scholarly journals Effects of Diatomite and SBS on Freeze-Thaw Resistance of Crumb Rubber Modified Asphalt Mixture

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Haibin Wei ◽  
Ziqi Li ◽  
Yubo Jiao
Keyword(s):  
Tensile Strength ◽  
Prediction Models ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Stiffness Modulus ◽  
Freeze Thaw ◽  
Stone Mastic Asphalt ◽  
Indirect Tensile ◽  
Air Void ◽  
Styrene Butadiene

Asphalt mixture is susceptible to moisture damage under the effect of freeze-thaw (F-T) cycles. In this paper, crumb rubber (CR) was used to modify stone mastic asphalt (SMA) and the effects of diatomite and styrene butadiene styrene (SBS) on antifreezing performances of crumb rubber modified SMA (CRSMA) were investigated. Regression analysis and modified grey model (MGM) were used to construct the prediction models for properties of modified mixtures. CRSMA, CR and diatomite modified SMA (CRDSMA), and CR and SBS modified SMA (CRSSMA) were prepared in laboratory, respectively. Process of F-T cycles was designed. Air void, indirect tensile strength (ITS), and indirect tensile stiffness modulus (ITSM) were measured to evaluate the antifreezing performances of CRSMA, CRDSMA, and CRSSMA. Results indicate that air voids increase with the increasing of F-T cycles. ITS and ITSM all decrease with the increasing of F-T cycles. The addition of diatomite and SBS can reduce the air void and improve the ITS and ITSM of CRSMA. CRSSMA presents the lowest air void, highest tensile strength, and largest stiffness modulus, which reveals that CRSSMA has the best F-T resistance among three different kinds of mixtures. Moreover, MGM (1, 2) models present more favorable accuracy in prediction of air void and ITS compared with regression ones.

scholarly journals Further Investigation on Damage Model of Eco-Friendly Basalt Fiber Modified Asphalt Mixture under Freeze-Thaw Cycles

2018 ◽  
Vol 9 (1) ◽  
pp. 60 ◽  
Author(s):  
Wensheng Wang ◽  
Yongchun Cheng ◽  
Guirong Ma ◽  
Guojin Tan ◽  
Xun Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Asphalt Mixtures ◽  
Splitting Tensile Strength ◽  
Stiffness Modulus ◽  
Freeze Thaw ◽  
Damage Characteristics ◽  
Indirect Tensile

The main distresses of asphalt pavements in seasonally frozen regions are due to the effects of water action, freeze-thaw cycles, and so on. Basalt fiber, as an eco-friendly mineral fiber with high mechanical performance, has been adopted to reinforce asphalt mixture in order to improve its mechanical properties. This study investigated the freeze-thaw damage characteristics of asphalt mixtures reinforced with eco-friendly basalt fiber by volume and mechanical properties—air voids, splitting tensile strength, and indirect tensile stiffness modulus tests. Test results indicated that asphalt mixtures reinforced with eco-friendly basalt fiber had better mechanical properties (i.e., splitting tensile strength and indirect tensile stiffness modulus) before and after freeze-thaw cycles. Furthermore, this study developed logistic damage models of asphalt mixtures in terms of the damage characteristics, and found that adding basalt fiber could significantly reduce the damage degree by about 25%, and slow down the damage grow rate by about 45% compared with control group without basalt fiber. Moreover, multi-variable grey models (GM) (1,N) were established for modelling the damage characteristics of asphalt mixtures under the effect of freeze-thaw cycles. GM (1,3) was proven as an effective prediction model to perform better in prediction accuracy compared to GM (1,2).

scholarly journals Effect of Hybrid Modification and Type of Compaction on the Cracking Properties of Asphalt Concrete

2020 ◽  
Vol 23 (2) ◽  
pp. 106-116
Author(s):  
Mohammed A. Abed ◽  
Alaa H. Abed
Keyword(s):  
Tensile Strength ◽  
Asphalt Mixture ◽  
Polymer Modification ◽  
Static Stiffness ◽  
Stiffness Modulus ◽  
Aggregate Gradation ◽  
Superpave Gyratory Compactor ◽  
Roller Compactor ◽  
Indirect Tensile ◽  
Styrene Butadiene

This paper focused on evaluating the effect of aggregate gradation and polymer modification on indirect tensile strength (ITS) and the static stiffness for hot asphalt mixtures. In particular, data from ITS tests have been processed to obtain stiffness measurements through the application of Hondros theory. The results showed that fine mixtures had a better tensile strength by 26.3% than the coarse mixtures. The effect of compaction also was examined, the results showed that samples compacted with the Superpave gyratory compactor (SGC) had an enhancement in ITS by 36.58 and 23.1% in comparison with Marshall and roller compactor respectively. Polymer modifiers were used to estimate their effect on tensile strength, adding 4, 6, and 8% of Styrene-Butadiene-Styrene (SBS), which can rise the ITS by 3.2,6.14 and 13.3% of the non-modified asphalt mixture. Furthermore, using 4, 6, and 8 percent of SBS could increase static stiffness by 53.9, 209.6, and 302.4% respectively for roller compacted fine mixes and 58, 220, and 379.3% for SGC compacted mixes. Furthermore, SBS raised the stiffness modulus by 52.3, 188, and 295% for Marshall compacted mixes. Using hybrid modifier can improve the stiffness of the asphalt mixture. However, The results indicate that using 1, 2 and 3% polyvinyl chloride (PVC) can magnify the stiffness of mixtures by 41.2, 199.8% and 262.6 for roller compacted mixtures and 133.4, 212.1 and 354% for SGC compacted mixtures, whereas there is a stringent increasing by 133.4, 189.2 and 354% for Marshall compacted mixes. Otherwise, polymer-modification can decrease the fracturing index for coarse and fine mixtures.

scholarly journals Rejuvenation Mechanism of Asphalt Mixtures Modified with Crumb Rubber

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood
Keyword(s):  
Tensile Strength ◽  
Dynamic Loading ◽  
Creep Compliance ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Strength Testing ◽  
Noise Mitigation ◽  
Indirect Tensile

Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.

scholarly journals Evaluation of Moisture Susceptibility for Modified Open Graded Friction Course Mixes Used Styrene Butadiene Styrene

2019 ◽  
Vol 22 (2) ◽  
pp. 94-101
Author(s):  
Miran Bahyam Ahmed ◽  
Alaa Hussein Abed ◽  
Yasir Mawla Hammood Al-Badran
Keyword(s):  
Tensile Strength ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Moisture Susceptibility ◽  
Air Voids ◽  
Indirect Tensile ◽  
Asphalt Content ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Open-graded-fraction-course (OGFC), is a hot asphalt mixture usually utilized as a private purpose wearing course, because of open graded asphalt mixture and aggregates skeleton (stone-on-stone) contact, it contain a relatively high air voids’ percentage, after compaction which are permeable to water. In this research one type of gradation was used (12.5 mm) NMAS, to preparing the OGFC asphalt mixtures, penetration grade 40/50, crushed aggregate, asphalt content prepared with 4 % and up to 6 % by weight of mixture with 0.5 % increments. Optimum asphalt content (OAC) was selected based on these criteria, air voids content, asphalt draindown, permeability, and abrasion resistance (aged and un-aged) condition. The mix performance had been investigated by indirect tensile strength and moisture susceptibility (sensitivity) measured according to the (AASHTO T283-14). Results illustrate that the increasing of asphalt binder content leads to a decrease of the air voids content, abrasion loss and permeability values, while draindown increase, conversely, the indirect tensile strength (ITS) had been significantly increased for both conditions and this is a gaod suggestion to resistance alongside moisture susceptibility. It can be decided that the increasing of asphalt  binder percent in OGFC asphalt mixture, leads to an increase in the thickness of binder coating around the aggregates. On the other hand, the influence of modifier that prepared with 4% styrene-butadiene-styrene (SBS) on OGFC asphalt mixture tends to improve the mix properties and exhibit higher (TSR) as compared with original asphalt by (31, 27.7 and 24.4) % at asphalt percent (4.8, 5.3 and 5.8) %, respectively. The SBS improved the adhesion between aggregate and asphalt which leads to reduce stripping of HMA, horizontal deformation, and increased the tensile stiffness modulus value.

scholarly journals Effect of Addition of Rubber Granulate and Type of Modified Binder on the Viscoelastic Properties of Stone Mastic Asphalt Reducing Tire/Road Noise (SMA LA)

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3446
Author(s):  
Wladyslaw Gardziejczyk ◽  
Andrzej Plewa ◽  
Raman Pakholak
Keyword(s):  
Viscoelastic Properties ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Low Noise ◽  
Asphalt Mixtures ◽  
Compression Tests ◽  
Road Noise ◽  
Stiffness Modulus ◽  
Mastic Asphalt ◽  
Stone Mastic Asphalt

The use of rubber granulate in the composition of asphalt mixtures, as well as the use of poroelastic layers, is indicated by many research centers as a factor with a positive effect on tire/road noise reduction. Attention is however paid to their lower structural durability compared to asphalt concrete (AC) or stone mastic asphalt (SMA). Stone mastic asphalt reducing tire/road noise (SMA LA) layers have also been recently used as low-noise road surfaces. The article presents the test results of viscoelastic properties of asphalt mixtures SMA8 LA, SMA8 LA containing 10%, 20%, and 30% of rubber granulate, with bitumen 50/70, bitumen 50/70 modified with styrene butadiene styrene (SBS) copolymer, crumb rubber, and mixtures with bitumen modified simultaneously with crumb rubber and SBS copolymer. The reference asphalt mixture was the porous asphalt (PA8). The presented results of water damage resistance, degradation resistance in the Cantabro abrasion loss test, stiffness modulus as a function of temperature and hysteresis loop proved that the amount of rubber granulate and the type of binder significantly affect the values of these parameters. Attention was paid to the possibility of using the results of uniaxial cyclic compression tests when determining the proportion of rubber granulate in SMA8 LA mixtures. Tests of hysteresis loops and stiffness modulus confirm much higher elasticity of SMA8 LA mixtures with rubber granulate as compared to mixtures without the addition of granulate.

Conditioning and Testing Protocol Combinations to Detect Asphalt Mixture Damage

2018 ◽  
Vol 2672 (28) ◽  
pp. 10-21 ◽  
Author(s):  
Rabeea W. Bazuhair ◽  
Carl V. Pittman ◽  
Isaac L. Howard ◽  
Walter S. Jordan ◽  
James Michael Hemsley ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Environmental Effects ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Asphalt Mixes ◽  
Freeze Thaw ◽  
Testing Protocol ◽  
Indirect Tensile

Asphalt mixes often have many ingredients that can interact with each other. When put into service, where there are multiple environmental effects, there are many interactions that need mixture testing. This paper’s objective was to evaluate laboratory conditioning protocols coupled with subsequent property measurements for their ability to detect damage of asphalt mixtures in the southeastern U.S. climate (or similar climates). The investigation’s focus is the property measurements themselves, and in particular how a given test can simultaneously assess multiple types of damage (i.e. oxidation, moisture damage, and freeze-thaw damage). While in service, mixtures can be damaged in multiple manners so laboratory conditioning protocols that expose specimens to multiple types of damage are needed as are test(s) that can detect these damages in a manner that can help assess performance during service. Four plant produced mixtures with all virgin ingredients were evaluated at intermediate temperatures with mixture and binder tests. The mixtures were well suited for such a comparison because they consisted of all virgin binder. Indirect tensile (IDT) strength did not relate to Cantabro Mass Loss (CML) or binder test results, which was concerning. Even more concerning was IDT’s inability to respond to laboratory conditioning protocols that considered multiple environmental effects (i.e., oxidation, moisture, and freeze-thaw). CML results related to binder properties and were able to reasonably detect multiple types of environmental effects. As such, Cantabro testing is recommended over tensile strength for intermediate temperature mixture property assessments related to non-load associated environmental effects.

scholarly journals Dynamic Properties and Fatigue Life of Stone Mastic Asphalt Mixtures Reinforced with Waste Tyre Rubber

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Nuha Salim Mashaan ◽  
Asim H. Ali ◽  
Suhana Koting ◽  
Mohamed Rehan Karim
Keyword(s):  
Dynamic Properties ◽  
Crumb Rubber ◽  
Fatigue Properties ◽  
Stiffness Modulus ◽  
Mastic Asphalt ◽  
Road Pavement ◽  
Stone Mastic Asphalt ◽  
Indirect Tensile ◽  
Waste Tyre ◽  
Waste Polymer

Today, virgin polymer modified asphalt mixes are comparatively more expensive for road pavement. One way to reduce the expense of such construction and to make it more convenient is the application of inexpensive polymer, such as waste polymer. The primary aim of this study was to investigate the effect of adding waste tyre rubber (crumb rubber modifier (CRM)) on the stiffness and fatigue properties of stone mastic asphalt (SMA) mixtures. Various percentages of waste CRM with size of 0.60 mm were added to SMA mixtures. Indirect tensile stiffness modulus test was conducted at temperatures of 5, 25, and 40°C. Indirect tensile fatigue test was conducted at three different stress levels (2000, 2500, and 3000 N). The results show that the stiffness modulus of reinforced SMA samples containing various contents of CRM is significantly high in comparison with that of nonreinforced samples, and the stiffness modulus of reinforced samples is in fact less severely affected by the increased temperature compared to the nonreinforced samples. Further, the results show that CRM reinforced SMA mixtures exhibit significantly higher fatigue lives compared to the nonreinforced mixtures help in and promotion of sustainable technology by recycling of waste materials in much economical and environmental-friendly manner.

scholarly journals Laboratory Evaluation of the Use of Florida Washed Shell in Open-Graded Asphalt Mixtures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe
Keyword(s):  
Tensile Strength ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Void Content ◽  
Coarse Aggregates ◽  
Significant Difference ◽  
Indirect Tensile ◽  
Marshall Stability

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.

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