Bituminous mixtures with low percentage of natural aggregates and rubber modified bitumen with wax

Chile is the first Latin American country to begin an “ecological overdraft”, as established by the Global Footprint Network (GFN). This implies that the country’s ecological footprint has exceeded the global average bio-capacity. The consumption of natural aggregates for construction in Chile has grown by around 6.6% in the last year, with around 120 million tons being extracted. Given the above, it is important to seek alternatives that help to minimize the problem of resource scarcity, as well as the recovery of industrial by-products and/or waste. The Chilean forestry sector has also grown in recent years, generating approximately 4000 metric tons of waste in 2018, which was deposited in landfills or disposed of on forest roads. The present research is focused on the reuse and possible recovery of ash from the incineration of cellulose as a filler in bituminous mixtures. We analyze the adhesiveness of the filler/bitumen system in dry and wet states, based on the Cantabro wear loss test. The results obtained show that the limit of the relation between the volumetric concentration and critical concentration (Cv/Cs) is 1 for the addition of ash and that concentrations lower than or equal to this value present controlled losses, with 1.00 being the optimal (Cv/Cs) ratio that allows better behavior against the effect of water.

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EFFECTS OF GRAPHITE ON MECHANICAL PROPERTIES OF STONE MASTIC ASPHALT PAVEMENT

Journal of Civil Engineering and Management ◽

10.3846/13923730.2017.1374302 ◽

2017 ◽

Vol 23 (8) ◽

pp. 1013-1020 ◽

Cited By ~ 3

Author(s):

Baha Vural KÖK ◽

Mehmet YILMAZ ◽

Yunus ERKUS

Keyword(s):

Mechanical Properties ◽

Fatigue Tests ◽

Modified Bitumen ◽

Stiffness Modulus ◽

Bituminous Mixtures ◽

Mastic Asphalt ◽

Significant Difference ◽

Stone Mastic Asphalt ◽

Indirect Tensile ◽

Marshall Stability

Hot mix asphalt needs to be developed to resist particular permanent deformations like rutting and thermal cracking due to increased traffic volumes and vehicle loads. Additives such as carbon black, graphite, carbon fibers are used in the mixture or the binder for improving the mechanical features of asphalt. In this article, the effects of graphite used for developing the mechanical properties of asphalt have been investigated in mixtures tests. Therefore, Marshall stability, indirect tensile stiffness modulus and indirect tensile fatigue tests were performed to bituminous mixtures modified with three different proportions of graphite by weight of bitumen. Stone mastic asphalt mixtures which were manufactured with pure and modified bitumen were aged in different time intervals in the oven. In conclusion, it has defined that Marshall stability values have declined. It has been determined that there is no significant difference in the time-dependent deformation behavior of the original and aged samples in pure and different graphite content although the stiffness modulus and load repeat number of the samples increased with the rise of the aging time. These results shown that graphite generally used for improving the thermal properties in literature were also determined to contribute to mechanical properties of mixtures.

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Experimental Study of Tensile Properties of Styrene–Butadiene–Styrene Modified Asphalt Binders

Materials ◽

10.3390/ma14071734 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1734

Author(s):

Paweł Mieczkowski ◽

Bartosz Budziński ◽

Mieczysław Słowik ◽

Jan Kempa ◽

Wojciech Sorociak

Keyword(s):

Qualitative Evaluation ◽

Thermoplastic Elastomer ◽

Asphalt Binders ◽

Cohesion Energy ◽

Modified Bitumen ◽

Styrene Copolymer ◽

Bituminous Mixtures ◽

Styrene Butadiene Styrene ◽

Styrene Butadiene ◽

Butadiene Styrene

The requirements imposed on road pavements are ever increasing nowadays, necessitating the improvement of the properties of paving materials. The most commonly used paving materials include bituminous mixtures that are composed of aggregate grains bound by a bituminous binder. The properties of bitumens can be improved by modification with polymers. Among the copolymers used for modifying bitumens, styrene–butadiene–styrene, a thermoplastic elastomer, is the most commonly used. This article presents the results of tests conducted on bitumens modified with two types of styrene–butadiene–styrene copolymer (linear and radial). Two bitumen types of different penetration grades (35/50 and 160/220) were used in the experiments. The content of styrene–butadiene–styrene added to the bitumen varied between 1% and 6%. The results of the force ductility test showed that cohesion energy can be used for qualitative evaluation of the efficiency of modification of bitumen with styrene–butadiene–styrene copolymer. The determined values of the cohesion energy were subjected to the original analysis taking into account the three characteristic elongation zones of the tested binders. The performed analyses made it possible to find a parameter whose values correlate significantly with the content of styrene–butadiene–styrene copolymer in the modified bitumen. With smaller amounts of added modifier (approximately 2%), slightly better effects were obtained in the case of linear copolymer styrene–butadiene–styrene and for larger amounts of modifier (5–6%) radial copolymer styrene–butadiene–styrene was found to be more effective. This is confirmed by the changes in the binder structure, as indicated by the penetration index (PI).

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LABORATORY INVESTIGATION INTO THE EFFECTS OF FIBERS ON BITUMINOUS MIXTURES

Journal of Civil Engineering and Management ◽

10.3846/13923730.2013.802720 ◽

2014 ◽

Vol 21 (1) ◽

pp. 45-53 ◽

Cited By ~ 8

Author(s):

Emanuele Toraldo ◽

Edoardo Mariani ◽

Sara Malvicini

Keyword(s):

Mechanical Performance ◽

Road Construction ◽

Modified Bitumen ◽

Research Project ◽

Bituminous Mixtures ◽

Different Types ◽

Road Materials ◽

Compaction Properties ◽

Polymer Modified Bitumen ◽

Bitumen Modification

The growing need for high quality bituminous mixtures in road construction, rehabilitation and maintenance is currently satisfied by means of techniques to produce polymer-modified bitumen, or by the addition of additives to mixtures during in-plant mixing operations. A rigorous rheological approach in the study of the bitumen modification process enables researchers to rationally compare different modifying agents and to evaluate their relative efficiency for specific field applications. As far as additives are concerned, the binder is not the only element involved in the evaluation; both binding mastics and bituminous mixtures must be evaluated to get a complete understanding of the characteristics. Moreover, the advantages that may stem from the use of fibers should be carefully taken into consideration since they may offer alternative strategies for the enhancement of bituminous mixtures. As a result of these observations, the authors have devised an experimental research project focused on the analysis of the effects of different types and dosages of cellulose-based fibers on the main performance-related properties of bituminous road materials: compaction properties, volumetric characteristics and mechanical performance. This paper provides an overview of the results obtained and some details of the specific protocols followed during the research project.

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Study on Rheological Properties of Bituminous Binders and Mixtures Containing Waste Printed Circuit Boards (PCBs) and SBR Compound Modified Bitumen

Materials ◽

10.3390/ma14071697 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1697

Author(s):

Yongjun Meng ◽

Yongjie Liao ◽

Zhirong Liu ◽

Jing Chen ◽

Xiaolong Yang ◽

...

Keyword(s):

High Temperature ◽

Rheological Properties ◽

Printed Circuit Boards ◽

Absorption Peak ◽

Circuit Boards ◽

Bituminous Mixture ◽

Modified Bitumen ◽

Printed Circuit ◽

Bituminous Mixtures ◽

Waste Printed Circuit Boards

Improper handling of waste printed circuit boards (PCBs) can cause serious pollution to the water and soil environments. In order to explore a new method of recycling waste PCBs, this study investigated the effect of PCBs and butadiene styrene rubber (SBR) on the rheological properties of neat bitumen. The dynamic shear rheological (DSR) test was used to study the effect of different PCB contents on the high-temperature rheological properties of SBR-modified bitumen. Fluorescence microscopy and Fourier-transform infrared spectroscopy were used to study the microstructure change law and modification mechanism of PCB and SBR composite modified bitumen. Finally, the feasibility of the bitumen properties was verified through a test of the bituminous mixture properties. The DSR test results showed that the addition of PCBs improves the elastic recovery modulus, dynamic shear modulus, and rutting factor of SBR-modified bitumen, indicating that the high-temperature properties were improved. Infrared spectroscopy analysis revealed that a new absorption peak was generated in the infrared spectrum of the compound bitumen after the addition of PCBs, and the intensity of the original absorption peak also changed, indicating that PCBs and SBR-modified bitumen were mainly physically blended and accompanied by a weak chemical reaction. It was further found that the absorption peak of the unsaturated C=C double bond was significantly enhanced, and the increase in the content of the unsaturated bond C=C in the main chain of the polymer significantly increases the stiffness of the bitumen. Macroscopically, the high-temperature rutting resistance was improved to a certain extent. The fluorescence diagram shows that when PCBs do not exceed 10%, the PCBs can form a homogeneous structure and be dispersed in SBR-modified bitumen. The road test of PCBs and SBR composite modified bituminous mixtures showed that PCBs can significantly improve the rutting resistance and water stability of SBR-modified bitumen at high temperatures at the recommended optimum content. The crack resistance at low temperatures is weakened but still meets actual engineering requirements. The correlation analysis between the properties of bitumen and bituminous mixtures is carried out based on grey correlation theory. The results show that the index of modified bitumen has a very good guiding effect on the bituminous mixture properties. The development of PCBs and SBR composite-modified bitumen provides a new practical method for recycling waste PCBs.

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Ageing and temperature effect on the fatigue performance of bituminous mixtures

Materiales de Construcción ◽

10.3989/mc.2017.04216 ◽

2017 ◽

Vol 7 (080) ◽

pp. 126

Author(s):

T. López-Montero ◽

R. Miró

Keyword(s):

Low Temperatures ◽

Progressive Increase ◽

Fatigue Performance ◽

Relative Importance ◽

Modified Bitumen ◽

Asphalt Mixes ◽

Bituminous Mixtures ◽

Different Temperatures ◽

Strain Sweep ◽

Polymer Modified Bitumen

The ageing of asphalt mixes, together with their exposure to low temperatures, causes a progressive increase of cracking. In this paper, the effect of ageing and temperature on the fatigue of asphalt concretes made with two types of binders, conventional (50/70) and polymer modified bitumen (PMB), is studied. For this purpose, specimens previously subjected to an accelerated laboratory ageing process were tested by a strain sweep test at different temperatures (-5ºC, 5ºC and 20°C). Results were compared with the obtained from the unaged specimens showing the relative importance of ageing, temperature and type of bitumen on the parameters that determine the fatigue life of the mixture. The mixtures behaviour becomes more brittle with ageing and the decrease of temperature. However, ageing hardly has an effect on fatigue at lower temperatures. In general, mixtures made with polymer modified bitumen have a better fatigue performance to ageing and temperature.

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Experimental Study of Nano Inorganic Mineral Modified Bitumen

CICTP 2017 ◽

10.1061/9780784480915.131 ◽

2018 ◽

Author(s):

Yang Zhang

Keyword(s):

Experimental Study ◽

Modified Bitumen ◽

Inorganic Mineral

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Investigational Studies on Quantity of Salinity in Netravati River Estuary Sand-Coastal Karnataka

International Journal of Emerging Research in Management and Technology ◽

10.23956/ijermt.v6i6.243 ◽

2018 ◽

Vol 6 (6) ◽

pp. 46

Author(s):

Raveesha P ◽

K. E. Prakash ◽

B. T. Suresh Babu

Keyword(s):

Brackish Water ◽

Sea Water ◽

Salt Water ◽

Construction Material ◽

Salt Content ◽

River Estuary ◽

Sand Sample ◽

River Sand ◽

Natural Aggregates

The salt water mixes with fresh water and forms brackish water. The brackish water contains some quantity of salt, but not equal to sea water. Salinity determines the geographic distribution of the number of marshes found in estuary. Hence salinity is a very important environmental factor in estuary system. Sand is one major natural aggregate, required in construction industry mainly for the manufacture of concrete. The availability of good river sand is reduced due to salinity. The quality of sand available from estuarine regions is adversely affected due to this reason. It is the responsibility of engineers to check the quality of sand and its strength parameters before using it for any construction purpose. Presence of salt content in natural aggregates or manufactured aggregates is the cause for corrosion in steel. In this study the amount of salinity present in estuary sand was determined. Three different methods were used to determine the salinity in different seasonal variations. The sand sample collected nearer to the sea was found to be high in salinity in all methods. It can be concluded that care should be taken before we use estuary sand as a construction material due to the presence of salinity.

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