scholarly journals Fatigue Life Comparison of Recycled Cold Mixes with Foamed Bitumen and with Bitumen Emulsion

2017 ◽  
Vol 172 ◽  
pp. 135-142 ◽  
Author(s):  
Przemysław Buczyński ◽  
Marek Iwański
Keyword(s):  
Fatigue Life ◽  
Bitumen Emulsion ◽  
Foamed Bitumen ◽  
Cold Mixes

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 Delivering Sustainable Solutions through Improved Mix and Structural Design Functions for Bitumen Stabilised Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
K. J. Jenkins ◽  
C. E. Rudman ◽  
C. R. Bierman
Keyword(s):  
Structural Design ◽  
Best Practice ◽  
Design Method ◽  
Design Procedure ◽  
Design Methods ◽  
Mix Design ◽  
Sustainable Solutions ◽  
Bitumen Emulsion ◽  
Design Function ◽  
Foamed Bitumen

The evolution of cold recycling using bitumen stabilisation technology has been supported by progressive research initiatives and best practice guidelines. The first generic guidelines for bitumen stabilised materials (BSMs) were published only in 2002. These guidelines provided a generic approach for the analysis of foamed bitumen and bitumen emulsion technologies. From that point, bitumen stabilisation became the common term for the inclusion of either of the two bituminous binders. The TG2 2nd edition guideline of 2009 took a bold step recognising the shear properties of the bitumen stabilised material (BSM) as the key performance indicators. In addition, advancements in structural design and application of BSMs provided practitioners with robust guidelines. The subsequent decade has provided an opportunity to interrogate data from more than 300 BSM mix designs and 69 LTPP sections. The data have led to research developments including significant new performance properties of BSMs, refined mix design methods, and updated new pavement design methods. This includes an entire design process that has been updated with a streamlined mix design procedure and a new frontier curve for the pavement number design method, as well as a new mechanistic design function. It is anticipated that the research findings and implementation of the newly developed technology will lead to improved application in BSM technology.

scholarly journals LABORATORY FATIGUE MODELS FOR RECYCLED MIXES WITH POZZOLANIC CEMENT AND BITUMEN EMULSION / PUCOLANINIO CEMENTO IR BITUMINIŲ EMULSIJŲ MIŠINIŲ PERDIRBIMO LABORATORINIAI NUOVARGIO MODELIAI

2011 ◽  
Vol 17 (1) ◽  
pp. 98-107 ◽  
Author(s):  
Amir Kavussi ◽  
Fereidoon Moghadas Nejad ◽  
Amir Modarres
Keyword(s):  
Fatigue Life ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Resilient Modulus ◽  
Fatigue Behavior ◽  
Fatigue Cracking ◽  
Strain Level ◽  
Initial Stiffness ◽  
Bitumen Emulsion ◽  
Pozzolanic Cement

In recent years, due to technical and economical advantages, the production of pozzolanic cements have considerably extended. In the case of asphalt recycling, using Pozzolonic cements has several advantages. Lower initial stiffness and less shrinkage microcracks than Ordinary Portland Cement (OPC) are some benefits of pozzolanic cements which may reduce the probability of occuring premature cracking in recycled layer. In this reserach in order to investigate the effects of I (PM) pozzolanic cement on the fatigue cracking of recycled mixes with bitumen emulsion and develope fatigue models for these mixes, extensive indirect tensile fatigue and resilient modulus tests were performed at different temperatures and curing times. Test results showed that at high strain levels I (PM) cement specimens have superior fatigue behavior than OPC specimens. Furthermore, the effects of I (PM) cement on fatigue life of recycled mixes related to the initial strain level. Therefore a boundary strain level was determined. Above the boundary strain level, adding cement caused a reduction in fatigue life, whereas below that level the reverse was true. Finally based on laboratory testing results distinct models were established for different boundary strain levels. Santrauka Pastaraisiais metais dėl techninių ir ekonominių veiksnių pucolaninio cemento gamyba gerokai padidėjo. Pucolaninio cemento naudojimas perdirbant asfaltą turi keletą pranašumų. Mažesnis pradinis standumas ir mažiau mikroįtrūkių nei įprastame portlandcementyje (Ordinary Portland Cement, OPC) – tai keletas pucolaninio cemento pranašumų, galinčių sumažinti priešlaikinio plyšių atsiradimo tikimybę perdirbamame sluoksnyje. Šiuo moksliniu tyrimu siekiama ištirti I (PM) pucolaninio cemento poveikį nuovargio plyšių atsiradimui perdirbamuose bituminių emulsijų mišiniuose ir sukurti šių mišinių nuovargio modelius. Buvo atlikti išplėstiniai netiesioginio tempimo nuovargio ir elastingumo modulių bandymai, esant skirtingoms temperatūroms ir džiūvimo laikui. Bandymų rezultatai parodė, kad esant aukštam įtempimo lygiui I(PM) cemento bandiniai yra atsparesni nuovargiui nei portlandcemenčio (Ordinary Portland Cement, OPC) bandiniai. Be to, perdirbtų mišinių iš I (PM) cemento tvarumas yra artimas pirminiam įtempimo lygiui. Todėl buvo nustatytas ribinis įtempimo lygis. Viršijus ribinį įtempimo lygį ir įmaišius cemento tvarumas sumažėja, o esant žemesniam įtempimo lygiui buvo gautas priešingas rezultatas. Galiausiai remiantis tyrimais buvo nustatyti atskiri modeliai skirtingiems ribiniams įtempimo lygiams.

Evaluation of Factors Influencing strength of Foamed Bitumen Stabilised Mix

2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Mohd Rosli Hainin ◽  
Mohd Yazip Matori ◽  
Oluwasola Ebenezer Akin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Resilient Modulus ◽  
Indirect Tensile Strength ◽  
Asphalt Pavements ◽  
Curing Time ◽  
Bitumen Emulsion ◽  
Indirect Tensile ◽  
Foamed Bitumen

Over recycling of asphalt pavements involves mixing of existing pavement material with stabilizing agent such as foamed bitumen, bitumen emulsion, cement or lime and placed on the milled pavement and compacted. The strength of foamed bitumen stabilized mix is influenced by factors such as cement content, moisture level and curing time. It was found that the strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) values, increased with curing time and percentage of active filler. It was also found that the maximum strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) was not at Optimum Moisture Content (OMC) and the strength decreased as the RAP proportion increased

scholarly journals The influence of laboratory compaction methods on the physical and mechanical properties of foamed bitumen recycled mixes

2014 ◽  
Vol 13 (1) ◽  
pp. 053-062
Author(s):  
Marek Iwański ◽  
Anna Chomicz-Kowalska ◽  
Piotr Ramiączek ◽  
Krzysztof Maciejewski ◽  
Mateusz Iwański
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Moisture Damage ◽  
Hydraulic Press ◽  
Compaction Process ◽  
Road Base ◽  
Bitumen Emulsion ◽  
Foamed Bitumen ◽  
The Impact ◽  
Compaction Method

This study attempts to evaluate the influence of two advisable methods for compacting laboratory specimens of road base recycled mixes with foamed bitumen (MCAS) and bitumen emulsion (MCE). The obligatory regulations for this technology permit fabrication of the specimens using either an impact Marshall compactor or a static hydraulic press. The research showed that the compaction method influenced both the physical and mechanical properties of samples regardless of the type of bitumen binder. What is more, the structure of the material changed after the impact compaction process, which manifested in fact that many of the aggregate particles were crushed in its course. Better strength and resistance to moisture damage was observed in samples prepared in the hydraulic press. This was associated with lower void contents obtained in this compaction method.

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.

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