Influence of aggregates on permanent deformation of asphalt

التفاصيل البيبلوغرافية
العنوان:	Influence of aggregates on permanent deformation of asphalt
بيانات النشر:	KTH, Jord- och bergmekanik Stockholm 2020
تفاصيل مُضافة:	Lira Miranda, Bernardita Francisca
نوع الوثيقة:	Electronic Resource
مستخلص:	One of the most common failure modes for asphalt pavements is the occurrence of permanent deformation on the wheel path. This leads to not only other distresses, such as potholes and stripping, but also decreases substantially road safety and increases maintenance costs. Resistance to permanent deformation of asphalt mixtures depends mostly on the aggregates, bitumen and air void content of the mixture. Mineral aggregates are the major component of asphalt mixtures, representing more than 90 % of the weight. The structure formed by the aggregates within the mixture depend highly on the size distribution, shape and texture of the aggregates. To manipulate the characteristics of the mineral aggregates is usually considered the most economical and convenient way to improve asphalt mixture performance. The study presented in this thesis has investigated the influence of aggregate particles on the resistance to permanent deformation of asphalt mixtures. In the theoretical part, some pre-existing models have been considered and then further developed to obtain a framework able to characterise asphalt mixtures based on their aggregate gradation and relate these properties to performance. In the gradation-based framework two structures are identified: the primary structure, which provides the load-bearing capacity, and the secondary structure, which contributes with stability and durability. The experimental part has focused mainly on testing the assumptions included in the developed framework with regards to aggregates size distribution, gradation, and shape. Two series have been tested, one with varying aggregate gradation and one with varying flakiness index. All bitumen parameters and aggregate source have been kept constant for each series. Results from the first series show that the aggregate gradation, especially the coarse fraction, has a significant influence on the resistance to permanent deformation as measured with the wheel tracking test. Mixtures where even te Permanenta deformationer är ett av de vanligaste problemen för asfaltsvägar och innebär att trafikrelaterad belastning trycker ihop eller omfördelar asfalten så att spårbildning uppstår vid ytan. Deformationer minskar trafiksäkerheten och ökar kostnaderna för beläggningsunderhåll, och kan även öka risken för andra problem som t.ex. potthål. Resistens mot permanenta deformationer påverkas mest av bitumentyp och halt, stenmaterialets sammansättning och beläggningens hålrumshalt. Stenmaterialet utgör huvudkomponenten i asfaltmassor och omfattar normalt mer än 90 % av vikten. Stenmaterialets struktur i blandningen beror på kornstorleksfördelningen samt form och textur hos partiklarna. Att manipulera egenskaperna hos stenmaterialet, främst fördelningen, anses vanligtvis vara det mest ekonomiska och fördelaktiga sättet att förändra och förbättra asfaltbeläggningars funktion.Projektet presenterat i denna avhandling har undersökt inverkan av stenmaterialets sammansättning på permanenta deformationer hos bitumenbundna lager. I den teoretiska delen har existerande modeller studerats och vidareutvecklats till en mer generaliserad modell (gradation-based framework) i syfte att karaktärisera asfaltbeläggningar baserat på stenmaterialets sammansättning. Parametrarna från modellen har sedan använts för att prediktera provade asfaltbeläggningars funktion. I gradation-based framework identifieras två strukturer: den primära strukturen, som ger lastbärande kapacitet, och den sekundära strukturen, som bidrar med stabilitet och hållbarhet. Den experimentella delen har huvudsakligen fokuserat på att prova antagandena i den teoretiska modellen med avseende på kornstorleksfördelning och form. Två serier har testats, en med varierande kornstorleksfördelning och en med varierande flisighetsindex. Alla bitumenparametrar och stenmaterialets ursprung har hållits konstanta i respektive serie.Resultat från den första provningsserien visar att hela stenmaterialets fördelning, särskilt den grova f QC 20201116
مصطلحات الفهرس:	Asphalt, deformation, rutting, gradation, flakiness index, Asfalt, kornstorleksfördelning, flisighetsindex, permanent deformation, spårbildning., Infrastructure Engineering, Infrastrukturteknik, Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text
URL:	http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-285775 TRITA-ABE-DLT ; 2035
الإتاحة:	Open access content. Open access content info:eu-repo/semantics/openAccess
ملاحظة:	application/pdf English
أرقام أخرى:	UPE oai:DiVA.org:kth-285775 0000-0001-6135-3238 urn:isbn:978-91-7873-708-6 1235094537
المصدر المساهم:	UPPSALA UNIV LIBR From OAIster®, provided by the OCLC Cooperative.
رقم الأكسشن:	edsoai.on1235094537
قاعدة البيانات:	OAIster

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