Flow Number Test and Assessment of AASHTO TP 79-13 Rutting Criteria

2015 ◽  
Vol 2507 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Maria Carolina Rodezno ◽  
Randy West ◽  
Adam Taylor
Keyword(s):  
Performance Test ◽  
Hot Mix Asphalt ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Standard Protocol ◽  
Test Results ◽  
Flow Number ◽  
Test Parameters ◽  
Traffic Level ◽  
Tp 79

The flow number (FN) test was recommended in NCHRP Project 9-19 as a simple performance test for rutting evaluation of asphalt mixtures. The test showed good correlation with rutting performance of mixtures from WesTrack, MnROAD, and FHWA's accelerated loading facility. Despite this fact, no standard protocol was recommended for temperature and required stress level. Subsequent NCHRP studies allowed the development of a provisional standard. AASHTO TP 79-13 includes test parameters for stress and temperature, specimen conditioning, and minimum FN criteria that were established for hot-mix asphalt (HMA) and for warm-mix asphalt (WMA) on the basis of traffic level. In NCHRP Project 9-47A, the rutting potential of WMA mixtures was compared with that of HMA mixtures by using the FN test and the rutting criteria included in the AASHTO TP 79-13 were also evaluated. The analysis included results of samples produced by using field and lab mixtures. Thirteen mixes using 10 WMA technologies and eight corresponding HMA mixes were included. The FN test results for plant-produced WMA mixes were found to be statistically lower than those for corresponding HMA mixes in more than two-thirds of the comparisons. The study also found that the FN criteria recommended for both HMA and WMA seemed appropriate for evaluating plant-produced mixes. Another finding from the study was that FN results from lab-produced WMA mixtures were consistently lower than FN values from field mixtures; this result suggests that adjustments to the specimen conditioning requirements should be considered.

Analysis of Temperature-Dropping Characteristics of Warm Mix Asphalt and Hot Mix Asphalt

2012 ◽  
Vol 446-449 ◽  
pp. 2532-2536
Author(s):  
Shu Guang Hou
Keyword(s):  
Initial Temperature ◽  
Hot Mix Asphalt ◽  
Warm Mix Asphalt ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Different Types ◽  
Higher Temperature

In order to research the temperature-dropping characteristics of warm mix and hot mix asphalt, some rutting test panels are used as specimens to determine the temperature-dropping characteristics of hot mix asphalt（HMA）, warm mix asphalt（WMA） with mixing additive “LuBo” and warm mix asphalt with mixing additive “Sasobit” under the conditions with initial temperatures of 110°C and 130°C. The test results indicate that：the higher initial temperature，the higher temperature-dropping rate is. After 25min the temperatures of rutting test panels with initial temperatures of 110°C and 130°C are close to 66°C and 68°C. The temperature-dropping rates of different types of mixtures are not the same. When the initial temperature is 110°C, the temperature-dropping rate of hot mix asphalt is the highest, the temperature-dropping rate of warm mix asphalt added with “Sasobit” is in the middle, and the temperature-dropping rate of warm mix asphalt added with “LuBo” is the lowest. After 35min, the temperatures of the three types of asphalt mixtures had fallen by 53°C， 51°C and 49°C separately.

Estimating Results of a Proposed Simple Performance Test for Hot-Mix Asphalt from Superpave Gyratory Compactor Results

2005 ◽  
Vol 1929 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Ahmed F. Faheem ◽  
Hussain U. Bahia ◽  
Hossein Ajideh
Keyword(s):  
Performance Test ◽  
Test Procedure ◽  
Asphalt Mixtures ◽  
Strongly Correlated ◽  
Flow Number ◽  
Traffic Loading ◽  
Superpave Gyratory Compactor ◽  
The Stability ◽  
Work Done ◽  
Pavement Service Life

This study intended to use the Superpave® gyratory compactor (SGC) as a basis for estimating the stability of asphalt mixtures as a surrogate for proposed method for the simple performance test. Several asphalt mixtures were produced with varying aggregate sources, asphalt contents, and gradations. Every mixture was compacted with the SGC and evaluated with the repeated compression test procedure for rutting measurements recommended by NCHRP Project 9–19 and the AASHTO 2002 pavement design manual to evaluate whether the results from the SGC can be related to the rutting of mixtures. Densification curves produced by the SGC were used to determine the volumetric properties besides the calculation of the traffic densification index (TDI), which represents the densification experienced by traffic loading during pavement service life. The traffic force index (TFI) was also calculated with a special accessory added to the SGC during compaction (the pressure distributor analyzer). The TFI represents the work done by the traffic to densify the mixture. Results from the mixture rutting tests were used to estimate the flow number (FN). The FN, an important mixture property, is shown to have a strong correlation to the TFI. The TFI was also found to be strongly correlated with the TDI and gives an opportunity to estimate the mixture resistance to compaction forces with the use of its volumetric behavior. The main finding of the study is that the SGC appears to give information that can be used to characterize the stability of the mixtures. Such information could be used as an initial screening criterion to select mixtures for various traffic levels.

Performance of Asphalt Rejuvenators in Hot-Mix Asphalt Containing Recycled Asphalt Shingles

2017 ◽  
Vol 2633 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Max A. Aguirre ◽  
Marwa M. Hassan ◽  
Sharareh Shirzad ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper
Keyword(s):  
Hot Mix Asphalt ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Strain Energy Release ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Test Results ◽  
Recycled Asphalt ◽  
Recycled Asphalt Shingles ◽  
Asphalt Shingles

The use of recycled asphalt shingles (RAS) in asphalt paving construction represents a sustainable approach to reduce virgin material consumption and negative environmental effects, as well as the cost of asphalt pavement. However, many challenges are yet to be addressed about the use of RAS in paving applications. This study evaluated the effect of the incorporation of postconsumer waste shingles and rejuvenators on the performance of hot-mix asphalt. Four asphalt rejuvenators—one bio-oil and three synthetic oils—were evaluated. A set of laboratory tests was conducted to characterize the performance of asphalt mixtures against permanent deformation and fatigue cracking. The addition of 5% RAS showed an improvement in permanent deformation when compared with a conventional mixture with no RAS. Yet the addition of asphalt rejuvenator products slightly decreased the performance against permanent deformation. On the basis of Hamburg wheel-tracking device test results, the addition of RAS did not adversely affect moisture resistance. Yet semicircular bending test results showed that the asphalt mixtures that contained asphalt rejuvenators had a lower critical strain energy release rate than the minimum threshold value (0.5 kJ/m2), which indicated a greater susceptibility to intermediate-temperature cracking.

scholarly journals Application of WMA Technology to Bituminous Base Course Mixes

2018 ◽  
Vol 13 (2) ◽  
pp. 94-103 ◽  
Author(s):  
Rajan Choudhary ◽  
Asho Julaganti ◽  
Abhinay Kumar ◽  
Dipak Arjun Ugale
Keyword(s):  
Hot Mix Asphalt ◽  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Strength Ratio ◽  
Test Results ◽  
Base Course ◽  
Marshall Stability ◽  
Rheological Test ◽  
Stability Results ◽  
Different Doses

Warm Mix Asphalt, due to lower mixing and compaction temperatures, provides some engineering benefits over conventional Hot Mix Asphalt. In this study, an attempt is made to assess the viability of using Warm Mix Asphalt technology in bituminous base courses. An organic wax-based Warm Mix Asphalt additive was used in this study to produce Dense Bituminous Macadam, a commonly used bituminous base course mix in India. Experimental variables included three additive contents and four mixing temperatures. Rheological properties of binder modified with different doses of additive were examined. In all, twelve Warm Mix Asphalt Dense Bituminous Macadam mix types were prepared, evaluated and compared with Hot Mix Asphalt Dense Bituminous Macadam (control) mix. Rheological test results showed the addition of wax-based additive improved stiffness and resistance against permanent deformation of the base binder. Tensile Strength Ratio and retained Marshall Stability results indicated that Warm Mix Asphalt Dense Bituminous Macadam mixes were resistant to moisture-induced damage.

scholarly journals Influence of compaction temperature on the properties of Marshall specimens

2015 ◽  
Vol 10 (4) ◽  
pp. 309-315 ◽  
Author(s):  
Ivica Androjić ◽  
Sanja Dimter
Keyword(s):  
Mechanical Properties ◽  
Structural Design ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Maximum Density ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Compaction Temperature ◽  
Asphalt Mix ◽  
Very High

Compaction of hot mix asphalt is influenced by several factors; some related to the environment, some determined by mix and structural design and some by contractor during construction. The temperature of asphalt mixture has the biggest influence on the compaction of asphalt mixtures and their properties. The temperature of asphalt mixture affects viscosity of bitumen and achievement of the maximum density of asphalt mixture. This paper describes a laboratory study on the effects of different installation temperatures on the physico-mechanical properties of specimens of asphalt mixtures: stability, Marshall Quotient (stiffness), density, voids and voids filled with asphalt. By regression analysis of the test results the correlation of certain properties of asphalt mix and compaction temperatures was established. For all the models observed, the coefficients of determination are very high and indicate very solid links. The obtained research results indicate a pronounced effect of compaction temperature on each tested property of asphalt mix.

scholarly journals Effect of SBS Polymer and Anti-stripping Agents on the Moisture Susceptibility of Hot and Warm Mix Asphalt Mixtures

2017 ◽  
Vol 3 (10) ◽  
pp. 987 ◽  
Author(s):  
Hamed Omrani ◽  
Ali Reza Ghanizadeh ◽  
Amin Tanakizadeh
Keyword(s):  
Tensile Strength ◽  
Hydrated Lime ◽  
Warm Mix Asphalt ◽  
Primary Objective ◽  
Asphalt Mixtures ◽  
Strength Ratio ◽  
Test Results ◽  
Moisture Susceptibility ◽  
Modified Asphalt ◽  
Polymer Modified Asphalt

The primary objective of this study is exploring the moisture susceptibility of unmodified and SBS-modified hot and warm mix asphalt mixtures. To this end, two different WMA additives including Aspha-min and Sasobit were employed to fabricate WMA specimens. The moisture susceptibility of warm polymer modified asphalt (WPMA) mixes was evaluated using modified Lottman test at 25°C according to AASHTO standard (T 283). In addition, the effect of different percentages of hydrated lime (from 0% to 2%) and Zycosoil (from 0% to 0.1%) as anti-stripping additives on the moisture susceptibility of the mixtures was explored. Based on the ITS test results, WPMA prepared with Sasobit additive and polymer modified asphalt (PMA) mixes satisfied the desirable tensile strength ratio (TSR) (above 80%) but Aspha-min WPMA mixes had TSR lower than 80%.

scholarly journals Hidden Service Website Response Fingerprinting Attacks Based on Response Time Feature

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Yitong Meng ◽  
Jinlong Fei
Keyword(s):  
Response Time ◽  
Performance Test ◽  
Classification Performance ◽  
Small Scale ◽  
Test Results ◽  
Open World ◽  
Closed World ◽  
Traffic Level ◽  
Active Attacks ◽  
Encrypted Traffic

It has been shown that website fingerprinting attacks are capable of destroying the anonymity of the communicator at the traffic level. This enables local attackers to infer the website contents of the encrypted traffic by using packet statistics. Previous researches on hidden service attacks tend to focus on active attacks; therefore, the reliability of attack conditions and validity of test results cannot be fully verified. Hence, it is necessary to reexamine hidden service attacks from the perspective of fingerprinting attacks. In this paper, we propose a novel Website Response Fingerprinting (WRFP) Attack based on response time feature and extremely randomized tree algorithm to analyze the hidden information of the response fingerprint. The objective is to monitor hidden service website pages, service types, and mounted servers. WRFP relies on the hidden service response fingerprinting dataset. In addition to simulated website mirroring, two different mounting modes are taken into account, the same-source server and multisource server. A total of 300,000 page instances within 30,000 domain sites are collected, and we comprehensively evaluate the classification performance of the proposed WRFP. Our results show that the TPR of webpages and server classification remain greater than 93% in the small-scale closed-world performance test, and it is capable of tolerating up to 10% fluctuations in response time. WRFP also provides a higher accuracy and computational efficiency than traditional website fingerprinting classifiers in the challenging open-world performance test. This also indicates the importance of response time feature. Our results also suggest that monitoring website types improves the judgment effect of the classifier on subpages.

Viscoelastic Properties of Field-Aged Cores

2013 ◽  
Vol 723 ◽  
pp. 551-556
Author(s):  
Ling Meng
Keyword(s):  
Asphalt Concrete ◽  
Viscoelastic Properties ◽  
Hot Mix Asphalt ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Tension Test ◽  
Asphalt Mixtures ◽  
Direct Tension ◽  
Direct Tension Test ◽  
Aged Asphalt

Nowadays, engineers begin to pay more attention on field-aged asphalt concrete cores because they have more reality than the lab-made cores and the results can tell what happened to the pavement. However, it is not accurate to estimate the full asphalt mixture because as usual the pavement engineers can only extract the binder from it, not the mixture. Now there is a newly developed way to analysis the data more accurately using the Direct Tension Test. Because the field aged asphalt mixtures are not aged uniformly with the pavement depth because of various reasons, there is a modulus gradient going through deeply through the asphalt layer and usually the stiffest layer is the surface because normally the surface is more aged. A method has been developed to analysis this behavior. Tests are both taken on field cores which are Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA). During the research, the authors found that it is both applicable for all the field cores. More information about this method and tests are detailed in the following paragraphs.

scholarly journals Effect of Aramid Fibers on Balanced Mix Design of Asphalt Concrete

CivilEng ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 21-34
Author(s):  
Hossein Noorvand ◽  
Samuel Castro Brockman ◽  
Michael Mamlouk ◽  
Kamil Kaloush
Keyword(s):  
Asphalt Concrete ◽  
Performance Test ◽  
Fatigue Cracking ◽  
Mix Design ◽  
Test Results ◽  
Aramid Fibers ◽  
Flow Number ◽  
Good Tool ◽  
Test Ideal ◽  
Dispersion Test

Fiber-reinforced asphalt concrete (FRAC) was tested using limestone, PG 64-22 binder, and 20% reclaimed asphalt pavement (RAP). After mixing fibers with different lengths and dosages, they were extracted and recovered to evaluate their dispersion in the FRAC. The uniaxial fatigue test, IDEAL CT test, and flow number test were performed on FRAC with different fiber lengths and asphalt contents. The balanced mix design (BMD) approach was then used to analyze the uniaxial and flow number test results in order to evaluate the effect of aramid fibers on fatigue and rutting resistance of the pavement. The dispersion test showed that the 19 mm and 10 mm aramid fibers at a dosage rate of 0.5 g/kg provided the best dispersion. The 19 mm fibers showed better performance test results than the 10 mm and 38 mm fibers. The BMD approach provided ranges of asphalt contents to produce mixes with certain resistances to fatigue and rutting. The BMD approach also demonstrated the effect of fibers with different lengths on increasing the resistance to fatigue and rutting. The study concluded that the 19 mm fibers with a dosage of 0.5 g/kg produce best results. The BMD approach is a good tool that can be used to refine the mix ingredients, including additives such as fibers, in order to optimize pavement resistance to various distresses such as fatigue cracking and rutting.

scholarly journals Environmental Impact Assessment of Different Warm Mix Asphalts

2021 ◽  
Vol 13 (21) ◽  
pp. 11869
Author(s):  
Anda Ligia Belc ◽  
Adrian Ciutina ◽  
Raluca Buzatu ◽  
Florin Belc ◽  
Ciprian Costescu
Keyword(s):  
Environmental Impact ◽  
Hot Mix Asphalt ◽  
Raw Materials ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Organic Additive ◽  
Asphalt Mixtures ◽  
Organic Additives ◽  
Chemical Additive ◽  
Production Phase

Within the last decade, much attention has been focused on determining viable techniques for producing sustainable asphalt mixtures and minimizing fuel use and greenhouse gas emissions. Thus, warm mix asphalt (WMA) has become a topic of significant interest among road specialists as it offers a potential solution for reducing the environmental impact of the asphalt mixtures due to the decreased temperatures they require for mixing and compaction compared to hot mix asphalt (HMA). The present study is focused on the Life Cycle Assessment (LCA), according to a “Cradle-to-Gate” approach, of hot mix asphalt and warm mix asphalt prepared with locally available materials and different warm mix additives such as organic additives, chemical additive, and synthetic zeolite. For the analysis of the environmental impact of the warm mix asphalts was used a dedicated software for modeling and evaluating the LCA. The WMA prepared with chemical additive or organic additive led to a decrease of the environmental impact, in the production phase, compared to HMA. The study reveals that the raw materials extraction has the greatest impact on the environment in all studied cases, followed by the actual production phase of the asphalt mixture. For WMA produced with additives there was a decrease in the global impact on the environment compared to HMA.

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