scholarly journals Study of the Stiffness of the Bitumen Emulsion Based Cold Recycling Mixes for Road Base Courses

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5473
Author(s):  
Katarzyna Konieczna ◽  
Piotr Pokorski ◽  
Wojciech Sorociak ◽  
Piotr Radziszewski ◽  
Dawid Żymełka ◽  
...  
Keyword(s):  
Road Construction ◽  
Reclaimed Asphalt Pavement ◽  
Stiffness Modulus ◽  
Pavement Rehabilitation ◽  
Reclaimed Asphalt ◽  
Bitumen Emulsion ◽  
Potential Benefits ◽  
Indirect Tensile ◽  
Reduction Of Energy Consumption ◽  
Cold Recycling

The benefits of the use of cold recycling mixtures (CRMs) in pavement rehabilitation are associated with both the reduction of natural resource consumption by replacing them with recycled materials and the reduction of energy consumption during their production and paving. The evolution of the stiffness of CRMs in road construction and the fatigue life of pavements with CRM base layers are still being investigated. In this paper, CRMs with 1% cement content, called bitumen-stabilized materials with bitumen emulsion (BSM-Es), were examined. Mixtures that were differentiated in terms of Reclaimed Asphalt Pavement (RAP) content, as well as the amount and type of bitumen emulsions, were subjected to indirect tensile stiffness modulus (ITSM) tests at 5 °C, 13 °C, and 20 °C. The thermal sensitivities of the BSM-E mixtures were analyzed. BSM-E mixture stiffness modulus levels at various temperatures were determined using a statistical approach. On the basis of the results obtained, a discussion on the mechanistic-empirical design of flexible pavements with BSM-E base layers is presented. The potential benefits of using BSM-E materials in road construction in certain aspects of pavement life are indicated.

Review of Lithuanian Experience in Asphalt Pavements Cold Recycling

2017 ◽  
Author(s):  
Audrius Vaitkus ◽  
Judita Gražulytė ◽  
Lina Juknevičiūtė-Žilinskienė ◽  
Vitalijus Andrejevas
Keyword(s):  
Asphalt Pavement ◽  
Road Construction ◽  
White Paper ◽  
Asphalt Pavements ◽  
Pavement Rehabilitation ◽  
Reclaimed Asphalt ◽  
Bitumen Emulsion ◽  
Base Course ◽  
Foamed Bitumen ◽  
Cold Recycling

One of the key goals in the EU White Paper is to reduce carbon emissions in transport by 60% by 2050. Consequently, during the past years an effect on the environment became a decisive factor in selecting materials and technologies for road construction and rehabilitation. Cold recycling is a reasonable solution in asphalt pavement rehabilitation because it is economical and old asphalt pavements can be reused. This technology differs from others by mixing temperature. Besides, cold recycling does not require additional heating. These benefits result in wide application of cold recycling around the world. In Lithuania, cold recycling has been used for more than 15 years. Both technologies, i.e. cold in-plant recycling and cold in-place recycling, were used. In both technologies reclaimed asphalt pavement (RAP) is bound with bituminous binders (foamed bitumen or bitumen emulsion), hydraulic binders (cement) or a combination of bituminous and hydraulic binders depending on the base course specifications. This paper focuses on the Lithuanian experience in cold recycling of asphalt pavements using different types of cold recycling and binders.

scholarly journals Effect of Rejuvenating Agent on the Pavement Properties of Cold Recycled Mixture with Bitmen Emulsion

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 520
Author(s):  
Chun Li ◽  
Jian Ouyang ◽  
Peng Cao ◽  
Jingtao Shi ◽  
Wenting Yang ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Membrane Structure ◽  
Asphalt Pavement ◽  
Good Choice ◽  
Reclaimed Asphalt Pavement ◽  
Moisture Susceptibility ◽  
Reclaimed Asphalt ◽  
Bitumen Emulsion ◽  
Indirect Tensile ◽  
Application Scope

A traditional cold recycled mixture with bitumen emulsion (CRMB) has a relatively low cracking resistance and moisture susceptibility, which greatly limits its application scope. A rejuvenating agent was employed to improve the pavement properties of CRMB. To avoid the rejuvenating agent having an adverse effect on the new bitumen, reclaimed asphalt pavement (RAP) was firstly treated by the rejuvenating agent, and the effect of rejuvenating time on the pavement properties of CRMB was investigated. Results indicate that the addition of a rejuvenating agent can greatly improve the ductility and moisture susceptibility of CRMB. Meanwhile, although the rejuvenating agent can soften aged bitumen, the addition of a rejuvenating agent can still increase the indirect tensile strength of CRMB and does not greatly reduce the rutting resistance of CRMB. This phenomenon exists because the rejuvenating agent can be both beneficial to the membrane structure of the bitumen emulsion mastic and aged bitumen. It can also greatly improve the bonding interface between RAP and the bitumen emulsion mastic. The rejuvenating time between RAP and the rejuvenating agent can affect the pavement properties of CRMB. To obtain better pavement properties, the optimum recommended rejuvenating time is between 5 and 7 days. Overall, the addition of rejuvenating agent can be a good choice to improve the pavement properties of CRMB.

Effect of Mixing Time and Temperature on the Homogeneity of Asphalt Mixtures Containing Reclaimed Asphalt Pavement Material

2018 ◽  
Vol 2672 (28) ◽  
pp. 167-177 ◽  
Author(s):  
Jiantao Wu ◽  
Quan Liu ◽  
Yu Wang ◽  
Jun Chen ◽  
Dawei Wang ◽  
...  
Keyword(s):  
Color Image ◽  
Asphalt Pavement ◽  
Mixing Time ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Mixing Conditions ◽  
Stiffness Modulus ◽  
Reclaimed Asphalt ◽  
Average Value ◽  
Indirect Tensile

Laboratory-produced reclaimed asphalt pavement (RAP) material, new aggregate, and tinted new binder were mixed (RAP proportion: 40%) with 12 different combinations of mixing temperatures and times, based on which circular specimens of various thicknesses were fabricated and then subjected to multi-direction indirect tensile stiffness modulus (ITSM) testing and color image analysis. Statistical calculations including average value, coefficient of variation, standard deviation, and range were carried out to investigate the effects of different mixing conditions on the homogeneity of asphalt mixtures containing RAP. The results show that the deterioration of homogeneity of asphalt mixtures containing RAP was mainly caused by the asynchronous breaking of clusters. The mixing temperature was decisive in determining the resistance of clusters to breaking, and for mixing conditions chosen in this study, the resistance increases with the increase of mixing temperature. Short mixing time might lead to a phenomenon of “momentary homogeneity,” in which clusters were not broken and the blending degree between aged and new binder was low.

scholarly journals Development of Cold In-Place Recycling with Bitumen Emulsion and Biomass Bottom Ash

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Jorge Suárez-Macías ◽  
Juan María Terrones-Saeta ◽  
Francisco Javier Iglesias-Godino ◽  
Francisco Antonio Corpas-Iglesias
Keyword(s):  
Raw Materials ◽  
Asphalt Pavement ◽  
Bottom Ash ◽  
Road Construction ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Bituminous Mixtures ◽  
Limestone Aggregate ◽  
Bitumen Emulsion ◽  
Biomass Fly Ash

Power generation from biomass is one of the most promising energy sources available today. However, this industry has a series of wastes derived from its activity, mainly biomass fly ash and biomass bottom ash. Biomass bottom ash is a waste that has no current use and, in most cases, is deposited in landfills. In turn, road construction is one of the activities that produces the most pollution, as it requires huge amounts of raw materials. Therefore, this research proposes the use of biomass bottom ashes, in an unaltered form, for the formation of cold in-place recycling with bitumen emulsion. This type of mixture, which is highly sustainable owing to the use of a high percentage of waste, was made with reclaimed asphalt pavement, biomass bottom ash, water, and bitumen emulsion. To this end, the grading curve of the materials was analyzed, different bituminous mixtures were made with varying percentages of emulsion and water, and the mechanical properties of the mixtures were analyzed. At the same time, the same type of mix was made with reclaimed asphalt pavement and commercial limestone aggregate, in order to compare the results. The tests showed a better mechanical behavior of the bituminous mixes made with biomass bottom ash, maintaining physical properties similar to those of conventional mixes. In short, it was confirmed that the production of this type of mix with biomass bottom ash was feasible, creating sustainable materials that reuse currently unused waste and avoid landfill disposal.

scholarly journals Application of the foamed bitumen and bitumen emulsion to the road base mixes in the deep cold recycling technology

2016 ◽  
Vol 11 (4) ◽  
pp. 291-301 ◽  
Author(s):  
Marek Iwański ◽  
Anna Chomicz-Kowalska
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Base Layer ◽  
The Road ◽  
Road Base ◽  
Bitumen Emulsion ◽  
Recycling Technology ◽  
Indirect Tensile ◽  
Foamed Bitumen ◽  
Cold Recycling

This paper presents findings of a study concerning the influence of binder type on the mechanical properties of road base in the cold recycling technology. The principal aim of this investigation was to evaluate the mixes in scope of susceptibility to moisture and low-temperatures. In the comparative research foamed bitumen and bitumen emulsion were used in four different concentrations (2.0%, 2.5%, 3.0%, 3.5%). The materials used in the study were reclaimed from an existing road construction layers: reclaimed aggregate from the road base and reclaimed asphalt pavement obtained by milling the surface and binder course. Portland cement in 2.0% concentration was used as a hydraulic binder. The evaluated parameters were: indirect tensile strengths, tensile strength retained and indirect tensile stiffness modulus at 25 °C. These tests were complemented by an evaluation of susceptibility to moisture and frost according to modified procedures implemented by American researchers: Tunnicliff, Root and Lottman. Moreover, tests for low-temperature cracking were conducted according to Finnish standard. The investigations showed that the use of foamed bitumen for road base layer produced in the cold recycling technology results in better mechanical properties and resistance to moisture and frost compared to using bitumen emulsion. The use of 2.5% of foamed bitumen and 2.0% of Portland cement in the recycled road base allowed to meet the established criteria.

scholarly journals Laboratory characterization of reclaimed asphalt pavement for road construction in Egypt

2017 ◽  
Vol 44 (6) ◽  
pp. 417-425 ◽  
Author(s):  
E. Mousa ◽  
A. Azam ◽  
M. El-Shabrawy ◽  
S.M. El-Badawy
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Road Construction ◽  
California Bearing Ratio ◽  
Base Layer ◽  
Coefficient Of Determination ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Load Duration ◽  
The Impact

This paper presents the engineering characteristics of reclaimed asphalt pavement (RAP), blended with virgin aggregate for unbound base and subbase layers. The proportions of RAP were 0%, 20%, 60%, 80%, and 100% by total mass of the blend. The experimental laboratory testing included index properties such as gradation, modified Proctor compaction, California Bearing Ratio, and hydraulic conductivity. Repeated load resilient modulus testing was conducted on the blends. The impact of load duration on resilient modulus was also investigated. A strong inverse trend was found between resilient modulus and California Bearing Ratio. An accurate model was proposed for the prediction of the resilient modulus as a function of stress state and reclaimed asphalt pavement percentage with coefficient of determination of 0.94. Finally, multilayer elastic analysis of typical pavement sections with the base layer constructed of virgin aggregate and reclaimed asphalt pavement blends showed good performance.

scholarly journals Mechanical performance assessment of half warm recycled asphalt mixes containing up to 100 % RAP

2017 ◽  
Vol 7 (080) ◽  
pp. 129 ◽  
Author(s):  
J. M. Lizárraga ◽  
A. Jiménez del Barco-Carrión ◽  
A. Ramírez ◽  
P. Díaz ◽  
F. Moreno-Navarro ◽  
...  
Keyword(s):  
Hot Mix Asphalt ◽  
Mechanical Performance ◽  
Asphalt Pavement ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Asphalt ◽  
Stiffness Modulus ◽  
Asphalt Mixes ◽  
Reclaimed Asphalt ◽  
Second Stage ◽  
Asphalt Content

The use of Half Warm Mixes with high Reclaimed Asphalt content (HWMRA) has the potential to generate significant environmental advantages such as the reduction in consumption of natural resources and the emission of gases into the atmosphere. This paper therefore focuses on demonstrating the viability of using these types of mixes in wearing courses. For this purpose, an HWMRA with 70 % and 100 % Reclaimed Asphalt Pavement (RAP) and emulsion were designed in the laboratory. The performance of the mixes was then assessed and compared with that of conventional Hot Mix Asphalt. In a second stage, the mixes were manufactured in-plant, and laid and compacted in an Accelerated Pavement Test track. The cores were then extracted and tested for stiffness modulus and resistance to fatigue. The results from the tests conducted with both the laboratory specimens and the cores showed that the performance of HWMRA is comparable to that of HMA. These findings encourage greater confidence in promoting the use of these types of sustainable asphalt mixes.

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