Jo Sias Daniel

Bio: Jo Sias Daniel is an academic researcher from University of New Hampshire. The author has contributed to research in topics: Asphalt concrete & Climate change. The author has an hindex of 26, co-authored 119 publications receiving 2342 citations. Previous affiliations of Jo Sias Daniel include North Carolina State University.

Performance characteristics of plant produced high RAP mixtures

Abstract: The main focus of this study was to obtain plant produced Reclaimed Asphalt Pavement (RAP) mixtures, to document the mixture production parameters and to evaluate the degree of blending between the virgin and RAP binders. The effect of mixture production parameters on the performance (in terms of stiffness, cracking, rutting, and moisture susceptibility) and workability of the mixtures was evaluated. Eighteen plant produced mixtures were obtained from three locations in the Northeast United States. RAP contents (zero to 40%) were varied and softer binders were used. The data and analysis illustrated that the degree of blending between RAP and virgin binders is a function of production parameters. The stiffness of the mixtures increased as the percentage of RAP increased, but not when the discharge temperatures of the mixtures were inconsistent. The cracking resistance was reduced as the percentage of RAP increased. The rutting and moisture damage resistance improved as the percentage of RAP in the mixture...

New England Verification of National Cooperative Highway Research Program (NCHRP) 1-37A Mechanistic-Empirical Pavement Design Guide

Abstract: In 1996, the National Cooperative Highway Research Program (NCHRP) launched Project 1-37A to develop a new design guide for pavement structures. The design guide recommended by the project team in 2004 is based on mechanistic-empirical (M-E) principles and is accompanied by software that handles the execution of the design and performance prediction. The mechanistic empirical pavement design guide (MEPDG) software has gone through various version upgrades and improvements to the incorporated models and user interface, the latest being DarwinME. The design inputs needed for the MEPDG software are classified according to a hierarchy system where the designer can select the level of data accuracy and sophistication based on the economic impact of the project. The selection is also a function of the state-of-knowledge and availability of the data. The levels vary from Level 1, for which design inputs are generally site specific and are determined from material testing and/or in-situ measurement to Level 2 and 3, where default or user-selected values obtained from national and regional experiences such as LTTP sites are used. The performance prediction models incorporated in the MEPDG were validated and calibrated using field performance of selected pavement sections throughout the United States. Coefficients incorporated in the models can thus be regarded as national averages derived from the performance measured from the sites selected for the calibration. While the State Highway Agencies (SHAs) can use those models with the “default” coefficients, a higher level of reliability can be achieved in predicting the distresses if the agencies adjust the coefficients to better suit the conditions prevalent in their states. It is widely recognized that local calibration of the models should thus be performed to take full advantage of the MEPDG. The main goal of this research was to offer the New England and New York state highway agencies guidelines for the implementation of the MEPDG for designing flexible pavements and AC overlays. This report documents the current design practices of the six New England States and New York as well as progress of MEPDG implementation initiatives undertaken by other states. A comprehensive sensitivity analysis of the MEPDG Level 2 and 3 inputs for each of the seven states involved in this study was conducted. The extensive software runs conducted allow for an evaluation of the MEPDG functionality and accuracy for the level of inputs used by comparing predicted distresses with field-measured distresses, and provide individual states with an idea on adequacy of their input database and accuracy that the embedded distress models with nationally calibrated coefficients provide. The findings can be used by the state agencies in their decision on whether to start implementing the MEPDG with current models and coefficients and for what level of analysis, and in prioritizing implementation activities.

Continuum damage mechanics-based fatigue model of asphalt concrete

Abstract: A fatigue performance prediction model of asphalt concrete is developed from a uniaxial constitutive model based on the elastic-viscoelastic correspondence principle and continuum damage mechanics through mathematical simplifications. This fatigue model has a form similar to the phenomenological tensile strain-based fatigue model. Therefore, a comparison between the new model and the phenomenological model yields that the regression coefficients in the phenomenological model are functions of viscoelastic properties of the materials, loading conditions, and damage characteristics. The experimental study on two mixtures with compound loading histories demonstrates that the fatigue model maintains all of the strengths of the constitutive model such as its accuracy and abilities to account for the effects of rate of loading, stress/strain level dependency, rest between loading cycles, and mode-of-loading on fatigue life of asphalt concrete.

Laboratory evaluation of fatigue damage and healing of asphalt mixtures

Abstract: The changes in the stiffness of two asphalt concrete mixtures due to temperature, fatigue damage growth, and healing during rest periods are evaluated using the impact resonance method. The impact resonance method is a means of determining the dynamic modulus of elasticity of a specimen nondestructively. The dynamic modulus of elasticity decreases as temperature increases and as microcrack damage growth occurs in the specimen due to fatigue. The impact resonance method also detects increases in dynamic modulus of elasticity after the application of rest periods. A gain in flexural stiffness was also observed from measurements and is attributed to closure of microcracks or healing during the rest period. The amount of healing or stiffness gain appeared to increase when specimens were subject to a higher temperature during the rest period. A qualitative study of the two asphalt mixtures showed that there is a difference between the two with respect to healing performance.

Mechanistic and Volumetric Properties of Asphalt Mixtures with Recycled Asphalt Pavement

Abstract: This research examines how the addition of recycled asphalt pavement (RAP) changes the volumetric and mechanistic properties of asphalt mixtures. A Superpave® 19-mm mixture containing 0% RAP was the control for evaluating properties of mixes containing 15%, 25%, and 40% RAP. Two types of RAP were evaluated: a processed RAP and an unprocessed RAP (grindings). Testing included dynamic modulus in tension and compression, creep compliance in compression, and creep flow in compression. Dynamic modulus and creep compliance master curves were constructed with the use of the time-temperature superposition principle to describe the behavior of each mix over a range of temperatures. The voids in mineral aggregate (VMA) and voids filled with asphalt (VFA) of the RAP mixtures increased at the 25% and 40% levels, and there was also an influence of preheating time on the volumetric properties. The dynamic modulus of the processed RAP mixtures increased from the control to 15% RAP level, but the 25% and 40% RAP mixtures...

American Society for Testing and Materials

Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

Mitigation and Adaptation Strategies for Global Change

Abstract: ▶ Addresses a wide range of timely environment, economic and energy topics ▶ A forum to review, analyze and stimulate the development, testing and implementation of mitigation and adaptation strategies at regional, national and global scales ▶ Contributes to real-time policy analysis and development as national and international policies and agreements are discussed and promulgated ▶ 94% of authors who answered a survey reported that they would definitely publish or probably publish in the journal again

Retardation and repair of fatigue cracks in a microcapsule toughened epoxy composite—Part II: In situ self-healing

Abstract: Successful arrest and retardation of fatigue cracks is achieved with an in situ self-healing epoxy matrix composite that incorporates microencapsulated dicyclopentadiene (DCPD) healing agent and Grubbs first generation Ru catalyst. Healing agent is released into the crack plane by the propagating crack, where it polymerizes to form a polymer wedge, generating a crack tip shielding mechanism. Due to the complex kinetics of healing a growing crack, the resulting in situ retardation and arrest of fatigue cracks exhibit a strong dependence on the applied range of cyclic stress intensity DKI. Significant crack arrest and life-extension result when the in situ healing rate is faster than the crack growth rate. In loading cases where the crack grows too rapidly (maximum applied stress intensity factor is a significant percentage of the mode-I fracture toughness value), a carefully timed rest period can be used to prolong fatigue life up to 118%. At moderate DKI, in situ healing extends fatigue life by as much as 213%. Further improvements in fatigue life-extension are achieved by employing a rest period, which leads to permanent arrest at this moderate DKI. At lower values of applied stress intensity factor, self-healing yields complete arrest of fatigue cracks providing infinite fatigue life-extension. � 2005 Elsevier Ltd. All rights reserved.