scholarly journals Multi-Scale Rheo-Mechanical Study of SMA Mixtures Containing Fine Crumb Rubber in a New Dry-Hybrid Technology

2020 ◽  
Vol 10 (11) ◽  
pp. 3887
Author(s):  
Francesco Mazzotta ◽  
Piergiorgio Tataranni ◽  
Andrea Simone ◽  
Daniele Fornai ◽  
Gordon Airey ◽  
...  
Keyword(s):  
Complex Modulus ◽  
Crumb Rubber ◽  
Direct Tension ◽  
Stiffness Modulus ◽  
Hybrid Technology ◽  
Multi Scale ◽  
Mechanical Study ◽  
Stone Mastic Asphalt ◽  
Points Of View ◽  
Technology Effects

Aiming to study the rheo-mechanical effects of fine crumb rubber into gap graded stone mastic asphalt (SMA) mixtures, a multi-scale experimental approach was adopted. Therefore, in the perspective of the reuse of end of life tires’ in asphalt layers, the adopted new dry-hybrid technology effects have been investigated from the mastic, mortar and mixture points of view. The new rubberized asphalt production technology allows the use of rubber powder as filler, the rubber amount optimization being validated through multi-scale performance tests. Mastics and mortars’ complex modulus measured with dynamic shear and torsional tests were related to the mixture stiffness modulus recorded in direct tension-compression mode. The rheological properties of mastic are strictly influenced by the rubber presence, and consequently the asphalt mixtures stiffness and thermo-sensitivity are connected to the mastic and mortar rheo-mechanical behavior. Results are consistent through the adopted approach and reveal that with the new dry-hybrid technology, overcoming the wet and dry limits, it seems to be possible obtaining more durable and eco-friendly bituminous pavement layers.

The Influence of Hydrated Lime, Portland Cement and Cement Dust on Rheological Properties of Recycled Cold Mixes with Foamed Bitumen

2017 ◽  
Author(s):  
Przemysław Buczynski ◽  
Marek Iwanski
Keyword(s):  
Portland Cement ◽  
Rheological Properties ◽  
Complex Modulus ◽  
Hydrated Lime ◽  
Laboratory Evaluation ◽  
Cement Kiln ◽  
Direct Tension ◽  
Stiffness Modulus ◽  
Hydraulic Binder ◽  
Foamed Bitumen

This article presents a laboratory evaluation of the viscoelastic properties of recycled base courses produced with different fillers. The aim of this study was to investigate the influence of loading time and temperature on the complex modulus (E*) and the phase angle (6) of recycled base courses with respect to selected additives used. The mixtures contained reclaimed asphalt pavement RAP, crushed stone from existing base courses and virgin aggregate. Foamed bitumen 50/70 at 2.5% was used as a binder. The hydraulic binder constituted 3.0% of the recycled base course mixture. Portland cement, hydrated lime and cement kiln dust CKD were added as fillers. Evaluation of rheological properties of recycled base courses according to selected additives was carried out to the procedure set out in EN 12697-26 annex D. The evaluation of stiffness modulus was conducted in the direct tension- compression test on cylindrical samples (DTC-CY). The samples were subjected to the cycles of sinusoidal strain with an amplitude Bo < 25μB. All tests were performed over a range of temperatures (5 ºC, 13 ºC, 25 ºC, 40 ºC) and loading times (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz). The results were used to model stiffness modulus master curves of the recycled base courses containing selected additives in the hydraulic binder.

Stone mastic asphalt (SMA) with crumb rubber according to a new dry-hybrid technology: A laboratory and trial field evaluation

2018 ◽  
Vol 182 ◽  
pp. 200-209 ◽  
Author(s):  
Cesare Sangiorgi ◽  
Piergiorgio Tataranni ◽  
Andrea Simone ◽  
Valeria Vignali ◽  
Claudio Lantieri ◽  
...  
Keyword(s):  
Field Evaluation ◽  
Crumb Rubber ◽  
Hybrid Technology ◽  
Mastic Asphalt ◽  
Trial Field ◽  
Stone Mastic Asphalt

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.

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 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 THE IMPACT OF AGEING ON THE BITUMEN STIFFNESS MODULUS USING THE CAM MODEL

2018 ◽  
Vol 13 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Małgorzata CHOLEWIŃSKA ◽  
Marek IWAŃSKI ◽  
Grzegorz MAZUREK
Keyword(s):  
Complex Modulus ◽  
Surface Active Agent ◽  
Active Agent ◽  
Age Hardening ◽  
Fatty Amine ◽  
Modified Bitumen ◽  
Stiffness Modulus ◽  
The Impact ◽  
Cam Model

This article presents the results of the viscoelastic properties of the polymer-modified bitumen produced in Warm Mix Asphalt technology. A Fischer-Tropsch synthetic wax and a liquid surface-active agent (fatty amine) were used as bitumen viscosity-reducing modifiers. All tested parameters were determined after short-term and long-term ageing. The complex modulus G* and phase angle δ were measured with a cone-plate rheometer. All dynamic tests were performed at 60 °C within the frequency range from 0.005 Hz to 10 Hz. On the basis of the rheological index R determined using the Christensen−Anderson−Marasteanu (CAM) model, it was found that the fatty amine additive slowed down the age-hardening process in the bitumen. In contrast, the synthetic wax increased the stiffness of the bitumen at all levels tested, regardless of the type of ageing simulation process.

The Viscoelastic Characteristics of the Asphalt Concrete Modified with Different Synthetic Waxes Using a Modified Huet- Sayegh Model

2017 ◽  
Author(s):  
Grzegorz Mazurek
Keyword(s):  
Asphalt Concrete ◽  
Dynamic Modulus ◽  
Complex Modulus ◽  
Model Parameters ◽  
Fischer Tropsch ◽  
Stiffness Modulus ◽  
Molecular Weights ◽  
Cole Diagram ◽  
Sinusoidal Load ◽  
Viscoelastic Characteristics

The article presents the results of dynamic modulus tests carried on the asphalt concrete (AC16W). The sinusoidal load was applied to the samples in accordance with DTC-CY method. The neat bituminous binder (penetration grade 35/50) was modified by means two synthetic waxes, coming from the Fischer-Tropsch raction, with various molecular weights and softening point temperature results (hard and softer). The relaxation phenomenon in terms of changes in complex modulus and phase angle was evaluated using the modified Huet-Sayegh (2S2P1D). Estimated model parameters pointed out that the addition of the synthetic wax with the high (hard wax) and the low (softer wax) molecular weight raised the stiffness of the bituminous binder in relation to the reference bitumen 35/50. The application of the modified Huet-Sayegh model showed that the presence of the synthetic wax in the bitumen significantly affected the stiffness modulus of considered asphalt concretes. Basing analysis on Cole-Cole diagram it was found significant differences in the viscoelastic behaviour between the reference asphalt concrete and the asphalt concretes with synthetic waxes. In contrast, there were no significant differences between viscoelastic properties of tested asphalt concretes modified, used in the experiment, synthetic waxes. Furthermore, the sensitivity to the loading time of asphalt concretes containing both synthetic waxes was marginal.

scholarly journals Laboratory Evaluation of Asphalt Binder Modified with Crumb Rubber and Basalt Fiber

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Li Liu ◽  
You Huang ◽  
Zhaohui Liu
Keyword(s):  
Shear Strength ◽  
Low Temperature ◽  
Complex Modulus ◽  
Heavy Traffic ◽  
Asphalt Binder ◽  
Basalt Fiber ◽  
Crumb Rubber ◽  
Traffic Load ◽  
Laboratory Evaluation ◽  
Temperature Property

Asphalt pavement subjected to heavy traffic load and harsh environmental conditions can easily build up damage and shorten the service life. In this paper, different dosages of basalt fiber (BF) were introduced into crumb rubber (CR) modified asphalt binder, and a series of laboratory tests were carried out to evaluate the properties and performances. A dynamic shear rheometer (DSR) was employed to evaluate viscosity and rheological properties. Bending beam rheometer (BBR) test and direct tensile test (DTT) were conducted to test the low temperature property. Cone penetration was designed to test shear strength. Results show that the optimum content of BF is 0.3% by the weight of asphalt binder based on the overall performance evaluation. Viscosity, complex modulus, fatigue property, rutting resistance, and shear strength are improved by introducing BF into asphalt binder. Stiffness and elasticity are also increased. BBR indicates that ductility at low temperature is reduced a little by the presence of BF, but DTT shows that both tensile strength and elongation are improved by BF. Considering that DTT is more performance related, DTT is preferred over BBR to evaluate cracking potentials at low temperatures of asphalt binder modified with CR and BF. Finally, it is revealed through microscale scanning that three mechanisms, absorption of asphalt binder, 3-dimensional fiber network, and bridging effects, contribute to the performance improvement of asphalt binder modified with CR and BF.

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