Investigation of Moisture Susceptibility of Warm-Mix Asphalt Mixes through Laboratory Mechanical Testing

2012 ◽  
Vol 2295 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Wenyi Gong ◽  
Mingjiang Tao ◽  
Rajib B. Mallick ◽  
Tahar El-Korchi
Keyword(s):  
Fracture Energy ◽  
Creep Compliance ◽  
Resilient Modulus ◽  
Warm Mix Asphalt ◽  
Energy Ratio ◽  
Concrete Pavements ◽  
Moisture Susceptibility ◽  
Asphalt Mixes ◽  
Conditioning Process ◽  
Damage Indicators

Moisture can lead to serious damage and failures in hot-mix asphalt concrete pavements. This is an even greater concern for warm-mix asphalt because the much lower production temperatures may not completely dry the aggregates. In this Maine Department of Transportation study, the use of fracture energy parameters was evaluated to determine the influence of incomplete drying of mixes on their mechanical properties. Fracture energy–based parameters [energy ratio (ER); ratio of energy ratio (RER)] were determined from the following testing of mixes with fully and partially dried aggregates, some of which were subjected to moisture conditioning: resilient modulus, creep compliance, and indirect tensile strength (ITS) at 5°C. The results indicate that (a) resilient modulus, creep compliance, and ITS were all affected by the presence of moisture in mixes; (b) the trend and the degree of influence of moisture for different mechanical parameters were different; (c) the moisture conditioning process caused larger decreases in modulus and ITS values than did incomplete drying of aggregates; however, the same moisture conditioning process caused much larger decreases in modulus and ITS in mixes prepared with incompletely dried aggregates than did the counterparts prepared with fully dried aggregates; and (d) fracture energy–based parameters (ER and RER) appeared to be more-distinctive moisture effect and damage indicators than are the other parameters.

scholarly journals Performance Evaluation of Hot Mix Asphalt with Different Proportions of RAP Content

2018 ◽  
Vol 34 ◽  
pp. 01026
Author(s):  
Ahmad Kamil Arshad ◽  
Haryati Awang ◽  
Ekarizan Shaffie ◽  
Wardati Hashim ◽  
Zanariah Abd Rahman
Keyword(s):  
Hot Mix Asphalt ◽  
Resilient Modulus ◽  
Design Method ◽  
Asphalt Pavement ◽  
Cost Savings ◽  
Volumetric Analysis ◽  
Public Works ◽  
Asphalt Binders ◽  
Moisture Susceptibility ◽  
Asphalt Mixes

Reclaimed Asphalt Pavement (RAP) is old asphalt pavement that has been removed from a road by milling or full depth removal. The use of RAP in hot mix asphalt (HMA) eliminates the need to dispose old asphalt pavements and conserves asphalt binders and aggregates, resulting in significant cost savings and benefits to society. This paper presents a study on HMA with different RAP proportions carried out to evaluate the volumetric properties and performance of asphalt mixes containing different proportions of RAP. Marshall Mix Design Method was used to produce control mix (0% RAP) and asphalt mixes containing 15% RAP, 25% RAP and 35% RAP in accordance with Specifications for Road Works of Public Works Department, Malaysia for AC14 dense graded asphalt gradation. Volumetric analysis was performed to ensure that the result is compliance with specification requirements. The resilient modulus test was performed to measure the stiffness of the mixes while the Modified Lottman test was conducted to evaluate the moisture susceptibility of these mixes. The Hamburg wheel tracking test was used to evaluate the rutting performance of these mixes. The results obtained showed that there were no substantial difference in Marshall Properties, moisture susceptibility, resilient modulus and rutting resistance between asphalt mixes with RAP and the control mix. The test results indicated that recycled mixes performed as good as the performance of conventional HMA in terms of moisture susceptibility and resilient modulus. It is recommended that further research be carried out for asphalt mixes containing more than 35% RAP material.

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.

Evaluation of Warm Mix Asphalt Performance with High RAP Content

2015 ◽  
Vol 73 (4) ◽  
Author(s):  
Ahmad Kamil Arshad ◽  
Frag Ahmed Ma Kridan ◽  
Noor Azreena Kamaluddin ◽  
Ekarizan Shafie
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Warm Mix Asphalt ◽  
Beam Specimen ◽  
Moisture Susceptibility ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Indirect Tensile ◽  
Asphalt Performance ◽  
Cost Of Materials

The pavement industry is currently forced to find alternative ways to produce asphaltic concrete with the  dwindling supply of new resources and the spiraling cost of materials. Warm Mix Asphalt (WMA) using reclaimed asphalt pavement (RAP) offers a sustainable solution to the problem by reducing energy requirements for production and the reuse of old pavement materials. The effects of warm mix asphalt additive (Sasobit) on mixes containing different percentages of RAP were investigated in the laboratory. Three different concentrations of RAP (30%, 40% and 50%) with 1.5% Sasobit by weight of binder were added, and Marshall method was used to produce all samples investigated. Two different mixing and compaction temperatures were used, 155°C and 135°C for mixing and 135°C and 120°C  for compaction. The performance of the mixes in terms of stiffness and moisture damage were investigated by carrying out the Indirect Tensile Resilient Modulus Test (ASTM D4123) and moisture susceptibility test (ASTM D 4867). The results obtained showed that there were no substantial differences in volumetric properties, stability and stiffness values of reclaimed mixes than the control mix (conventional hot mix asphalt). In addition, all the mixes investigated achieved the required minimum TSR of 80%. Measured rut depth using the Asphalt Pavement Analyser (APA) device and fatigue cycles to failure using beam specimen indicated that the mixes performed similar to or better than the control mix. The results showed that warm mix asphalt using sasobit-additive and containing high percentages of RAP could be a sustainable alternative to the conventional HMA mix.  

scholarly journals Rutting and moisture-induced damage potential of foamed warm mix asphalt (WMA) containing RAP

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Mohammad Ashiqur Rahman ◽  
Rouzbeh Ghabchi ◽  
Musharraf Zaman ◽  
Syed Ashik Ali
Keyword(s):  
Asphalt Pavement ◽  
Warm Mix Asphalt ◽  
Environmental Benefits ◽  
Reclaimed Asphalt Pavement ◽  
Chemical Additives ◽  
Flow Number ◽  
Damage Potential ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Wheel Tracking

AbstractDespite significant economic and environmental benefits, performance of warm mix asphalt (WMA) containing reclaimed asphalt pavement (RAP) remains a matter of concern. Among the current WMA technologies, the plant foaming technique (called “foamed WMA” in this study) has gained the most attention, since it eliminates the need for chemical additives. In the present study, the laboratory performance, namely rutting and moisture-induced damage potential of foamed WMA containing RAP were evaluated and compared with those of similar hot mix asphalt (HMA) containing identical amount of RAP. Dynamic modulus, Hamburg wheel tracking (HWT) and flow number tests were performed to assess the rutting resistance of the mixes. Also, stripping inflection point from HWT tests and tensile strength ratio after AASHTO T 283 and moisture induced sensitivity test (MIST) conditioning were used to evaluate the moisture-induced damage of asphalt mixes. It was found that MIST conditioning effectively simulates the moisture-induced damage and can capture the propensity of asphalt mixes to moisture damage more distinctly compared to AASHTO T 283 method due to application of cyclic loadings. The foamed WMA was found to exhibit higher rutting and moisture-induced damage potential due to lower mixing and compaction temperatures compared to HMA. However, the increase in RAP content was found to reduce rutting and moisture-induced damage potential for WMA. Therefore, the lower stiffness of foamed WMA may be compensated with the addition of stiffer binder from RAP.

Effects of Asphalt Foaming on Damage Characteristics of Foamed Warm Mix Asphalt

2021 ◽  
pp. 036119812199782
Author(s):  
Biswajit K. Bairgi ◽  
Md Amanul Hasan ◽  
Rafiqul A. Tarefder
Keyword(s):  
Permanent Deformation ◽  
Warm Mix Asphalt ◽  
Creep Recovery ◽  
Deformation Model ◽  
Contact Method ◽  
Moisture Susceptibility ◽  
Viscoelastic Continuum Damage ◽  
Foamed Asphalt ◽  
Flexural Beam ◽  
Wheel Tracking

In the asphalt foaming process, the foaming water content (FWC) controls the formation and characteristics of water bubbles. These water bubbles are expected to be expelled from the foamed warm mix asphalt (WMA) during mixing and compaction. However, foaming water may not be completely expelled, rather some of the microbubbles may be trapped in the foamed WMA even after compaction. These microbubbles, or undissipated water, can diffuse over time and cause damage to the foamed WMA. To this end, this study has determined the effects of foaming on the fatigue, moisture damage, and permanent deformation characteristics of foamed WMA. Foamed asphalt and mixtures were designed with varying FWCs and they were tested using linear amplitude sweep, multiple stress creep recovery, four-point flexural beam, and Hamburg wheel tracking tests. Primarily, asphalt foaming dynamics were assessed with a laser-based non-contact method. A simplified viscoelastic continuum damage concept and a three-phase permanent deformation model were used for damage evaluation. The study reveals that foaming softens the binder, which results in slightly higher rutting and moisture susceptibility, though an equivalent or slightly improved fatigue characteristic compared with the regular hot mix asphalt.

scholarly journals Characteristics of Warm Mix Asphalt Incorporating Coarse Steel Slag Aggregates

2021 ◽  
Vol 11 (8) ◽  
pp. 3708
Author(s):  
Adham Mohammed Alnadish ◽  
Mohamad Yusri Aman ◽  
Herda Yati Binti Katman ◽  
Mohd Rasdan Ibrahim
Keyword(s):  
Environmental Sustainability ◽  
Prediction Models ◽  
Hot Mix Asphalt ◽  
Steel Slag ◽  
Warm Mix Asphalt ◽  
Asphalt Mixes ◽  
Toxic Emissions ◽  
Comparable Performance ◽  
Different Temperatures ◽  
Production Temperature

The major goal of sustainable practices is to preserve raw resources through the utilization of waste materials as an alternative to natural resources. Decreasing the temperature required to produce asphalt mixes contributes to environmental sustainability by reducing energy consumption and toxic emissions. In this study, warm mix asphalt incorporating coarse steel slag aggregates was investigated. Warm mix asphalt was produced at different temperatures lower than the control asphalt mixes (hot mix asphalt) by 10, 20, and 30 °C. The performances of the control and warm mix asphalt were assessed through laboratory tests examining stiffness modulus, dynamic creep, and moisture sensitivity. Furthermore, a response surface methodology (RSM) was conducted by means of DESIGN EXPERT 11 to develop prediction models for the performance of warm mix asphalt. The findings of this study illustrate that producing warm mix asphalt at a temperature 10 °C lower than that of hot mix asphalt exhibited the best results, compared to the other mixes. Additionally, the warm mix asphalt produced at 30 °C lower than the hot mix asphalt exhibited comparable performance to the hot mix asphalt. However, as the production temperature increases, the performance of the warm mix asphalt improves.

Evaluation of Moisture Susceptibility Minimization Strategies for Warm-Mix Asphalt: Case Study

2016 ◽  
Vol 28 (2) ◽  
pp. 05015002 ◽  
Author(s):  
Lorena Garcia Cucalon ◽  
Fan Yin ◽  
Amy Epps Martin ◽  
Edith Arambula ◽  
Cindy Estakhri ◽  
...  
Keyword(s):  
Warm Mix Asphalt ◽  
Moisture Susceptibility

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

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