Practice for Open-Graded Friction Course (OGFC) Mix Design

2021 ◽  
Author(s):  
2017 ◽  
Vol 12 (2) ◽  
pp. 106-116 ◽  
Author(s):  
Rajan Choudhary ◽  
Dibyatonu Chattopadhyay ◽  
Abhinay Kumar ◽  
Ashok Julaganti

For a fast developing economy like India, expansion, rehabilitation, and maintenance of transportation infrastructure is crucial and require huge quantities of high quality natural aggregates. Meanwhile, vast amounts of industrial wastes accumulating in the country pose problems related to safe and sustainable disposal. The present study investigated possible utilisation of marble dust, a waste from stone industry, and fly ash, a waste from thermal power stations, as filler materials in open-graded friction course mixes. Open-graded friction course mixes incorporating fly ash, marble dust, and two sources of stone dust as filler fractions were designed and evaluated for mix design properties including draindown, abrasion loss, air void content, and permeability. Morphology of each filler was characterised through scanning electron microscopy. Physicochemical properties of fillers were examined through Rigden voids, German filler test, methylene blue, and hydrometer analysis. Analysis of variance using Fisher multiple comparison procedure was performed to evaluate the effect of filler type on design properties of open-graded friction course mixes. Regression analysis using forward selection technique was performed to identify significant filler characteristics influencing open-graded friction course properties. Results showed that filler type affected open-graded friction course design parameters significantly. Open-graded friction course mixes with marble dust showed promising performance with lowest draindown, and highest durability, air voids, and permeability. Regression analysis identified Rigden void content of filler materials as a major filler characteristic affecting the mix design parameters of open-graded friction course mixes.


Author(s):  
Donald E. Watson ◽  
Kathryn Ann Moore ◽  
Kevin Williams ◽  
L. Allen Cooley

Open-graded friction course (OGFC) has been used in the United States for more than 50 years. In 2000, National Center for Asphalt Technology (NCAT) research led to a recommended mix design procedure for a new-generation OGFC, but the work involved only one aggregate source. Therefore, NCAT is in the process of refining this design procedure to ensure that it is applicable to other aggregate types used in surface mixes throughout the United States. The objectives of NCAT's current research are to refine and field validate the new-generation OGFC mix design procedure. This work has led to several experiments. Several objectives have been identified that need to be addressed. Superpave® technology and use of the Superpave gyratory compactor (SGC) need to be incorporated into the mix design procedure. The Cantabro test for durability and resistance to stone loss needs to be adapted to SGC-prepared specimens and performance parameters established. The asphalt draindown test (AASHTO T 305-97), which was developed for stone-matrix asphalt mixtures, also needs to be evaluated for applicability to OGFC mixtures. In addition, a method for effectively evaluating air void criteria needs to be investigated. On the basis of the research conducted in this study, 50 gyrations of the SGC was selected as the design compactive effort during mix design. Also, the use of SGC-prepared samples during the Cantabro test appears to be a reasonable alternative to use of Marshall-compacted samples.


Author(s):  
Zhaoxing Xie ◽  
Nam Tran ◽  
Donald E. Watson ◽  
Lyndi Davis Blackburn

Open Graded Friction Course (OGFC) mixtures are used as the final riding surface on roadways as they offer many benefits, such as reducing hydroplaning, reducing splash and spray behind vehicles for improved driver visibility, improving wet-pavement friction, and reducing surface reflectivity during wet-weather conditions. Despite these benefits, the use of OGFC has diminished over the years due to durability and service-life issues. The typical OGFC pavements in Alabama have exhibited premature distresses (e.g., raveling) after approximately six or seven years in service. Therefore, there is a need to change the current OGFC mix design procedure to improve the mix durability. In this study, three modified OGFC mixtures were designed based on a 12.5-mm OGFC mix design previously approved by the Alabama Department of Transportation (ALDOT) and paved in three test sections (E9A, E9B, and E10) on the National Center for Asphalt Technology pavement test track to evaluate possible changes to ALDOT’s OGFC mix design procedure. The ALDOT-approved mix design lasted less than 20 million equivalent single-axle loads (ESALs) on I-85, a few miles from the test track, whereas the three modified OGFC mixtures lasted more than 20 million ESALs and remained in place for another research cycle (10 millions ESALs) on the test track. The three modified OGFC mixtures also showed improved laboratory performance characteristics compared with those of the ALDOT-approved OGFC mixture. Based on the field and laboratory test results, adjustments made in the three modified OGFC mixtures can potentially improve the long-term field performance of OGFC mixtures in Alabama.


2019 ◽  
Vol 27 (1) ◽  
pp. 366-381
Author(s):  
Ola Abbas Al-Jawad ◽  
Shakir Al-Busaltan

An open-graded friction course (OGFC) is a special type surface layer of traditional Dense Graded Hot Mix Asphalts (DGHMA) pavement that is increasingly being used around the world due to its various benefits, such as, frictional, safety and environmental, etc. In this research, selective laboratory OGFC properties were statistically modeled depends on mix design inputs for two purposes or aims; mix inputs significant and prediction the OGFC properties according mix inputs.  Principally, Indirect Tensile Strength (ITS), water sensitivity (TSR), and permeability (K) were selected from mechanical, durability, and volumetric properties, respectively as an output property; they represent the dependent variables for each model. While, fillers as conventional mineral filler or Ordinary Portland Cement (CMF, or OPC), binder content (BC), and polymer content (SBS) are represented inputs or the independent variables for all models. The generated models offered a vital achievable tool for prediction (e.g., their R² are 0.781, 0.82 1and 0.820, respectively, for the mentioned model’s properties), also it helped to scale the significant of each independent variable (e.g., filler type significantly affect water sensitivity properties, its correlation was 0.752). This study reveals that the statistical modeling is achievable and offers a dynamic tool to describe the characteristics and performance of OGFC mixture in term volumetric, mechanical and durability properties.


Sign in / Sign up

Export Citation Format

Share Document