Increasing the content of Reclaimed Asphalt in hot asphalt mixtures is one of the current issues in road construction, to which society's attention is paid. The higher content of Reclaimed Asphalt brings higher technological demands not only for the production of asphalt mixture plants, but also for the handling of materials in general. The benefit for higher demands on asphalt mixture production is the subsequent reduction of the environmental burden associated with the construction of road infrastructure caused by the mining industry and use of natural resources. The dissertation is focused on studying recycling agents which are used in the production of asphalt mixtures containing Reclaimed Asphalt. Emphasis is put on comparing the properties of recycled binders with paving bitumen and binders from Reclaimed Asphalts whereas the effect of repeated recycling is taken into account. A large part of the thesis is devoted to the design of the optimal dosage of recycling agents. Certain findings were used to draw a methodology describing the design of dosing of these agents. At the same time, the properties and behaviour of the recycling agents themselves were evaluated.

Asphalt is a material used to lay several different types of roads. It has been used in Sweden for more than 200 years. During these years, the work with asphalt has changed, ingredients have been replaced and manufacturing methods have been updated. In modern asphalt, bitumen is used as a binder. It is extracted from crude oil, which is a fossil substance that will not exist forever and also has a bad impact on the environment, therefore people have worked to find new ideas. This report will be about two methods of working for a more sustainable future. The construction and real estate company NCC works with asphalt recycling and the construction company Peab is researching if lignin can be used as a binder. The purpose of this report is to find out which of these methods leaves the least climate footprint. Asphalt is 100% recyclable, but to only use recycled asphalt in new production is not possible, as the quality does not measure up. Lignin is obtained from residual products from the forest industry, which means it is fossil-free. The work with lignin is currently at the research level, so it is not used as standard yet. In order to obtain a result, interviews with people who work at Peab and NCC have been conducted. These people have been able to answer our questions as they work on the topic. Recycling has been used for several decades, therefore the work has come significantly further than the work with lignin which has only been in progress since 2018. For this reason it is difficult to determine which method is most sustainable in the long run. What has been concluded is that when lignin is mixed with bitumen, the durability increases, hence the life-span. We have come to the conclusion that both companies think it is important with recycling, but also that they can see a future with a shortage of recycled asphalt. / Asfalt är ett material som används för att lägga flera olika typer av vägar. Den har använts i Sverige i mer än 200 år. Under dessa år har arbetet med asfalt förändrats, man har bytt ut innehåll och uppdaterat tillverkningsmetoder. I modern asfalt används bitumen som bindemedel. Den utvinns ur råolja vilket är ett fossilt ämne som inte kommer finnas för evigt och har även dålig påverkan på miljön, därför jobbar man för att hitta nya idéer. Denna rapport kommer handla om två metoder där man arbetar för en mer hållbar framtid. Återvinning av asfalt som bygg- och fastighetsföretaget NCC använder sig utav och lignin som bindemedel något som bygg- och anläggningsföretaget Peab forskar på. Syftet med denna rapport är att ta reda på vilken av dessa metoder som lämnar minst klimatavtryck. Asfalt är 100% återvinningsbar men att endast använda återvunnen asfalt i nyproduktion är inte möjligt, då kvaliteten inte håller måtten. Lignin får man fram ur restprodukter från skogsindustrin, den är alltså fossilfri. Arbetet med lignin är i nuläget på forskningsnivå, därför används den inte som standard ännu.  För att få fram ett resultat har bland annat intervjuer med personer som jobbar på Peab och NCC gjorts. Dessa personer har kunnat besvara på våra frågor då de arbetar med ämnet. Återvinning har använts i flera årtionden därför har arbetet kommit betydligt längre än arbetet med lignin som har pågått sedan 2018. Av denna anledning är det svårt att i nuläget avgöra vilken metod som är mest hållbar i längden. Det man har kommit fram till är att när lignin blandas med bitumen ökar hållbarheten, därmed livslängden. I slutsatsen kommer vi fram till att båda företag tycker det är viktigt med återvinning, men även att de kan se en framtid med brist på returasfalt.

Subject of this diploma thesis is to describe the effect of adding different amount of aged binder recovered from RAP on the change of properties of polymer modified bitumen. The RAP containing unmodified bitumen and the RAP where we can expect bitumen modification are used to recover binder. The binder obtained from RAP is dosed into the virgin binder in amount of 15 %, 30 % and 50 %. The methods of recycling of flexible pavements, extraction and regeneration of asphalt binders, rejuvenating of their properties and methods of empirical and functional laboratory tests are described in the theoretical part. The practical part deals with evaluating and comparison of the results mixed binders properties.

In the present thesis we study and compare different viscoelastic rate-type fluid models capable of describing response of geomaterials such as asphalt. Using new thermodynamic approach proposed by Rajagopal and Srinivasa (2000) we derive several classes of non-linear viscoelastic models that generalize standard Oldroyd-B and Burgers models. We show that the new models achieve better results in fitting experimental data with asphalt than the previously considered models (Oldroyd-B, Burgers, Rajagopal and Srinivasa (2000)). In particular they are able to capture the behavior of asphalt observed recently in experiments (torque overshoot and two relaxation mechanisms), which is not possible to describe by the other models. Using both the standard and the newly derived models we compute full simulations of viscoelastic flow with the finite element method in fixed domains and incorporating the Arbitrary Lagrangian-Eulerian description also in deforming domains. For example, we study rolling of asphalt or creation of ruts in the road with the real material parameters obtained by fitting the experiments. Powered by TCPDF (www.tcpdf.org)

The aim of this diploma thesis is theoretical knowledge of the problems rich bottom layer and practical part of comparison of three asphalt mixtures for base layers using common road bitumen and modified rubber granulate. Selected functional laboratory tests (low temperature, fatigue resistance, bulk density) and stiffnes modules are performed on these mixtures and the results are compared to each other.

The diploma thesis deals with the use of recycled polymers in asphalt mixtures. In the theoretical part of the thesis there is discussed the global issue of plastic waste including the experience of foreign countries, where this technology has already been introducted and used. The practical part is devoted to the proposal of using recycled plastic in asphalt mixture, description of used laboratory tests and the evaluating the effect of low-density polyethylen (LDPE) on the asphalt mixture type AC. There were performed tensile strenght tests, water resistant tests and stiffness modulus tests in the laboratory (E). The output of this work is an evaluation of measured values, processing of results and their interpretation depending on the possible use of this technology in Czech republic.

Det här arbetet handlar om asfaltbetongblandningar och hur variationen av dessa vid projektering påverkar vägarnas dimensionering i överbyggnaden mer specifikt bärlagret. Arbetet är baserat på litteraturstudier av den senaste teorin kring dimensionering av asfaltbetongblandningar i väglager samt tillhörande kravskrifter både från svenska och amerikanska myndigheter. Den inledande delen i examensarbetet omfattar bakgrunden till vägdimensionering. Inledningsvis behandlas materialet asfaltbetong och derss egenskaper för att sedan gå vidare till allmänt om vägar, hur de utformas, vägens funktionella egenskaper och skador som kan uppstå. Detta ska ge läsaren tillräckligt med bakgrund för att följa med i resten av arbetet där man kan läsa mer ingående om deformationsskador och vilka parametrar som är till stor vikt när man studerar skador som uppstår i asfaltbetongen samt relationen till dem egenskaper bitumen har. Rapporten avslutas med att resonera kring eventuella problem kring dimensioneringsmetoder samt betydelsen av blandningens hållfasthetsegenskaper och hur de påverkar vägarnas tjocklek. Slutsatsen i rapporten är att asfaltbetongblandningen har en betydelse för dimensionering av bärlager och att det kan vara någonting att beakta oftare vid vägdimensionering speciellt vid blandningar som skiljer sig mycket från standardvarianterna. / This essay is about bitumen concrete pavement mixtures and how the variation of these affects the design of the superstructure of the road during the design-stadium, more specifically the pavement. The essay is based upon studies of literature written about the latest theory of asphalt concrete design for roads as well as the texts with regulations from Swedish and American government agencies. The introductory parts of the essay consist of the background to road design. Initially bitumen concrete and its characteristics are discussed and move on to general information about roads, how they are designed, the roads serviceable characteristics and finally the damage that can develop. This is meant to give the reader enough background to follow the rest of the essay where you can read more about deformation and which parameters that are of importance when you study deformation in bitumen concrete as well as the relation between the characteristics of bitumen concrete and bitumen. The essay is then finished with a argumentation about eventual problems with design methods and the significance of the bitumen concrete mixture’s strength parameters and how they affect the thickness of the road superstructure. The conclusion is that the asphalt concrete mixture has an impact on the design of the pavement of the road and that it should be something to take into account more often in road design, especially when you are using a mixture that differs much from the standard mixtures.

The theoretical part of the diploma thesis recapitulates the existing literature in the field of recycling asphalt mixtures with a higher content of RAP (Reclaimed asphalt pavement). The practical part of the diploma thesis examines changes in the properties of asphalt mixtures with a higher content of RAP, due to changes in mixing time. Five mixtures have been proposed for this research. It is an asphalt mixture intended for the road abrasive layer (ACO 11+). Reference mixture "A" without RAP, with a standard mixing time of 25 seconds. Mixture "B" with 40% RAP, without rejuvenator, with an extended mixing time of 40 seconds. Mixture "C" with 40% RAP, with rejuvenator and standard mixing time. Mixture "D" with 40% RAP with rejuvenator and extended mixing time of 40 seconds. Mixture "E" with 40% RAP, with rejuvenator and extended mixing time of 55 seconds.

Today’s society is highly reliable on a working road infrastructure, which is because of collective efforts already built in terms of main net of roadways, and the attention is now paid to its service life primarily from a point of view of a climate change which is causing more frequent temperature extremes. This thesis sets its goal to perform basic tests for bitumen, especially ones dealing with low temperature properties, on types of bitumen usually used in out day to day world and asphalt mixtures made with those types of bitumen. The theoretical part talks about the basic definition of bitumen and studies performed on the similar issue. Practical part of the thesis is focused on performing the tests of bitumen and asphalt, which include but are not limited to, penetration test, softening point test, critical temperature detected by method by Fraasse and the bending beam rheometer and the test to set critical temperature of asphalt by using TSRST. At the end of the thesis the evaluation of results and its mutual correlation is performed.

The subject of this diploma thesis is paid attention to the influence of different dosing of R-material containing unmodified asphalt on the properties of asphalt concrete for abrasive layers (AC011 +) bonded with polymer highly modified asphalt (binder type HiMA). The properties of asphalt mixtures will be evaluated by means of the stiffness modulus test and the test of low-temperature properties by a uniaxial tensile test.