaluated with one simple performance tests, modulus. It was found differences existed...

The mechanistic–empirical pavement design guide (MEPDG), developed under the recently completed NCHRP Project 1–37A, is a complex tool. Sensitivity analyses typically vary single input parameter while holding other parameters constant. A pilot project outlined to identify feasibility of global sensitivity analysis process by using random sampling techniques over entire space. This study sampled following flexible variables: hot-mix asphalt (HMA) base nominal aggregate size, climate location,...

Some states have recommended changing the definition of flat and elongated aggregates from 5:1 to 3:1 an increase in maximum allowable percentage (F&E) particles 20% or higher Superpave aggregate specification. Engineering justification performance data are required rationally establish criteria for this change. The objectives research included statistical analysis indicators mixtures containing different levels particles. Three mixes were designed tested using 0, 15, 40% a set Kentucky...

This paper deals with accuracy issues related to using ground penetrating radar (GPR) for determining the surface layer thickness of asphalt and concrete pavements. Additionally, tests were conducted identify GPR’s repeatability on dry versus wet Finally, an attempt was made determine number actual field cores necessary accurately postprocess data into data. At this time, it appears that four calibration would be optimum minimize errors.

Incorporation of used tires in asphalt mixtures has been a major advancement the using recycled materials pavements. Tires contain some polymeric components that have to modify binders for decades, but solid form. This paper presents result research examine whether or not proper application tire rubber can enhance pavement's mechanical properties same degree traditional binder modifiers do. The performance terminal blend mixture was compared polymer-modified through testing at Asphalt...

Curling stresses in rigid pavements are the result of temperature gradient through thickness concrete slab. These have a periodic nature, and induced cyclic flexural curling lead to cracking In previous research by authors, phase change material (PCM)-rich overlay was proposed as an effective method control this failure mechanism. A PCM-rich is surface layer that contains relatively high percentage PCM. study, phenomenological approach employed, it demonstrated incorporation PCM improves...

The utilization of circulating fluidized bed combustion (CFBC) ash to make cement products that provide added value and offset CO~2~ production is the objective this research. CFBC burns coal in presence a slaked limestone, which effectively absorbs sulfur dioxide (SO~2~) form anhydrite (CaSO~4~). produces two kinds spent materials, coarse bottom much finer fly ash. Both these are very high calcium. When properly conditioned, materials capable acting as hydraulic cements, forming both...

The mechanistic–empirical pavement design guide (MEPDG), developed under the recently completed NCHRP Project 1–37A, is a complex tool. Sensitivity analyses typically vary single input parameter while holding other parameters constant. A pilot project outlined to identify feasibility of global sensitivity analysis process by using random sampling techniques over entire space. This study sampled following flexible variables: hot-mix asphalt (HMA) base nominal aggregate size, climate location,...

The purpose of this study was to assess ways by which creativity may be enhanced in a design-oriented course. In order demonstrate the validity approach, statistically based employed. Additionally, experiment replicated two fields at University Kentucky. These were civil engineering and interior design. revealed that performance as result special training module. This shown valid both design disciplines.

This paper presents the results of an experimental investigation on interface bond strength between reinforcing fibers embedded in a calcium sulfoaluminate (CSA) cement matrix, utilizing single-fiber pullout test. Bonding at fiber–matrix plays important role controlling mechanical performance cementitious composites. To examine within CSA and portland system, with differing elastic modulus strengths were selected, including polyvinyl-alcohol (PVA), polypropylene, coated steel, plain steel....

Laboratory compaction is an important part of asphalt mix design. For the design process to be effective, laboratory must adequately simulate field compaction. In this study mechanical properties measured with Superpave® shear tester were used evaluate and The consisted three test sections different patterns. Superpave gyratory compactor adjustments several parameters. Results indicate that current protocol produces specimens significantly than those cores produced same material compacted...