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 characterization of recycled crumb-rubber-modified asphalt mixture after extended aging

2008 ◽  
Vol 35 (11) ◽  
pp. 1308-1317 ◽  
Author(s):  
Soon-Jae Lee ◽  
Hakseo Kim ◽  
Chandra K. Akisetty ◽  
Serji N. Amirkhanian
Keyword(s):  
Tensile Strength ◽  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Accelerated Aging ◽  
Crumb Rubber ◽  
Moisture Susceptibility ◽  
Testing Procedures ◽  
Laboratory Characterization ◽  
Significant Difference

This paper presents a limited study that characterizes the recycling of artificially aged crumb-rubber modified (CRM) mixtures depending on their recycling percentage and aggregate type. Eight mixtures [six recycled mixtures containing rubberized reclaimed asphalt pavement (RAP) and two control virgin mixtures] were designed and tested. Two types of aggregates were used in this research project. The rubberized RAP used in the study was artificially aged in the laboratory using an accelerated aging processes. The percentages of the RAP, by total weight of the mix, incorporated into the recycled mixtures were 15%, 25%, and 35%. Evaluation of all mixtures included the following testing procedures: tensile strength ratio (TSR), asphalt pavement analyzer (APA), resilient modulus, and indirect tensile strength (ITS) after long-term oven aging. The results from this study showed that (i) the recycled aged CRM mixtures (with 15%, 25%, and 35% rubberized RAP) can satisfy the current Superpave mixture requirements, including moisture susceptibility and rutting resistance, and (ii) in general, there was no significant difference between the control and the recycled CRM mixtures for the properties evaluated in this study.

Laboratory Assessment of Workability of Asphalt Rubber Hot Mixes Using Warm Mix Technology

2012 ◽  
Vol 193-194 ◽  
pp. 452-457 ◽  
Author(s):  
Meng Yun Huang ◽  
Jing Hui Liu ◽  
Xi Zhang ◽  
Dan Ni Li
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Laboratory Assessment ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Road ◽  
Asphalt Rubber ◽  
Synergy Effects ◽  
Save Energy

Using the waste crumb rubber modified asphalt to pave the road surface could reduce cost and save energy. However，in order to obtain adequate workability, the mixing temperature and compaction temperature of rubberized asphalt binder and its mixture is much higher than those of conventional asphalt mixtures. Warm Mix Asphalt (WMA) is the name given to certain technologies that reduce the production and placement temperatures of asphalt mixes. One of the main benefits advertised is the increased workability at conventional and lower compaction temperatures with the WMA addition. This paper evaluates whether there are any synergy effects of using warm mix technologies and Asphalt Rubber(AR) hot mixes. This paper summarizes a lab research to evaluate the workability of Asphalt Rubber hot mixes containing warm mix technologies. Both asphalt binder and asphalt mixture were evaluated and compared. The research suggests that combining WMA technology with Asphalt Rubber mixtures is a win-win.

scholarly journals Moisture Susceptibility of Sustainable Warm Mix Asphalt

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Amjad H. Albayati ◽  
Hasan M. Al-Mosawe ◽  
Abbas A. Allawi ◽  
Nazar Oukaili
Keyword(s):  
Cement Content ◽  
Design Method ◽  
Future Generation ◽  
Moisture Damage ◽  
Warm Mix Asphalt ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Moisture Susceptibility ◽  
Asphalt Cement ◽  
Indirect Tension

Sustainable pavements are pavements that meet the requirements of present generation without influencing the capability of the future generation to meet their needs. One of the problems of the warm mix asphalt is that it has low resistance to moisture damage; therefore, the aim of this research paper is to study the possibility of producing more durable warm mixes against the moisture damage with the use of recycled concrete aggregate (RCA) which has not been studied before. Six replacement rates (0, 20, 40, 60, 80, and 100%) for the coarse version aggregate (VA) with RCA were studied. The Marshall mix design method was used to determine the optimum asphalt cement content for each replacement rate. Thereafter, specimens with the optimum asphalt cement content were prepared and tested in the indirect tension test to evaluate their moisture susceptibility. The results revealed that the mixes with higher percentage of RCA possess higher optimum asphalt content. Moreover, an improvement of 13 and 28% in Marshall stability and tensile strength ratio (TSR), respectively, was obtained in case that the VA was entirely replaced by the RCA.

scholarly journals Effect of Polypropylene Fibers on moisture Susceptibility of Warm Mix Asphalt

2021 ◽  
Vol 7 (6) ◽  
pp. 988-997
Author(s):  
Sura Fawzi Mohammed ◽  
Mohammed Qadir Ismael
Keyword(s):  
Tensile Strength ◽  
Asphalt Mixture ◽  
Material Design ◽  
Warm Mix Asphalt ◽  
Asphalt Pavements ◽  
Strength Ratio ◽  
Polypropylene Fibres ◽  
Moisture Susceptibility ◽  
Asphalt Cement ◽  
Energy Saving Process

Warm Mix Asphalt (WMA) is a modern energy-saving process that uses environmentally friendly materials, has lower mixing and compaction temperatures, and uses less energy and releases less contaminants than conventional hot mix asphalt. Moisture damage poses one of the main challenges of the material design in asphalt pavements. During its design life, the asphalt pavement is exposed to the effect of moisture from the surrounding environment. This research intends to investigate the role of the polypropylene fibres for modifying the moisture susceptibility for the WMA by using different percentages of polypropylene (namely 2, 4, and 6%) by weight of the binder of the control mixture (WMA). In this paper, the physical characteristics of the asphalt cement, Marshall properties, Tensile Strength Ratio (TSR) and Index of Retained Strength (IRS) were determined to establish the effect of the polypropylene on the moisture susceptibility of the WMA. The results displayed that the modification of the AC with polypropylene caused an increase in the optimum asphalt content by 1.03, 3.09, and 11.3%, with the addition of 2, 4 and 6% of the P.P., respectively. The moisture resistance of the asphalt mixture was enhanced by adding the P.P., according to the rise in the Tensile Strength Ratio (TSR) and Index of Retained Strength (IRS) values. The TSR value showed 9.4, 18.2 and 19.5% increase when the P.P. increased from 0.00 to 0.02, 0.04, and 0.06, respectively; besides, the IRS showed improvement with the addition of the P.P. to the WMA. Doi: 10.28991/cej-2021-03091704 Full Text: PDF

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%.

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.

Experimental Evaluation of Moisture Damage and Rutting Resistance for SBS Modified Warm Mix Asphalt Incorporating Recycled Asphalt Concrete

2021 ◽  
Vol 904 ◽  
pp. 464-469
Author(s):  
Mohammed Qadir Ismael
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Experimental Evaluation ◽  
Asphalt Binder ◽  
Stability Index ◽  
Warm Mix Asphalt ◽  
Recycled Asphalt ◽  
Moisture Susceptibility ◽  
Rutting Resistance ◽  
Styrene Butadiene

The efforts embedded in this paper have been devoted to designing, preparing, and testing warm mix asphalt (WMA) mixtures and comparing their behavior against traditional hot mix asphalt mixtures. For WMA preparation, the Sasobit wax additive has been added to a 40/50 asphalt binder with a concentration of 3%. An experimental evaluation has been performed by conducting the Marshall together with volumetric properties, indirect tensile strength, and wheel tracking tests to acquire the tensile strength ratio (TSR), retained stability index (RSI), and rut depth. It was found that the gained benefit of reduction in mixing and compaction temperatures was reversely associated with a noticeable decline in Marshall properties and moisture susceptibility indices designated by TSR, and RSI, and even the rut resistance was adversely affected. Modification of WMA mixtures by 3% of Styrene-Butadiene-Styrene (SBS) polymer coupled with replacement of virgin ingredient by 50% of recycled asphalt concrete granted a 20% and 15% growth in Marshall stability and tensile strength, respectively. Moreover, both TSR and IRS indices have risen to 87% and 90%, respectively associated with a 39% increase in rutting resistance ability.

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