Evaluation of Job-Mix Formula Tolerances as Related to Asphalt Mixtures Properties

2018 ◽  
Vol 24 (5) ◽  
pp. 124
Author(s):  
Mohammed Qadir Ismael ◽  
Reem Fouad Ahmed Al-Harjan
Keyword(s):  
Evaluation Process ◽  
Maximum Size ◽  
Asphalt Mixtures ◽  
Fine Aggregate ◽  
Compressive Test ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Asphalt Cement ◽  
Marshall Test ◽  
Asphalt Content

The current Iraqi standard specifications for roads and bridges allowed the prepared Job-Mix Formula for asphalt mixtures to witness some tolerances with regard to the following: coarse aggregate gradation by ± 6.0 %, fine aggregate gradation by ± 4.0 %, filler gradation by ± 2.0 %, asphalt cement content by ± 0.3 % and mixing temperature by ± 15 oC. The objective of this work is to evaluate the behavior of asphalt mixtures prepared by different aggregates gradations (12.5 mm nominal maximum size) that fabricated by several asphalt contents (40-50 grade) and various mixing temperature. All the tolerances specified in the specifications are taken into account, furthermore, the zones beyond these tolerances are also observed. The evaluation process is illustrated by volumetric properties such as density, air voids, voids in mineral aggregate and voids filled with asphalt. Marshall test is carried out to find stability and flow values. The resistance to moisture effect is investigated by conducting the compressive test for dry and water immersed conditions to find the index of retained strength. The experimental results supported the recommendations to increase tolerances of coarse and fine aggregate gradations to ± 7.0 % and         ± 5.0 % respectively. The optimum asphalt content tolerance can be increased to ± 0.5 %. The tolerances of filler gradation and mixing temperature are preferable to keep their current values.  

scholarly journals Effect of Gradation Variability on Volume Parameter and Key Performances of HMA

2021 ◽  
Vol 7 ◽  
Author(s):  
Shutang Liu ◽  
Lin Zhu ◽  
Huiqin Zhang ◽  
Tao Liu ◽  
Ping Ji ◽  
...  
Keyword(s):  
Design Theory ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Fine Aggregate ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Air Voids ◽  
Pavement Engineering ◽  
Asphalt Content ◽  
Main Component

The graded mineral aggregate composed of coarse aggregate, fine aggregate, and mineral powder is the main component of hot asphalt mixture (HMA), and it occupies a mass ratio of more than 95% in HMA. The gradation variability of mineral aggregate is frequently an unavoidable problem in the construction of asphalt pavement engineering. In order to investigate the effect of gradation variability on the volume parameters and key performances of HMA, the asphalt concrete with a nominal maximum particle size of 20 mm (AC20) was selected as the research carrier. Firstly, a benchmark mineral aggregate gradation (BMAG) was designed based on the theory of dense skeleton gradation presented in the paper. Secondly, six types of HMA (that is, AC20) with variable gradations were also determined and all the specimens were prepared by rotary compaction process with the same optimum asphalt content (gradation varies but asphalt content remains the same), and finally based on asphalt pavement analyzer, the performances of all the specimens of each gradation were tested. The results show that, compared with the BMAG-HMA, the volume parameters such as air voids, voids in mineral aggregate, and voids filled with asphalt of the variable-graded HMA change in different directions, but the water stability and high-temperature performance both degrade greatly. The experimental results also show the feasibility and effectiveness of the dense skeleton gradation design theory adopted in this study.

Relationships between the Volumetric Parameters and the Marshall Index for Asphalt Mixtures

2012 ◽  
Vol 174-177 ◽  
pp. 947-953 ◽  
Author(s):  
Tong Jiang Fan ◽  
Hao Chen
Keyword(s):  
Orthogonal Test ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Asphalt Pavements ◽  
Fine Aggregate ◽  
Sieve Size ◽  
Marshall Test ◽  
Orthogonal Test Method ◽  
Asphalt Content

determination of the optimum asphalt content usually associates the Marshall Index with volumetric parameters for hot mix asphalt (HMA). Because unreasonable volumetric parameters may result in the asphalt content being more or less so that performance of HMA are influenced. Therefore in this paper, relationships between volumetric parameters and the Marshall Index were studied for two kinds of gradations, AC25 and AC13, which for each kind of gradation, according to the orthogonal test method, the pass percentages of aggregate between the each sieve size and the usage of asphalt contents were changed to form 50 sets of asphalt mixtures for the Marshall test and the volumetric parameters experiment. The results show that rank of influence significance of volumetric parameters on the Marshall Index is Gmb and VV, then VMA and last VFA. However, for fine aggregate (AC13) asphalt mixtures, as Gmb increases, all the MS and the FL increase. Meanwhile, as VV increases, the MS and the FL of AC25 asphalt mixtures increase, whereas for AC13 asphalt mixtures the MS decreases but the FL increases. So for proportion design of fine aggregate (AC13) asphalt mixtures, the fine aggregate and the asphalt content must be strictly controlled to meet the VV requirement and to avoid asphalt pavements to become over-densified. In addition, with VMA increases, for course aggregate (AC25) asphalt mixtures, MS and FL increase, but for course aggregate (AC13) asphalt mixtures, MS decreases but FL increases. Otherwise, the influence of VFA on MS and FL could be nearly ignored.

scholarly journals Studi Karakteristik Campuran AC-Base Menggunakan Batu Gunung Pura Lau Kecamatan Tikala

2021 ◽  
Vol 3 (2) ◽  
pp. 247-255
Author(s):  
Dede Novit Senolinggi ◽  
Alpius ◽  
Charles Kamba
Keyword(s):  
Test Object ◽  
Coarse Aggregate ◽  
Stability Index ◽  
Fine Aggregate ◽  
Regional Government ◽  
Test Tool ◽  
Marshall Test ◽  
Bitumen Content ◽  
Local Residents ◽  
Asphalt Content

This study is to get character each of Laston base mixture using the Mount Pura Lau stone, Tikala District. The methodology in this study is to test each character of the sample to be tested for its, whether it is coarse aggregate, fine aggregate, filler, and asphalt. After testing each character, we will design the composition of the mixture for the manufacture of rough Laston Base (AC-BASE) specimens and obtain several variants of asphalt content, namely 4.5%, 5%, 5.55%, 6%, and 6.5%. After getting the composition, the test object will be made immediately. After the object has been made, it is time to test with Marshall test tool to obtain the residual Marshall Immersion / Stability Index (SMS) or the durability of the mixture using the optimum bitumen content. The results of the optimum asphalt content were 5.5%, MQ 906.88 Kg / mm and immersion index (IP) 96.06% which showed that met the requirements, namely 90% and meets the specifications of Bina Marga. So that it can be used as a recommendation to the regional government and local residents.

Laboratory Investigate of the Effect of Fine Aggregates on Asphalt Mixture Materials

2011 ◽  
Vol 225-226 ◽  
pp. 577-580
Author(s):  
Yong Ye ◽  
Yi Zhou Cai
Keyword(s):  
Compressive Strength ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Fine Aggregate ◽  
Test Results ◽  
Creep Tests ◽  
Aggregate Gradation ◽  
Static Creep ◽  
Fine Aggregates

The objective of this study is to investigate and evaluate the effect of fine aggregates (aggregate size smaller than or equal to 2.36 mm) on the compressive strength and creep behavior of asphalt mixtures. The variables that are considered in the study include the sizes and gradations of fine aggregate. A kind of standant aggregate gradation and four kinds of reduced aggregate gradation mixture specimens are used. Uniaxial compression and static creep tests were realized at different loading conditions. The test results showed that the different fine aggregate sizes do not result in significant differences in compressive strength and creep values using the same percentage of fine aggregates (38.4%). Only the different gradations showed a little differences for mixtures made with different gradations but same aggregate size (between 2.36 and 1.18 mm).

Prediction of Asphalt Cement Content of Compacted Hot-Mix Asphalt Specimens Using Nuclear Gauges

1996 ◽  
Vol 1545 (1) ◽  
pp. 169-177
Author(s):  
Iyad A. Alattar ◽  
Imad L. Al-Qadi
Keyword(s):  
Moisture Content ◽  
Hot Mix Asphalt ◽  
Extraction Methods ◽  
Void Content ◽  
Study Program ◽  
Aggregate Gradation ◽  
Air Voids ◽  
Asphalt Cement ◽  
Specimen Weight ◽  
A New Technique

Determining asphalt cement (AC) content of hot-mix asphalt (HMA) for quality control/quality assurance using extraction methods is a lengthy, time-consuming, and hazardous process. A demand for a faster and safer method led to the development of different nuclear gauges capable of predicting the AC content of HMA samples. Measuring the AC content of compacted specimens by nuclear gauges is a new technique whose feasibility was evaluated. A total of 216 Marshall compacted specimens were cast and tested in an attempt to develop correction models. The study program investigated the effect of various HMA parameters on the measured AC content, including aggregate gradation and type, air void content, moisture content, AC content, and specimen weight. Specimens were prepared at two different mix design formulas using AC-30 and compacted at two different compaction efforts to investigate the effect of air voids. Specimens (1200 g each) used for calibration were prepared at 3 to 7 percent AC content, whereas specimens prepared for measurements were prepared at 4 to 6 percent. Quartzite and diabase aggregate were used as open and dense graded in prepared mixes. Three levels of moisture content in HMA were evaluated. Different calibration models were developed for different asphaltic mixtures. The evaluated nuclear gauge for measuring AC content for compacted HMA specimens produced satisfactory results when the parameters of tested and calibration parameters were the same. The study found that specimen weight is the most significant factor. Other parameters have different degrees of influence on the measured AC content. Statistical models were developed to correct for the evaluated parameters.

92-MPa Air-Entrained High-Performance Concrete Using Tennessee Materials

2000 ◽  
Vol 1698 (1) ◽  
pp. 24-29 ◽  
Author(s):  
L. K. Crouch ◽  
Heather J. Sauter ◽  
Jacob A. Williams
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Maximum Size ◽  
Mixture Design ◽  
Unit Weight ◽  
Fine Aggregate ◽  
Freezing And Thawing ◽  
Aggregate Gradation ◽  
Static Modulus ◽  
Static Modulus Of Elasticity

An air-entrained high-performance concrete (HPC) mixture design for prestressed bridge beams was developed in an attempt to interest the Tennessee Department of Transportation. The mixture contained locally available, 19-mm maximum-size limestone as the coarse aggregate and a manufactured limestone fine aggregate. A dense, combined aggregate gradation was used to lower water demand and thus enhance durability. Type II portland cement, microsilica, and Class C fly ash were used as binder materials. The resulting w/(c + p) was 0.22. Twelve 0.028-m3 batches of the HPC were mixed for the study. The mixture design produced an average air content of 4.1 percent and an average slump of 72 mm. Although it contained 4.1 percent air, the mixture remained very dense, with an average unit weight of 2422 kg/m3. Average compressive strengths of 72.6, 63.3, 84.8, and 92.9 MPa were achieved at simulated release at 7, 28, and 56 days, respectively. Measured static modulus of elasticity at 28 days agreed with ACI 363R-92 equations within 2 percent. Further, after 600 freezing and thawing cycles, the average durability factor of two prismatic specimens was 100, and visible damage was minimal.

A New Formula of Voids in the Mineral Aggregate (VMA) of Hot Mix Asphalt (HMA) and its Application

2010 ◽  
Vol 150-151 ◽  
pp. 1158-1162
Author(s):  
Shu Tang Liu ◽  
Chang Shun Shao ◽  
Wei Dong Cao ◽  
Xiao Liu
Keyword(s):  
Design Process ◽  
Empirical Equation ◽  
Hot Mix Asphalt ◽  
Selection Index ◽  
Volume Index ◽  
Aggregate Gradation ◽  
Mineral Aggregate ◽  
Air Voids ◽  
Asphalt Content ◽  
New Formula

Voids in the mineral aggregate (VMA) is an important volume index for hot mix asphalt (HMA). In the popular HMA design methods such as Superpave system and Marshall Method an accurately calculated VMA is a crucial selection index for the aggregate gradation design. In this article a new formula for calculating VMA is established from the mathematic deduction based on the air voids and traditional VMA formulas. The new built VMA formula can be used to examine the result of the existing empirical equation in the aggregate gradation design process of Superpave. In fact, when the estimated asphalt content is determined according to the initial asphalt content the new formula can completely replace the empirical one for estimating VMA, offering conveniences to calculating.

Field Density Investigation of Asphalt Mixtures in Minnesota

2021 ◽  
pp. 036119812110095
Author(s):  
Tianhao Yan ◽  
Mihai Marasteanu ◽  
Chelsea Bennett ◽  
John Garrity
Keyword(s):  
Material Properties ◽  
Research Effort ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Mix Design ◽  
Maximum Aggregate Size ◽  
Density Level ◽  
Fine Aggregate ◽  
Aggregate Gradation ◽  
Field Density

In a current research effort, University of Minnesota and Minnesota Department of Transportation have been working on designing asphalt mixtures that can be constructed at 5% air voids, similar to the Superpave 5 mix design. High field density of asphalt mixtures is desired because it increases the durability and extends the service life of asphalt pavements. The paper investigates the current situation of field densities in Minnesota, to better understand how much improvement is needed from the current field density level to the desired level, and to identify possible changes to the current mix design to improve field compactability. Field densities and material properties of 15 recently constructed projects in Minnesota are investigated. First, a statistical analysis is performed to study the probability distribution of field densities. Then, a two-way analysis of variance is conducted to check if the nominal maximum aggregate size and traffic levels have any significant effect on field densities. A correlation analysis is then conducted to identify significant correlations between the compactability of mixtures and their material properties. The results show that the field density data approximately obey normal distribution, with an average field density of 93.4% of theoretical maximum specific gravity; there are significant differences in field density between mixtures with different traffic levels; compactability of mixtures is significantly correlated with fine aggregate angularity and fine aggregate gradation of the mixtures.

scholarly journals Utilization of Sewan River Aggregate in Sarmi Regency as a Mixture for AC-WC

2021 ◽  
Vol 3 (3) ◽  
pp. 421-430
Author(s):  
Marine Mariel Pongturunan ◽  
Mary Selintung ◽  
Alpius
Keyword(s):  
Coarse Aggregate ◽  
Rapid Development ◽  
Asphalt Mixture ◽  
Fine Sand ◽  
Immersion Test ◽  
Fine Aggregate ◽  
Marshall Test ◽  
Asphalt Content ◽  
Sand Filler ◽  
Marshall Stability

The rapid development of road infrastructure increases the need for materials to be used, including the use of aggregates. This study aims to examine the use of aggregate from the Sewan River in Sarmi Regency as an asphalt mixture. In this study by conducting several tests such as checking the characteristics of course (stone), fine (sand), filler and asphalt characteristics. After that, a mixture of asphalt composition (AC-WC) was made and then the Marshall test was carried out to obtain the properties of the mixture. The results of testing the composition of the AC-WC mixture obtained the composition of the mixture for the optimum asphalt content of 7.50%, coarse aggregate 36.75%, fine aggregate 50.00%, and filler 5.75%. This shows that the aggregate characteristics of the Sewan river for the AC-WC mixture with the conventional Marshall method that meet the 2018 General Specifications of Highways are stability (Asphalt content 4.00%-11.00%), Flow (Asphalt content 4.00%-11 0.00%), VIM (asphalt content 4.00%-7.50%), VMA (asphalt content 5.75%-11.00%) and VFB (asphalt content 5.75%-11.00%). As for the Marshall Immersion test, the remaining Marshall stability value is 95.15%.  

MARSHALL TEST CHARACTERISTICS OF ASPHALT CONCRETE MIXTURE WITH SCRAPPED TIRE RUBBER AS A FINE AGGREGATE

2017 ◽  
Vol 79 (2) ◽  
Author(s):  
Gito Sugiyanto
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Tire Rubber ◽  
Test Characteristics ◽  
Concrete Mixtures ◽  
Fine Aggregates ◽  
Marshall Test ◽  
Asphalt Content

Highways are important transportation infrastructures that influence economy, culture, and security. Most of the highways in Indonesia are flexible pavement that use asphalt as a binder. The use of scrapped tire rubber as a partial replacement of fine aggregates is based on the limited available natural aggregate in nature. Utilization of scrapped tire rubber as a fine aggregate is one of the alternatives for reducing environmental pollution and supporting Clean Development Mechanism program. The aim of this study is to analyze the Marshall test characteristics of asphalt concrete (AC) mixture that use scrapped tire rubber as a partial substitute of fine aggregate and comparing with a standard mixture. Laboratory tests are performed on three different types of mixtures as follows the mix without scrapped tire rubber, mix containing 50%, and 100% substitution of aggregate at fraction of No.50 with scrapped tire rubber. The test, it show that optimum asphalt content for ACStandard mixture is 6.76%, while ACScrapped-tire 50% mixture is 7.04% and ACScrapped-tire 100% mixture is 6.25%. The use of scrapped tire rubber in asphalt concrete mixtures can improve the resistance to permanent deformation and resistance to water. The use of scrapped tire rubber is acceptable as a partial replacement of aggregate in asphalt concrete mixtures.  

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