scholarly journals Laboratory performance and modelling behaviour of hot-mix asphalt with recycled crushed glass

2020 ◽  
Vol 62 (3) ◽  
Author(s):  
T B George ◽  
J K Anochie-Boateng ◽  
K J Jenkins
Keyword(s):  
Permanent Deformation ◽  
Constitutive Models ◽  
Hydrated Lime ◽  
Moisture Damage ◽  
Fine Aggregate ◽  
Moisture Susceptibility ◽  
Asphalt Mixes ◽  
Laboratory Performance ◽  
Deformation Properties ◽  
Asphalt Mix

In South Africa research is currently under way to determine the suitability of using locally available recycled crushed glass as a partial fine aggregate substitute in the production of asphalt mixes. This paper characterises the laboratory performance of a dense-graded asphalt wearing course mix consisting of 15% recycled crushed glass. The influence of selected antistripping additives on moisture susceptibility was specifically assessed as a variable in the performance evaluation of the glass-asphalt mix as follows: (a) the effect of 1% hydrated lime, (b) the effect of 0.5% liquid antistripping additive, and (c) the effect without the addition of antistripping additive. The effect of these variables on the moisture susceptibility of the glass-asphalt mix was evaluated using the tensile strength ratio parameter supported with a microscopic imaging analysis. Additionally, the stiffness and permanent deformation properties of the glass-asphalt mix that demonstrated optimum resistance to moisture damage was compared to the same mix without crushed glass. The performance properties were evaluated using the Huet-Sayegh model and a polynomial model respectively, which were used particularly to develop performance characterisation models for the glass-asphalt mix. The findings of this study revealed that an anti-stripping additive is essential to meet moisture susceptibility criteria and alleviate moisture damage in dense-graded glass-asphalt mixes. In particular, moisture susceptibility was improved using hydrated lime rather than the liquid antistripping additive. Furthermore, the selected constitutive models were able to effectively characterise the laboratory performance of both mixes, with the glass-asphalt mix demonstrating improved resistance to permanent deformation when compared with the conventional asphalt mix.

Effect of Increasing Sasobit on Permanent Deformation and Moisture Damage of Asphalt Mixes

2018 ◽  
Vol 877 ◽  
pp. 241-247 ◽  
Author(s):  
Fazal Haq ◽  
Arshad Hussain ◽  
Kamran Mushtaq
Keyword(s):  
Transportation Network ◽  
Permanent Deformation ◽  
Road Construction ◽  
Cost Effective ◽  
Moisture Damage ◽  
Moisture Susceptibility ◽  
Asphalt Mixes ◽  
The Road ◽  
Asphalt Mix ◽  
The Impact

Transportation network plays a substantial role in the everyday life of social beings. The preservation of this vast infrastructure needs appropriate and cost-effective design techniques, which depends upon the selection and proportion of binder and aggregate. With the passage of time, as compared to HMA (Hot Mix Asphalt), WMA (Warm mix asphalt) has become extreme prevalent in the road construction industry, because WMA offers the opportunity of production asphalt mix at a reduced temperature than conventionally used for HMA, hence saving energy, cutting CO2 emission and improve environmental quality. This study aims to assess the impact of sasobit (an organic WMA additive) on permanent deformation and moisture susceptibility of asphalt mixes. Under the scope of this paper, the authors have added three percentages of sasobit that is 1%, 2% and 3% to check the effect of increasing sasobit percentage on rutting and moisture damage of asphalt mixes. In summary, rut depth of WMA as obtained from Hamburg Wheel Tracker Device (HWTD) slightly decreased from that of HMA, while rut depth at 1% and 2% was even less than that of 3% sasobit. A slight increase in moisture damage as compared to control mix was observed by adding sasobit, as illustrated by decreased Tensile Strength Ratios TSR.

Mechanistic Evaluation of Hydrated Lime in Hot-Mix Asphalt Mixtures

2000 ◽  
Vol 1723 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Louay N. Mohammad ◽  
Chris Abadie ◽  
Rana Gokmen ◽  
Anand J. Puppala
Keyword(s):  
Resilient Modulus ◽  
Permanent Deformation ◽  
Hydrated Lime ◽  
Engineering Properties ◽  
Deformation Characteristics ◽  
Asphaltic Concrete ◽  
Moisture Susceptibility ◽  
Limestone Aggregate ◽  
Concrete Mixtures ◽  
Mineral Fillers

Permanent deformation and moisture damage are common distresses found in pavements today. The use of mineral fillers such as hydrated lime is known to provide a decrease in moisture susceptibility. In many cases, mineral fillers will also increase the mixture stiffness. Conventional asphaltic concrete mixtures and mixtures modified with hydrated lime were evaluated for their fundamental engineering properties as defined by indirect tensile strength and strain, permanent deformation characteristics, resilient modulus, and fatigue resistance. A typical Louisiana low-volume dense-graded mixture was used. The test factorial included two aggregate types (limestone and gravel) and two asphalt cement types (a conventional AC-30 and one modified with styrene-butadiene polymer). The results indicated that the addition of hydrated lime as mineral filler improved the permanent deformation characteristics and fatigue endurance of the asphaltic concrete mixtures. This improvement was particularly apparent at higher testing temperatures with mixes containing polymer-modified asphalt and limestone aggregate.

Laboratory Investigation of Moisture Damage in Asphalt Rubber Hot Mixes Using Warm Mix Technology

2012 ◽  
Vol 598 ◽  
pp. 438-443
Author(s):  
Jing Hui Liu
Keyword(s):  
Tensile Strength ◽  
Laboratory Investigation ◽  
Moisture Damage ◽  
Crumb Rubber ◽  
Warm Mix Asphalt ◽  
Moisture Susceptibility ◽  
Asphalt Mixes ◽  
Testing Procedures ◽  
Asphalt Rubber ◽  
Knowledge Area

The advantages of using asphalt rubber pavement strategies have been validated by many research efforts. However, the most obvious disadvantage of asphalt rubber hot mix is requiring a higher mix and placement temperature in order to obtain adequate workability, which results in higher energy requirements and asphalt easy ageing. By utilizing Warm Mix Asphalt(WMA) technology the temperature requirements of the asphalt rubber hot mix can be reduced significantly. Warm mix asphalt (WMA) is the name given to certain technologies that reduce the production and placement temperatures of asphalt mixes. Asphalt Rubber Hot Mix of containing Warm Mix technology is a very promising technology whether in energy saving or improving pavement performance. One of the main concentrations of crumb rubber mix is now on the moisture damage evaluation due to WMA additives. In this study, the objective was to conduct a laboratory investigation of moisture damage in Warm Rubber Mix Asphalt(WRMA). Currently, there are no standards or laboratory test data to support the knowledge area on the susceptibility of asphalt rubber mixtures to moisture damage. The widely accepted testing procedures i.e. indirect tensile strength (ITS) and tensile strength ratio (TSR) were performed to determine the moisture susceptibility of the mixtures.

Laboratory Investigation of the Performance Evaluation of Fiber-Modified Asphalt Mixes in Cold Regions

2020 ◽  
Vol 2674 (7) ◽  
pp. 323-335
Author(s):  
Luis Alberto Perca Callomamani ◽  
Leila Hashemian ◽  
Katrina Sha
Keyword(s):  
Low Temperatures ◽  
Polymer Fibers ◽  
Cost Comparison ◽  
Moisture Susceptibility ◽  
Traffic Loading ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
Reliable Source ◽  
Asphalt Mix ◽  
Source Of Information

Thermal cracking of pavement is caused by contraction of the asphalt layer at low temperatures, when tensile stresses build up to a critical point at which a crack is formed. The cracks formed then propagate under traffic loading conditions. Freeze-thaw cycles accelerate crack propagation and deterioration of the asphalt layer, and can also lead to the formation of more severe distresses such as potholes. Fibers have attracted increasing attention in the asphalt industry for use as asphalt concrete modifiers. The addition of fibers to hot mix asphalt (HMA) results in a composite material that has a higher tensile strength, along with the ability to absorb greater energy during the fracture process. The fibers within the material also act as a barrier preventing the formation and propagation of cracks in the asphalt mix. This research evaluates the effectiveness of adding polymer fibers to HMA to increase both its resistance to cracking at intermediate and low temperatures, and its rutting resistance and moisture susceptibility at high temperatures. For this purpose, three different types of polymer fibers: aramids, polyethylene terephthalate (PET), and polyacrylonitrile (PAN), were added to conventional HMA mixes. The resulting samples were compacted, and their mechanical properties were compared with conventional HMA in the laboratory. At the end of the paper, a material cost comparison is provided as a reliable source of information when selecting materials to fulfill minimum industry specifications.

Utilization of Gneiss in Asphalt Concrete Mixtures

2009 ◽  
Vol 620-622 ◽  
pp. 1-4 ◽  
Author(s):  
Shao Peng Wu ◽  
De Ming Hu ◽  
Ling Pang ◽  
Hong Wang
Keyword(s):  
Los Angeles ◽  
Physical Properties ◽  
Hydrated Lime ◽  
Fine Aggregate ◽  
Moisture Susceptibility ◽  
Los Angeles Abrasion ◽  
Concrete Mixtures ◽  
Low Temperature Cracking ◽  
Flakiness Index ◽  
Marshall Stability

Construction of the pavement has consumed a huge amount of high grade aggregates, such as basalt, limestone etc. In some region, these aggregates are very scarce and have to be produced and transported from far aggregate quarries which would cause the waste of energy and resources as well as the increase of cost. Large quantities of gneiss exist in China, the use of gneiss as aggregates might help meet the highway constructing demands and save. In this paper, the feasibility is analyzed with respect to different aspects. Physical properties of gneiss aggregate were evaluated using Los Angeles abrasion, specific gravity and flakiness index. Mixture properties were characterized in terms of Marshall stability, moisture susceptibility, soak wheel track and low temperature cracking resistance property. Experiment results indicate that the physical properties of gneiss aggregates can satisfy the related specifications and these gneiss materials as aggregates can be used in asphalt pavement. Results also show that the optimal gradation component of the mixture consists of the gneiss as coarse aggregate and the limestone as fine aggregate. The use of hydrated lime can improve the moisture susceptibility of the mixtures containing gneiss aggregates.

scholarly journals Evaluation of Moisture Sensitivity Performance of Stone Mastic Asphalt Mixes with Additional Filler: A Laboratory Comparison of Dry and Wet Mixing Methods

2021 ◽  
Author(s):  
Altan CETIN
Keyword(s):  
Fly Ash ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Filler Materials ◽  
Fine Aggregate ◽  
Moisture Susceptibility ◽  
Technical Specifications ◽  
Class C ◽  
Hot Mixed Asphalt ◽  
Class F

Gap-graded mixtures are one of the areas of improving the permanent deformation strength of hot-mixed asphalt mixtures. Additional filler materials can be needed due to the high bitumen amount and the less fine aggregate amount in the mixture. In this study, the effects of filler additives on moisture susceptibility of the gap-graded hot-mixed asphalt mixtures and mixing methods are investigated. Filler additives such as class C and class F fly ashes and hydrated lime are used 0.5 %, 1.0 %, 2.0 %, and 4 % of the total weight of mixture instead of mineral filler. Design mixtures are prepared according to the Turkish Highway Technical Specifications (THTS). To determine the effect of mixing methods, dry and wet (slurry) methods are used to mix the filler materials. Modified Lottman method (AASHTO T283) are used to determine the moisture susceptibility. An indirect tensile strength test is the measurement of bitumen film thickness which is also conducted. Test results showed that class C fly ash is significantly improved the moisture susceptibility of mixtures. While the slurry method does not give the expected improvement on class C fly ash added mixtures, it shows a positive effect on class F fly ash and hydrated lime added mixtures.

scholarly journals Properties of Epoxy-Asphalt Pavement Mixture for Bridge Decks

2018 ◽  
Vol 21 (1) ◽  
pp. 20 ◽  
Author(s):  
Amjad H. Albayati ◽  
Esraa T. Al-Azawee
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Moisture Damage ◽  
Accumulation Coefficient ◽  
Asphalt Mixes ◽  
Asphalt Cement ◽  
Epoxy Asphalt ◽  
Design And Construction

Improving the ability of asphalt pavement to survive the heavily repeated axle loads and weathering challenges in Iraq has been the subject of research for many years. The critical need for such data in the design and construction of more durable flexible pavement in bridge deck material is paramount. One of new possible steps is the epoxy asphalt concrete, which is classified as a superior asphalt concrete in roads and greatly imparts the level of design and construction. This paper describes a study on 40-50 penetration graded asphalt cement mixed with epoxy to produce asphalt concrete mixtures. The tests carried out are the Marshall properties, permanent deformation, flexural fatigue cracking and moisture damage. Epoxy asphalt mixes performed better on resistance to fatigue and permanent deformation. They also performed significantly better on low-temperature properties and resistance to moisture damage. The addition of 30 percent of epoxy (by weight of asphalt cement) resulted in increase of Marshall stability by 39.8 percent, improve the tensile strength ratio by 22.9 percent, lowering both the rate of permanent deformation by 26.8 percent and the fatigue accumulation coefficient by 53.5 percent, in comparison with control HMA. Based on the above findings, it is recommended to use epoxy asphalt mixes as an optimal material for paving bridges deck in Iraq since it showed good prospects for this application due to the valuable performance and durability improvement.

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