Yang H. Huang

Bio: Yang H. Huang is an academic researcher. The author has contributed to research in topics: Falling weight deflectometer & Pavement engineering. The author has an hindex of 1, co-authored 1 publications receiving 2607 citations.

Pavement analysis and design

Abstract: This is a textbook on the structural analysis and design of highway pavements. It presents the theory of pavement design and reviews the methods developed by several organizations, such as the American Association of State Highway and Transportation Officials (AASHTO), the Asphalt Institute (AI), and the Portland Cement Association (PCA). It can be used for an undergraduate course by skipping the appendices or as an advanced graduate course by including them. The book is organized in 13 chapters. Chapter 1 introduces the historical development of pavement design, the major road tests, the various design factors, and the differences in design concepts among highway pavements, airport pavements, and railroad trackbeds. Chapter 2 discusses stresses and strains in flexible pavements. Chapter 3 presents the KENLAYER computer program, based on Burmister's layered theory, including theoretical developments, program description, comparison with available solutions, and sensitivity analysis on the effect of various factors on pavement responses. Chapter 4 discusses stresses and deflections in rigid pavements due to curling, loading, and friction, as well as the design of dowels and joints. Influence charts for determining stresses and deflections are also presented. Chapter 5 presents the KENSLABS computer program, based on the finite element method, including theoretical developments, program description, comparison with available solutions, and sensitivity analysis. Chapter 6 discusses the concept of equivalent single-wheel and single-axle loads and the prediction of traffic. Chapter 7 describes the material characterization for mechanistic-empirical methods of pavement design including the determination of resilient modulus, fatigue and permanent deformation properties, and the modulus of subgrade reaction. Chapter 8 outlines the subdrainage design including general principles, drainage materials, and design procedures. Chapter 9 discusses pavement performance including distress, serviceability, skid resistance, nondestructive testing, and the evaluation of pavement performance. Chapter 10 illustrates the reliability concept of pavement design in which the variabilities of traffic, material, and geometric parameters are all taken into consideration. A probabilistic procedure, developed by Rosenblueth, is described and two probabilistic computer programs including VESYS for flexible pavements and PMRPD for rigid pavements are discussed. Chapter 11 outlines an idealistic mechanistic method of flexible pavement design and presents in detail the AI method and the AASHTO method, as well as the design of flexible pavement shoulders. Chapter 12 outlines an idealistic mechanistic method of rigid pavement design and presents in detail the PCA method and the AASHTO method. The design of continuous reinforced concrete pavements and rigid pavement shoulders is also included. Chapter 13 outlines the design of overlay on both flexible and rigid pavements including the AASHTO, AI, and PCA procedures. An Author Index and a Subject Index are provided.

Fatigue and healing characterization of asphalt mixtures

Abstract: This paper investigates the effect of the processes on fatigue fracture and fracture healing during controlled-strain, dynamic mechanical analysis (DMA) testing. Sand asphalt samples were fabricated with two SHRP-classified binders: AAD-1 and AAM-1. DMA testing was performed at 25°C and at 10 Hz. The mechanical response during DMA testing was monitored using three different damage indicators: (1) change in dynamic modulus; (2) change in pseudo stiffness; and (3) change in dissipated strain energy. When either of these parameters are plotted versus the number of load cycles, two inflection points are apparent that define a significant change in sample behavior due to damage. The second inflection point is a reasonable definition of failure, as it is strongly correlated with the peak of the plot of phase angle versus load repetitions. Furthermore, the phase angle drops precipitously at the second inflection point. By performing controlled-strain torsional fatigue tests at three different strain levels, each great enough to induce damage, a reproducible fatigue relationship (number of load cycles as a function of stress level) is developed. The introduction of several rest periods during testing lengthened fatigue life. Successful development of this testing method is suggested as a potential specification-type test method because of its efficiency, reproducibility, and reliability.

Disk-shaped Compact Tension Test for Asphalt Concrete Fracture

Abstract: A disk-shaped compact tension (DC(T)) test has been developed as a practical method for obtaining the fracture energy of asphalt concrete. The main purpose of the development of this specimen geometry is the ability to test cylindrical cores obtained from in-place asphalt concrete pavements or gyratory-compacted specimens fabricated during the mixture design process. A suitable specimen geometry was developed using the ASTM E399 standard for compact tension testing of metals as a starting point. After finalizing the specimen geometry, a typical asphalt concrete surface mixture was tested at various temperatures and loading rates to evaluate the proposed DC(T) configuration. The variability of the fracture energy obtained from the DC(T) geometry was found to be comparable with the variability associated with other fracture tests for asphalt concrete. The ability of the test to detect changes in the fracture energy with the various testing conditions (temperature and loading rate) was the benchmark for determining the potential of using the DC(T) geometry. The test has the capability to capture the transition of asphalt concrete from a brittle material at low temperatures to a more ductile material at higher temperatures. Because testing was conducted on ungrooved specimens, special care was taken to quantify deviations of the crack path from the pure mode I crack path. An analysis of variance of test data revealed that the prototype DC(T) can detect statistical differences in fracture energy resulting for tests conducted across a useful range of test temperatures and loading rates. This specific analysis also indicated that fracture energy is not correlated to crack deviation angle. This paper also provides an overview of ongoing work integrating experimental results and observations with numerical analysis by means of a cohesive zone model tailored for asphalt concrete fracture behavior.

Utilization of Construction and Demolition Debris Under Traffic-Type Loading in Base and Subbase Applications

Abstract: As construction and remediation take place throughout New Jersey, the amount of construction and demolition debris increases, while the availability of landfill space decreases. A viable solution for disposing of these materials is to incorporate them into base and subbase applications. An extensive laboratory program was conducted on two types of construction and demolition debris: recycled concrete aggregate (RCA) and recycled asphalt pavement aggregate (RAP). These two materials were compared with dense-graded aggregate base coarse (DGABC), which currently is being used in roadway base applications in New Jersey. Both RCA and RAP were mixed at various percentages with the DGABC to evaluate whether an optimum mix blend could be formulated. The materials were evaluated under a traffic-type loading scheme that included resilient modulus and permanent deformation via cyclic triaxial testing. Laboratory tests indicated that the RAP, RCA, and DGABC blended materials all obtained higher resilient modulus values than the currently used DGABC. The permanent deformation results indicated that the RCA mixed samples obtained the lowest amount of permanent deformation when the material was cyclically loaded to 100,000 cycles. In contrast, the permanent deformation testing on RAP mixed samples resulted in the highest amount of permanent deformation at the same number of cycles. Existing models currently used for quarried base and subbase materials were used to predict the permanent deformation in the recycled materials. Laboratory test results indicated that these models could be used for predicting permanent deformation in unbound recycled materials.