Study on the Physical Properties of Recycled Cold Asphalt Using Cementless Binders

In this study, the optimal mixing conditions for recycled cold asphalt, which recycled waste asphalt and used cementless binders, was assessed through verification of the performance. The cementless binder mixing ratio of 6% desulfurization gypsum substitution rate for blast furnace slag was found to have the most outstanding properties. For the Marshall stability, 4% filler mixing brought about a 1.92 times strength increase effect compared to OPC. The flow value testing showed that an increase in the use of asphalt emulsion resulted in an increased flow value while it decreased with the increase in filler substitution rate. The optimal mixing condition that satisfied mechanical performance and durability among the test conditions assessed in this study was found to be 4% filler mixed.

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Performance Evaluation of Semiplastic Recycled Cold Asphalt Using Noncement Binders

Advances in Materials Science and Engineering ◽

10.1155/2015/239365 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Byung Jae Lee ◽

Jin Wook Bang ◽

Jeong Su Kim ◽

Young Il Jang

Keyword(s):

Mass Loss Rate ◽

Strength Increase ◽

Test Results ◽

Asphalt Emulsion ◽

Time Strength ◽

Mixing Proportion ◽

Residual Stability ◽

Marshall Stability ◽

Emulsified Asphalt ◽

Optimal Mixing

The optimal mixing conditions for semiplastic recycled cold asphalt, which recycled waste asphalt and used noncement binders (NCB), were assessed through verification of the performance. The NCB of 6% desulfurization gypsum mixing was found to have the most outstanding properties. For the Marshall stability, 4% (NCB) filler mixing brought about a 1.92-time strength increase effect compared to OPC (2%) and was improved when using modified asphalt and SBR. The flow test results showed that although an increase dosage of filler and SBR decreased the flow value of the semiplastic recycled cold asphalt, an increase dosage of asphalt emulsion improved the flow value. The indirect tensile strength and liquid immersion residual stability for the condition with greatest Marshall stability were most outstanding with 0.95 MPa and 83.6%, respectively. Evaluation of the recycled cold asphalt abrasion durability revealed that for the case of mixing more than 4% NCB the mass loss rate was lower than 20%. The abrasion durability was found to improve when using modified emulsified asphalt and SBR substitution. From the test results, it was found that the optimal mixing proportion of semiplastic recycled cold asphalt satisfied mechanical properties and durability is NCB with 4%, emulsified asphalt with 3%, and SBR substitution with 20%.

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Performance Characterization of Stone Mastic Asphalt using Steel Fiber

Journal of Advanced Industrial Technology and Application ◽

10.30880/jaita.2021.02.02.003 ◽

2021 ◽

Vol 02 (02) ◽

Author(s):

Ekarizan Shaffie ◽

◽

H.A. Rashid ◽

Fiona Shiong ◽

Ahmad Kamil Arshad ◽

...

Keyword(s):

Steel Fiber ◽

Mechanical Performance ◽

Permanent Deformation ◽

Asphalt Mixture ◽

Moisture Susceptibility ◽

Mastic Asphalt ◽

Bitumen Content ◽

Stone Mastic Asphalt ◽

The Stability ◽

Marshall Stability

Stone Mastic Asphalt (SMA) is a gap-graded hot mixture designed to provide higher resistance towards permanent deformation and rutting potential by 30% to 40% more than dense-graded asphalt, due to its stable aggregate skeleton structure. However, compared to other types of hot mix asphalt, SMA unfortunately has some shortcomings in term of its susceptibility towards moisture-induced damage due to its structure and excessive bitumen content in the composition. This research aims to assess the performance of a SMA mixture with steel fiber by enhancing overall stability, abrasion resistance, and, most importantly, moisture susceptibility. This study involved the incorporation of various steel fiber proportions of 0%, 0.3%, 0.5% and 0.7% by the total weight of mixture. The steel fiber modified SMA was made up of 6.0% PEN 60/70 bitumen content. The performance of SMA were evaluated through Marshall stability and flow test, Cantabro loss test and indirect tensile strength test. The results obtained from the testing showed that the incorporation of steel fiber is significantly effective to enhance the resistance towards moisture damage, while increasing the stability and reducing the abrasion loss of SMA mixture, compared to conventional mixture. Overall, it can be concluded that the addition of steel fiber in asphalt mixture specifically SMA, has improved the mechanical performance in the application of asphalt pavement with the optimum steel fiber proportion of 0.3% by the weight of mixture. The developed models between the independent variables and responses demonstrated high levels of correlation. The study found that Response Surface Methodology (RSM) is an effective statistical method for providing an appropriate empirical model for relating parameters and predicting the optimum performance of an asphaltic mixture to reduce flexible pavement failure.

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Effect of Water and Emulsifier on the Mechanical Properties of Cement Asphalt Mortar

MATEC Web of Conferences ◽

10.1051/matecconf/201927103002 ◽

2019 ◽

Vol 271 ◽

pp. 03002

Author(s):

Tri Ho Minh Le ◽

Dae-Wook Park ◽

Jung-Woo Seo

Keyword(s):

High Speed ◽

Mechanical Performance ◽

Strength Development ◽

Mechanical Degradation ◽

Asphalt Emulsion ◽

Term Operation ◽

Cement Asphalt Mortar ◽

Rail Structure ◽

Asphalt Mortar ◽

Mixing Water

The long-term operation of high-speed railway leads to remarkable issues in ballast mechanical degradation and track irregularity. Particularly, in mainline of rail structure, the required time for ballast layer maintenance is strictly short. To systematically cope with this problem, a comprehensive study was proposed to develop a new cement asphalt mortar (CAM) stabilized ballast method. This solution is expected to improve the ballast structural durability with fast application time. However, the engineer properties of CAM paste with different level of initial mixing water as well as the influencing mechanisms are not clearly understood. In this work, the effects of initial mixing water and emulsifier on the mechanical performance of CAM are mainly discussed. The characteristics of the mortar were determined by conducting the flowability test, mixing stability test, and unconfined compressive strength (UCS) test. The test results revealed that the initial mixing water plays an important role in both fresh and hardened stage of CAM, especially the demulsification process of asphalt emulsion. Meanwhile, the emulsifier imposed a critical effect on the strength development of CAM mixture.

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Laboratory Evaluation of Warm Stone Matrix Asphalt Mixture

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.4178 ◽

2011 ◽

Vol 243-249 ◽

pp. 4178-4181 ◽

Cited By ~ 1

Author(s):

Shao Wen Du ◽

Shan Shan Li

Keyword(s):

Low Temperature ◽

Mechanical Performance ◽

Asphalt Mixture ◽

Laboratory Evaluation ◽

Performance Properties ◽

Stone Matrix Asphalt ◽

Low Temperature Cracking ◽

Stone Mastic Asphalt ◽

Marshall Stability ◽

Warm Additives

Two kinds of warm additives, Sasobit and Evotherm DAT, were used to develop warm stone mastic asphalt (SMA) mixture. The test results showed that compaction temperature of SMA can be decreased by 30-40°C when using Sasobit or Evotherm DAT. Then, to compare the mechanical performance properties of SMA and warm SMAs, mechanical properties of pavement mixture, including Marshall stability, retained Marshall stability, tensile strength ratio, Cantabro loss, rutting dynamic stability and low temperature flexural strength, were tested in laboratory. The results indicated that Sasobit can decrease obviously the moisture resistance ability and low temperature cracking resistance ability of SMA. Therefore, the pavement performance properties of Sasobit warm SMA are inferior to those of Evotherm DAT warm SMA, which has the nearly same performance properties as hot SMA.

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Effect of Mixing Condition on the Mechanical Properties of Magnesium Based Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1087.434 ◽

2015 ◽

Vol 1087 ◽

pp. 434-438

Author(s):

Wan Nur Azrina Wan Muhammad ◽

Yoshiharu Mutoh

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Mixing Time ◽

Mixing Conditions ◽

Mixing Condition ◽

Mixing Speed ◽

Sic Particle

The effects of mixing conditions, i.e; mixing speed and mixing duration on the mechanical properties of the magnesium based composites were investigated. The hardness, tensile strength and microstructure of composites were studied. It was found that increase of the mixing speed and prolong the mixing time can improved the distribution of SiC particle and mechanical properties of magnesium based composites.

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Mechanical Performance of Asphalt Mixtures with Natural Aggregates and Recycled Aggregates for Surface Course

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.600.657 ◽

2014 ◽

Vol 600 ◽

pp. 657-666 ◽

Cited By ~ 1

Author(s):

Vagner da Costa Marques ◽

Bismak Oliveira de Queiroz ◽

Diego Meira de Lacerda ◽

Antônio Marcos de Araújo Gouveia ◽

Ricardo Almeida de Melo

Keyword(s):

Solid Waste ◽

Environmental Impacts ◽

Mechanical Performance ◽

Waste Recycling ◽

Asphalt Mixtures ◽

Recycled Concrete ◽

Recycled Aggregates ◽

Asphalt Mix ◽

Natural Aggregates ◽

Marshall Stability

The recycled aggregates of construction and demolition solid waste can be used on pavements to decrease environmental impacts in cities. Thus, this study aimed to compare the mechanical performance of asphaltic mixtures made with natural aggregates and concrete recycled aggregates for surface course of pavements. The materials were collected in an asphalt mixing plant and in a construction and demolition solid waste recycling plant located in João Pessoa/PB, Brazil. The Marshall asphalt mix design was chosen to determine optimum asphalt content and evaluate mechanical performance of asphaltic mixtures. The asphalt mixtures specimens were composed of natural aggregates, and afterwards of recycled aggregates with percent contents of 25, 50 and 100. The optimum asphalt contents were 5.7 and 7.5%, Marshall stability of 1,070 and 790 Kgf, flow of 6.2 and 5.7 mm for natural aggregate asphalt mixtures and asphalt mixtures with 25% recycled aggregates, respectively. Moreover, percent air voids and percent voids filled with asphalt met the Brazilian DNIT: ES 031/2006 specified standard. However, the asphalt mixtures with 50 and 100% recycled aggregates did not meet the specified standard. Therefore, it was concluded that the replacement of natural aggregates with 25% recycled concrete aggregates in asphalt mixtures can be technically viable to build asphalt surface course on pavements, besides lowering pavement costs and decreasing environmental impacts.

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Reclaimed Polymers as Asphalt Binder Modifiers for More Sustainable Roads: A Review

Sustainability ◽

10.3390/su11030646 ◽

2019 ◽

Vol 11 (3) ◽

pp. 646 ◽

Cited By ~ 26

Author(s):

Luzana Brasileiro ◽

Fernando Moreno-Navarro ◽

Raúl Tauste-Martínez ◽

Jose Matos ◽

Maria Rubio-Gámez

Keyword(s):

Mechanical Performance ◽

Asphalt Binder ◽

Crumb Rubber ◽

Economic Benefits ◽

Asphalt Binders ◽

Mixing Conditions ◽

Ethyl Vinyl ◽

General Terms ◽

Comparative Review ◽

Modified Binder

The use of polymer-modified binders in asphalt mixtures has become more widespread due to their reduced thermal susceptibility and improved rutting and fatigue resistance. Nevertheless, their high cost limits their application, thus making the use of reclaimed polymers (RP) an interesting alternative for both reducing price and extending the service life of pavements. This paper; therefore, presents a comparative review of the recycled polymers most commonly studied as bitumen modifiers: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), ethyl vinyl acetate (EVA), and ground tire rubber (GTR), in order to facilitate their selection and extend the use of the bitumen. The differences in terms of melting point, mixing conditions, and maximum quantity of added polymer are analyzed. Moreover, their effect on the mechanical behavior of the asphalt binders and their stability with and without the use of additives is presented. According to the literature revision, the performance of the new binder is more influenced by the kind of polymer that was incorporated and the mixing conditions than by the base bitumen that was chosen, although rheological evaluation is needed to fully understand the modification mechanisms of the modified binder. In general terms, plastomers have a stronger effect in terms of increasing the stiffness of the bitumen in comparison with crumb rubber (elastomers), thus providing an improved rutting resistance. The joint use of polyethylene (plastomer) and crumb rubber (elastomer) can be an interesting option for its recycling potential and mechanical performance, although further study is needed to achieve stable bitumen across the entire range of temperatures; additives, such as maleic anhydride (MA), are commonly employed to improve the stability of the binder and enhance its characteristics, but their use could limit the economic benefits of using recycled materials.

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Strength Characteristics of Controlled Low-Strength Materials with Waste Paper Sludge Ash (WPSA) for Prevention of Sewage Pipe Damage

Materials ◽

10.3390/ma13194238 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4238

Author(s):

Jeongjun Park ◽

Gigwon Hong

Keyword(s):

Bearing Capacity ◽

Cement Content ◽

Paper Sludge ◽

Mixing Conditions ◽

Sewage Pipe ◽

Weathered Soil ◽

Allowable Bearing Capacity ◽

Paper Sludge Ash ◽

Sludge Ash ◽

Optimal Mixing

In this study, the effects of the mixing conditions of waste paper sludge ash (WPSA) on the strength and bearing capacity of controlled low-strength material (CLSM) were evaluated, and the optimal mixing conditions were used to evaluate the strength characteristics of CLSM with recyclable WPSA. The strength and bearing capacity of CLSM with WPSA were evaluated using unconfined compressive strength tests and plate bearing tests, respectively. The unconfined compressive strength test results show that the optimal mixing conditions for securing 0.8–1.2 MPa of target strength under 5% of cement content conditions can be obtained when both WPSA and fly ash are used. This is because WPSA and fly ash, which act as binders, have a significant impact on overall strength when the cement content is low. The bearing capacity of weathered soil increased from 550 to 575 kPa over time, and CLSM with WPSA increased significantly, from 560 to 730 kPa. This means that the bearing capacity of CLSM with WPSA was 2.0% higher than that of weathered soil immediately after construction; furthermore, it was 27% higher at 60 days of age. In addition, the allowable bearing capacity of CLSM corresponding to the optimal mixing conditions was evaluated, and it was found that this value increased by 30.4% until 60 days of age. This increase rate was 6.7 times larger than that of weathered soil (4.5%). Therefore, based on the allowable bearing capacity calculation results, CLSM with WPSA was applied as a sewage pipe backfill material. It was found that CLSM with WPSA performed better as backfill and was more stable than soil immediately after construction. The results of this study confirm that CLSM with WPSA can be utilized as sewage pipe backfill material.

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The Influence of Mixing Conditions on the Macro-Scale Homogeneity of Asphalt Mixtures Blended with Reclaimed Asphalt Pavement (RAP)

Materials ◽

10.3390/ma14154137 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4137

Author(s):

Quan Liu ◽

Markus Oeser

Keyword(s):

Mechanical Performance ◽

Design Method ◽

Asphalt Pavement ◽

Mixing Time ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Mixing Conditions ◽

Recycled Asphalt ◽

Reclaimed Asphalt ◽

Macro Scale

The homogeneity of asphalt mixtures blended with reclaimed asphalt pavement (RAP) is affected by many factors. Due to the complicated compositions of recycled asphalt mixtures, the inhomogeneity issue might cause insufficient mechanical properties of asphalt mixtures, even though a design method was appropriately adopted. Therefore, it is of great significance to study the influence of mixing conditions on the homogeneity of asphalt mixtures blended with RAP materials. This study focused on the macro-scale homogeneity of produced asphalt mixtures. Specifically, asphalt mixtures incorporated with 40% RAP content were produced in a laboratory using different mixing times and mixing temperatures. A multi-direction indirect tensile stiffness modulus (ITSM) test was proposed to quantify the homogeneity of produced samples. In addition, the digital image processing (DIP) method was used to identify the distribution of aggregates and RAP binder. The results indicated that the influence of mixing time on the macro-homogeneity of asphalt mixtures indicated that a longer mixing time was favorable for the material dispersion. The influence of mixing temperature mainly rested on two perspectives. One was that the temperature variation induced the change of binder viscosity. The other was that the temperature influences the diffusion process between RAP binder and new bitumen, which further affected the mechanical performance of produced asphalt mixtures.

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The Influence of Nanoclay on the Flame Retardancy and Mechanical Performance of Recycled Carpet Composites

Recycling ◽

10.3390/recycling4020022 ◽

2019 ◽

Vol 4 (2) ◽

pp. 22

Author(s):

Kunal Mishra ◽

Ranji Vaidyanathan

Keyword(s):

Flame Retardancy ◽

Moisture Absorption ◽

Mechanical Performance ◽

Ignition Time ◽

Polymer Network ◽

Degradation Process ◽

Condensation Condition ◽

Recycled Waste ◽

Composite Samples ◽

Vartm Process

In the present study, we recycled waste carpet using a vacuum-assisted resin transfer molding (VARTM) process. Three different variations of carpet composites were fabricated, namely, neat epoxy, clay-coated, and clay-infused carpet composites. The carpet composite samples were degraded hygrothermally as well as under a cyclic UV condensation condition. Presence of clay was shown to impede the moisture absorption and UV degradation in the carpet composites. Flexural properties also showed that the presence of clay slows the degradation process of the composites. The flame retardancy result indicated that the presence of clay in the polymer network decreases the ignition time of the carpet composites.

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