Dynamic Modulus of Asphalt Mixtures

2015 ◽  
Vol 2507 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Samuel B. Cooper ◽  
Louay N. Mohammad ◽  
Mostafa A. Elseifi ◽  
Amar Raghavendra
Keyword(s):  
Performance Prediction ◽  
Dynamic Modulus ◽  
Complex Modulus ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Maximum Aggregate Size ◽  
Production Plant ◽  
Pavement Distress ◽  
Pavement Performance Prediction

Mix properties that deviate appreciably from the design properties during the production and construction of asphalt mixtures can lead to premature pavement distress or even failure. The objective of this study was to quantify the differences in the dynamic modulus of specimens prepared during design, production, and construction of dense-graded asphalt pavements and their effects on pavement performance prediction. For the achievement of this objective, Superpave® mixtures were collected from Iowa, Florida, Virginia, Michigan, South Dakota, Louisiana, Minnesota, and Wisconsin during design [laboratory-mixed and laboratory-compacted (LL)], production [plant-produced and laboratory-compacted (PL)], and construction [plant-produced and field-compacted (PF) specimens]. The nominal maximum aggregate size was kept constant at 12.5 mm. An indirect tension dynamic complex modulus (IDT | E*|) was measured for the three specimen types (i.e., LL, PL, and PF). Results showed that laboratory-compacted and field-compacted specimens exhibited large and significant differences. This finding was attributed to differences in the compaction effort and procedure between the field and the laboratory. Results of the AASHTOWare Pavement ME Design showed that the use of dynamic moduli obtained from different specimen types would result in significant differences in pavement performance prediction. This research was part of NCHRP Project 9-48, Field Versus Laboratory Volumetrics and Mechanical Properties.

Evaluating Dynamic Modulus for Indiana Mechanistic-Empirical Pavement Design Guide Practice

2019 ◽  
Vol 2673 (2) ◽  
pp. 346-357 ◽  
Author(s):  
Dario Batioja-Alvarez ◽  
Jusang Lee ◽  
Tommy Nantung
Keyword(s):  
Dynamic Modulus ◽  
Functional Performance ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Pavement Design ◽  
Maximum Aggregate Size ◽  
Pavement Distress ◽  
Design Guide ◽  
Pavement Structures ◽  
Level I

After the implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) in Indiana, an overall evaluation of the stiffness characteristics of local AC mixtures and the ability of level III MEPDG predictive equations to estimate dynamic modulus (E*) with local mixtures was required. Therefore, the primary objectives of this study were to identify significant differences among Indiana asphalt mixtures, to evaluate the performance of commonly used E* predictive models, and to assess the influence of level III E* input on the pavement design life of typical pavement structures. It was found that Indiana mixtures do not show extensive variability among mixtures having the same nominal maximum aggregate size. When conducting a statistical analysis to group asphalt mixtures having similar characteristics, few mixtures were left out of the groups. In general, it was observed that mixtures having Ndes equal to 75, showed the lowest E* values along the entire frequency range. The Witczak 1-37A showed the most accurate and less biased E* predictions for Indiana mixtures. It showed the highest R2, and the least deviation from the measured E* values. However, predicted E* input values produced higher levels of pavement distress compared with measured E* values, indicating general overprediction. Besides, using level III (predictive) rather than level I (measured) E* input values can influence the pavement thickness design due to the functional performance (i.e., the International Roughness Index (IRI)). When a structural performance (i.e., bottom-up cracking) was taken into consideration, no influence of the E* input type on the design AC layer thickness was observed.

Evaluation of Small Specimen Geometries for Asphalt Mixture Performance Testing and Pavement Performance Prediction

2017 ◽  
Vol 2631 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Kangjin Lee ◽  
Sonja Pape ◽  
Cassie Castorena ◽  
Y. Richard Kim
Keyword(s):  
Phase Angle ◽  
Dynamic Modulus ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Aggregate Size ◽  
Pavement Performance ◽  
Maximum Aggregate Size ◽  
Small Specimen ◽  
Test Results ◽  
Multiple Test

The use of small specimen geometries in asphalt mixture performance testing to enable the testing of as-built pavement layers has been gaining attention in recent years. Small specimens could also improve the testing efficiency of laboratory-fabricated specimens by allowing the extraction of multiple test specimens per gyratory-compacted sample. Rigorous assessment of the small specimen geometries is required before the use of such geometries is standardized. In this study, small specimens were evaluated for dynamic modulus and simplified viscoelastic continuum damage fatigue. Three specimen geometries (100-mm- and 38-mm-diameter cylindrical specimens and 25- × 50-mm prismatic specimens) were compared by using five mixtures with a nominal maximum aggregate size (NMAS) ranging from 9.5 to 25.0 mm. The results show that the dynamic modulus and phase angle master curves agreed at low and intermediate temperatures, regardless of the NMAS values of the mixture. At the high temperature, the small specimen dynamic modulus values were slightly higher and the phase angle values were slightly lower than those of the large specimens. The specimen-to-specimen variability for the large and small specimens was comparable. The fatigue test results for the mixtures evaluated were comparable, except for the 25-mm mixture, which proved problematic in the testing of both small and large specimens. Pavement performance was predicted by the layered viscoelastic analysis for critical distresses program by using the test results for the small and large specimens. These results suggest that specimen geometry had a minimal effect on pavement fatigue damage predictions, which indicates promise for the use of small specimen geometries in practice.

Laboratory-Measured Dynamic Modulus and Predicted Performance of Asphalt Mixtures

2015 ◽  
Vol 2507 (1) ◽  
pp. 78-89
Author(s):  
Samuel B. Cooper ◽  
Louay N. Mohammad ◽  
Mostafa A. Elseifi ◽  
Amar Raghavendra
Keyword(s):  
Performance Prediction ◽  
Dynamic Modulus ◽  
Axial Loading ◽  
Fatigue Cracking ◽  
Asphalt Mixtures ◽  
Experimental Program ◽  
Dynamic Moduli ◽  
Loading Mode ◽  
Dynamic Modulus Test ◽  
Pavement Performance Prediction

The dynamic modulus testing of asphalt mixtures is typically conducted by using a specimen 100 mm in diameter and 150 mm tall loaded along its primary axis (axial mode). This specimen orientation can present problems when as-built pavement layers, which are seldom constructed in 150-mm lifts, are evaluated. For this issue to be addressed, dynamic modulus testing in the indirect tension (IDT) loading mode was proposed. The objective of this study was to evaluate the influence of loading mode (axial versus IDT) on the measured dynamic modulus and the effects of the measured difference on pavement performance prediction. For the achievement of these objectives, Superpave® mixtures were collected from Florida, Iowa, Louisiana, Michigan, Minnesota, South Dakota, Virginia, and Wisconsin and were evaluated for the effects of loading mode. Results of the experimental program showed that statistical differences exist between IDT and uniaxial dynamic modulus values measured at different temperatures and frequencies. When the precision of the dynamic modulus test was considered, differences attributable to the loading mode (IDT versus axial) were observed for measurements conducted at all temperatures, with the dynamic moduli measured in the axial loading mode being stiffer than the dynamic moduli measured in the IDT loading mode. Results also showed that performance prediction was significantly affected by the loading mode. Predicted rutting and fatigue cracking in the asphalt layer were the most influenced distresses. Correlation factors were developed to correlate one set of dynamic moduli to the moduli measured in a different loading mode.

Evaluation of Viscoelastic and Fracture Properties of Asphalt Mixtures with Long-Term Laboratory Conditioning

2018 ◽  
Vol 2672 (28) ◽  
pp. 503-513 ◽  
Author(s):  
Reyhaneh Rahbar-Rastegar ◽  
Jo Sias Daniel ◽  
Eshan V. Dave
Keyword(s):  
Viscoelastic Properties ◽  
Complex Modulus ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Cracking Behavior ◽  
Fracture Properties ◽  
Fracture Parameters

Aging affects the properties of asphalt mixtures in different ways; increase of stiffness, decrease of relaxation capability, and the increase of brittleness, resulting in changes in cracking behavior of asphalt mixtures. In this study, ten plant-produced, lab-compacted mixtures with various compositions (recycled materials, binder grades, binder source, and nominal maximum aggregate size) are evaluated at different long-term aging levels (24 hours at 135°C, 5 days at 95°C, and 12 days at 95°C on loose mix and 5 days at 85°C on compacted specimens). The asphalt mixture linear viscoelastic properties (|E*| and δ) and master curve shape parameters measured from complex modulus testing and fracture properties (measured from disc-shaped compact tension and semi-circular bending fracture testing) are compared at different levels of aging. The results indicate that the mixture exposure time to aging is proportional to the dynamic modulus and phase angle changes. Generally, the fracture parameters of mixtures become worse when aging level changes from 5 to 12 days aging. In spite of the similar viscoelastic properties, the mixtures with 24 hours at 135°C and 12 days at 95°C aging do not show similar fracture parameters.

Pavement Management Systems: Past, Present, and Future

2003 ◽  
Vol 1853 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Ram B. Kulkarni ◽  
Richard W. Miller
Keyword(s):  
Performance Prediction ◽  
Prediction Models ◽  
Pavement Management ◽  
Pavement Performance ◽  
Management Systems ◽  
Seamless Integration ◽  
Positioning Systems ◽  
Pavement Management Systems ◽  
Transportation Organization ◽  
Pavement Performance Prediction

The progress made over the past three decades in the key elements of pavement management systems was evaluated, and the significant improvements expected over the next 10 years were projected. Eight specific elements of a pavement management system were addressed: functions, data collection and management, pavement performance prediction, economic analysis, priority evaluation, optimization, institutional issues, and information technology. Among the significant improvements expected in pavement management systems in the next decade are improved linkage among, and better access to, databases; systematic updating of pavement performance prediction models by using data from ongoing pavement condition surveys; seamless integration of the multiple management systems of interest to a transportation organization; greater use of geographic information and Global Positioning Systems; increasing use of imaging and scanning and automatic interpretation technologies; and extensive use of formal optimization methods to make the best use of limited resources.

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

scholarly journals Laboratory Evaluation of Hot Asphalt Concrete Properties with Cuban Recycled Concrete Aggregates

2018 ◽  
Vol 10 (8) ◽  
pp. 2590 ◽  
Author(s):  
Debora Acosta Alvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio Tenza-Abril
Keyword(s):  
Asphalt Concrete ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Demolition Waste ◽  
Aggregate Fraction

Recycled Aggregates (RA) from construction and demolition waste (CDW) are a technically viable alternative to manufacture of asphalt concrete (AC). The main objective of this work is to evaluate the properties of hot asphalt mixtures that have been manufactured with different sources of CDW (material from concrete test specimens, material from the demolition of sidewalks and waste from prefabrication plants) from Cuba. Dense asphalt mixtures were manufactured with a maximum aggregate size of 19 mm, partially replacing (40%) the natural aggregate fraction measured between 5 mm and 10 mm with three types of RA from Cuba. Marshall specimens were manufactured to determine the main properties of the AC in terms of density, voids, stability and deformation. Additionally, the stiffness modulus of the AC was evaluated at 7 °C, 25 °C and 50 °C. The results corroborate the potential for using these sources of CDW from Cuba as a RA in asphalt concrete, thereby contributing an important environmental and economic benefit.

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