Design and Performance Evaluation of Fine-Graded Permeable Friction Course

2012 ◽  
Vol 2293 (1) ◽  
pp. 48-54
Author(s):  
Cindy Estakhri ◽  
Tom Scullion ◽  
Xiaodi Hu
Keyword(s):  
Water Flow ◽  
Laboratory Testing ◽  
Aggregate Size ◽  
Maximum Aggregate Size ◽  
Void Content ◽  
Rain Event ◽  
Air Voids ◽  
Aggregate Fraction ◽  
Air Temperatures ◽  
And Performance

Permeable friction courses (PFCs) are popular in Texas, where the current specification for PFC (Item 342) has a maximum aggregate size of 1/2 in. and is typically placed in layer thicknesses of 1.5 to 2 in. In this study fine-graded PFCs composed of a single aggregate fraction are proposed for placement at a nominal thickness of 1 in. Initial laboratory testing found that the target air void content for volumetric design would be around 26% air voids, substantially higher than the current PFC designs, which are between 18% and 22% air voids. To minimize the likelihood of failure, extensive laboratory testing was performed to arrive at the proposed design. Tests included Hamburg wheel-track testing, overlay tester cracking, and Cantabro, draindown, and water flow tests. The proposed fine PFC mix was first placed on a test track in Pecos, Texas. Two designs were placed and subjected to limited traffic loadings, field water flow, noise, and skid measurements. These test sections performed well. The next section was placed on a Texas Department of Transportation project in May 2011 and subjected to extremely intense traffic loading conditions on an exit ramp on US-59 in Lufkin. This ramp has a high frequency of wet-weather accidents. In addition to extreme traffic loads, the surface experienced extreme heat (air temperatures approaching 105°F) and heavy localized rain (a 6-in. rain event within a 24-h period). After 3 months the fine PFC is holding up well.

scholarly journals A GPR-Based Pavement Density Profiler: Operating Principles and Applications

2021 ◽  
Vol 13 (13) ◽  
pp. 2613
Author(s):  
Nectaria Diamanti ◽  
A. Peter Annan ◽  
Steven R. Jackson ◽  
Dylan Klazinga
Keyword(s):  
Asphalt Pavement ◽  
Wave Impedance ◽  
Asphalt Mixtures ◽  
Void Content ◽  
Air Voids ◽  
New Instrument ◽  
Pavement Engineering ◽  
And Performance ◽  
Air Void ◽  
Air Void Content

Density is one of the most important parameters in the construction of asphalt mixtures and pavement engineering. When a mixture is properly designed and compacted, it will contain enough air voids to prevent plastic deformation but will have low enough air void content to prevent water ingress and moisture damage. By mapping asphalt pavement density, areas with air void content outside of the acceptable range can be identified to predict its future life and performance. We describe a new instrument, the pavement density profiler (PDP) that has evolved from many years of making measurements of asphalt pavement properties. This instrument measures the electromagnetic (EM) wave impedance to infer the asphalt pavement density (or air void content) locally and over profiles.

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.

Field inspection and laboratory testing of highway pavement rutting

2000 ◽  
Vol 27 (6) ◽  
pp. 1109-1119 ◽  
Author(s):  
Turki I Al-Suleiman ◽  
Mohammed Taleb Obaidat ◽  
Ghassan T Abdul-Jabbar ◽  
Taisir S Khedaywi
Keyword(s):  
Dynamic Modulus ◽  
Laboratory Testing ◽  
Permanent Deformation ◽  
Physical And Mechanical Properties ◽  
Void Content ◽  
Foundation Soil ◽  
Traffic Loading ◽  
Air Voids ◽  
Marshall Test ◽  
Highway Pavement

The main objective of this research was to investigate the contribution of pavement characteristics, traffic, and physical and mechanical properties of asphaltic mixtures to highway pavement rutting. A total of 51 pavement sections from the rural highway network in Jordan were selected for a case study. The average rut depths for these sections were measured and three cores were drilled for comprehensive laboratory testing. The investigation was performed using four approaches. The first approach considered pavement characteristics represented by surface thickness, last overlay thickness, pavement age, and subgrade California bearing ratio. The average annual equivalent single axle load was also included in this approach. The second approach included Marshall test parameters such as stability, flow, stiffness, and Marshall modulus. The third approach dealt with the effect of mixture air voids on rutting. The variables examined in this approach include air void content within the ruts, voids between ruts, voids near the pavement centerline, and the difference between centerline and rut voids. The fourth approach considered the dynamic permanent deformation characteristics of the pavement surface layer represented by the dynamic modulus. Regression analysis techniques were employed to develop statistical relationships between average rut depths and the parameters examined in each individual approach. The combined effect of these significant parameters on pavement rutting was also examined for prediction purposes. Rutting formation was found to be most dependent on the traffic loading, dynamic modulus of the bituminous mixture and its susceptibility to further compaction, and foundation soil strength.Key words: pavement rutting and characteristics, Marshall test, traffic loading, air voids, static creep, dynamic permanent deformation.

Impact of Gyration Reduction and Design Specification Changes on Volumetric Properties of Virginia Dense-Graded Asphalt Mixtures

2018 ◽  
Vol 2672 (28) ◽  
pp. 143-153 ◽  
Author(s):  
Stacey D. Diefenderfer ◽  
Benjamin F. Bowers ◽  
Kevin K. McGhee
Keyword(s):  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Design Parameters ◽  
Maximum Aggregate Size ◽  
Volumetric Properties ◽  
Air Voids ◽  
Asphalt Mix ◽  
Production Value ◽  
Virginia Department ◽  
Air Void

In 2015, the Virginia Department of Transportation (VDOT) proposed changes to their specification for asphalt mix design. The changes incorporated a reduction of design gyrations from 65 to 50; the addition of constraints on the No. 4 (4.75 mm) and No. 30 (600 µm) sieves; and adjustments to the production value for voids filled with asphalt and minimum voids in mineral aggregate. Before these modifications were fully adopted, a study was performed to assess the effect of the changes on mixture properties and laboratory performance. Eleven pairs of asphalt mixtures were evaluated; the pairs consisted of a typical VDOT 65-gyration mixture produced under the specification current at the time and a companion 50-gyration mixture designed and produced in accordance with the proposed specification. Mixtures were evaluated to determine the effect of the design parameters on volumetric properties, gradation, and permeability. The changes had very little effect on volumetric properties or gradation. Permeability effects were mixed, with 9.5 mm nominal maximum aggregate size mixtures requiring greater compaction to meet permeability requirements and 12.5 mm nominal maximum aggregate size mixtures showing improved permeability even at higher air-void contents. For the 50-gyration mixtures, core air voids were reduced, indicating the potential for increased durability attributable to improved densification in the field.

Laboratory Evaluation of Mixture Type on Highly Modified Asphalt Mixtures in Virginia

2018 ◽  
Vol 2672 (28) ◽  
pp. 59-68
Author(s):  
Benjamin F. Bowers
Keyword(s):  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Air Voids ◽  
Modified Asphalt ◽  
Modified Asphalt Binder ◽  
Dynamic Modulus Test ◽  
Scb Specimen

The work presented attempts to address reflective cracking of asphalt-surfaced pavements through binder modification with a highly polymer (HP)-modified asphalt binder. Nine asphalt mixtures ranging from fine dense-graded mixtures to stone matrix asphalt (SMA) mixtures were investigated with conventional polymer modified binders and HP binder. The dynamic modulus test, overlay test (OT), and semi-circular bend (SCB) test were used to evaluate the mixtures. In the cracking tests, HP mixtures outperformed the conventionally modified control mixtures for the same mixture type. For HP mixtures, in general, SMA mixtures performed better in the cracking test than dense-graded mixtures. One of the dense-graded mixtures having larger nominal maximum aggregate size (NMAS) performed better than the mixture with a smaller NMAS, whereas the other having a larger NMAS was not significantly different in crack testing. Further, a discussion on the calculation of bulk specific gravity and percent air voids in a cut OT and SCB specimen using saturated surface dry or vacuum sealing methods is presented.

Evaluation of Ability of Superpave Shear Tester To Differentiate Between Mixtures with Different Aggregate Sizes

1998 ◽  
Vol 1630 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Pedro Romero ◽  
Walaa S. Mogawer
Keyword(s):  
Aggregate Size ◽  
Complete Analysis ◽  
Maximum Aggregate Size ◽  
Air Voids ◽  
Asphalt Cement ◽  
Testing Sequence ◽  
Superpave Gyratory Compactor ◽  
Constant Height ◽  
Direct Measurements ◽  
Shear Tester

A study was conducted to determine whether the results from the Superpave shear tester (SST) could measure the effect of nominal maximum aggregate size on rutting susceptibility of asphalt mixtures without the need of a model. Four mixtures were analyzed using direct measurements from the SST. Two of the mixtures were prepared with AC-5 asphalt cement and nominal maximum aggregate sizes of 19.0 mm and 37.5 mm. The other two were prepared with AC-20 asphalt cement and the same two gradations. The results were analyzed statistically and compared with the performance of the respective mixtures tested by the FHWA Accelerated Loading Facility (ALF). The specimens were compacted to a target air voids of 7 percent using the Superpave gyratory compactor. The testing sequence consisted of performing the simple shear at constant height (SSCH) test followed by the frequency sweep at constant height (FSCH) test at 40°C and 58°C. These temperatures were chosen because they represent, respectively, the highest temperature used in Superpave complete analysis and the target pavement temperature at 20 mm depth used in the ALF tests. After the SSCH and FSCH tests, the repeated shear at constant height (RSCH) test was performed on all samples at 40°C. The ALF provided a significant decrease in rutting susceptibility with increase in aggregate size; however, the SST was unable to separate mixtures with the same binders and the two different nominal maximum aggregate sizes.

Analysis of Quality Control and Quality Assurance Data for Superpave Mixes

2000 ◽  
Vol 1712 (1) ◽  
pp. 25-34 ◽  
Author(s):  
Frazier Parker ◽  
M. Shabbir Hossain ◽  
Jiansheng Song
Keyword(s):  
Quality Control ◽  
Quality Assurance ◽  
Aggregate Size ◽  
Mix Design ◽  
Maximum Aggregate Size ◽  
Air Voids ◽  
Density Measurements ◽  
Control Quality ◽  
Asphalt Content ◽  
Mat Density

Asphalt content, voids, and mat density quality control–quality assurance data were collected for selected Marshall and Superpave mixes during 1997 and for selected Superpave mixes during 1998 and 1999. Analyses indicate that the accuracies and variabilities of asphalt content measurements for Marshall and Superpave mixes are comparable. However, analyses also indicate that the accuracies and variabilities of voids and mat density measurements are not comparable. Moreover, variabilities for Superpave mixes are much higher, and measurements for Superpave mixes are more off target than those for Marshall mixes. The effects of gyratory compactor use, mix design range for an equivalent single-axle load, and maximum aggregate size were investigated to explain the observed differences. Although few consistent trends were observed, all these factors seem to affect the variabilities and accuracies of air voids and mat densities of Superpave mixes.

scholarly journals Virtual Asphalt to Predict Roads’ Air Voids and Hydraulic Conductivity

2018 ◽  
Author(s):  
Mustafa Aboufoul ◽  
Andrea Chiarelli ◽  
Isaac Triguero ◽  
Alvaro Garcia
Keyword(s):  
Hydraulic Conductivity ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
High Dispersion ◽  
Void Content ◽  
Air Voids ◽  
Porous Asphalt ◽  
Pore Networks ◽  
Asphalt Materials ◽  
Air Void

This paper investigates the effects of air void topology on hydraulic conductivity in asphalt mixtures with porosity in the range 14%-31%. Virtual asphalt pore networks were generated using the Intersected Stacked Air voids (ISA) method, with its parameters being automatically adjusted by the means of a differential evolution optimisation algorithm, and then 3D printed using transparent resin. Permeability tests were conducted on the resin samples to understand the effects of pore topology on hydraulic conductivity. Moreover, the pore networks generated virtually were compared to real asphalt pore networks captured via X-ray Computed Tomography (CT) scans. The optimised ISA method was able to generate realistic 3D pore networks corresponding to those seen in asphalt mixtures in term of visual, topological, statistical and air void shape properties. It was found that, in the range of porous asphalt materials investigated in this research, the high dispersion in hydraulic conductivity at constant air void content is a function of the average air void diameter. Finally, the relationship between average void diameter and the maximum aggregate size and gradation in porous asphalt materials was investigated.

scholarly journals Influence of Nominal Maximum Aggregate Size and Aggregate Gradation on Pore Characteristics of Porous Asphalt Concrete

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1355 ◽  
Author(s):  
Wenke Huang ◽  
Xu Cai ◽  
Xiang Li ◽  
Wentian Cui ◽  
Kuanghuai Wu
Keyword(s):  
Asphalt Concrete ◽  
Aggregate Size ◽  
Image Processing Technique ◽  
Maximum Aggregate Size ◽  
Void Content ◽  
High Porosity ◽  
Porous Asphalt ◽  
Air Void ◽  
Porous Asphalt Concrete ◽  
Air Void Content

Porous asphalt concrete (PAC) has been used to improve the traffic conditions in rainy weather due to its high porosity. Aggregate size and gradation have great impact on the connected pore structure, which ultimately affects the permeability of porous asphalt concrete. In this paper, the topological properties of connective pores including pore area, pore circularity, equivalent pore diameter, and void network of porous asphalt concrete with different nominal maximum aggregate sizes and gradations were analyzed using x-ray computer tomography scans and the image processing technique. It was observed that the maximum aggregate sizes will not have significant effect on the percentage of connected pores to total pores for porous asphalt concrete. Furthermore, the percentage of connected pores to total pores is related to the air void content, but for PAC-13 with 20% target air void content or above, the connectivity does not seem to have a sharp increase. Additionally, porous asphalt concrete with a smaller nominal particle size or lower target air void content seems to generate a more concentrated distribution of Eqdiameter. Moreover, pore circularities for porous asphalt concrete with a maximum aggregate size of 10 mm or above are independent of maximum aggregate sizes. Air void contents ranging from 16% to 21% do not have a significant effect on the voids’ circularity. Furthermore, the branching nodes in porous asphalt concrete with a smaller nominal maximum aggregate size or lower target air void content have a more uniform spatial distribution. However, the percentage of cross-linked number to total node raises as the nominal maximum aggregate size or target air void content increases.

Air Void Characterisation in Porous Asphalt Using X-Ray Computed Tomography

2014 ◽  
Vol 911 ◽  
pp. 443-448 ◽  
Author(s):  
Abdul Hassan Norhidayah ◽  
Mohd Zul Hanif Mahmud ◽  
Putra Jaya Ramadhansyah
Keyword(s):  
Computed Tomography ◽  
Aggregate Size ◽  
Size Composition ◽  
Maximum Aggregate Size ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Porous Asphalt ◽  
X Ray ◽  
Specimen Height ◽  
X Ray Computed

This study presents the characterisation of the air voids distribution for porous asphalt mixtures compacted using gyratory compactor. The distribution of voids content and voids shape within the porous asphalt were characterised for different nominal maximum aggregate size (NMAS) and specimen height. This is to evaluate the effect of different aggregate size composition and lift thickness on the air voids characteristics of the compacted porous asphalt. Two types of gradations were adopted i.e. Grading A (with NMAS=10 mm) and Grading B (with NMAS=14 mm) and they were fabricated for two different heights (50 and 100 mm). The internal structure was captured using X-ray Computed Tomography and image analysis techniques were used to process and analyse the images. It was found that mixture with coarse aggregate gradation produced larger void size with an elongated shape, which indicates voids connectivity within the mixture compared to fine gradation with more circular and smaller void size.For lift thickness, itacts differentlyfor different aggregate gradations. The specimen produced greater voids connectivity when the fine and coarse gradations were compacted at 100 mm and 50 mm respectively. These show that NMAS and lift thickness influence the mobility of the aggregate particles during compaction which affect the voids formation and determine the effectiveness of the compaction.

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