Factors contributing to stripping and stone loss of ultra-thin friction courses, and their remedy.
dc.contributor.advisor | Jenkins, Kim J. | en_ZA |
dc.contributor.author | Baartman, Quinton | en_ZA |
dc.contributor.other | Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering. | en_ZA |
dc.date.accessioned | 2024-02-21T12:12:39Z | en_ZA |
dc.date.accessioned | 2024-04-26T14:33:27Z | en_ZA |
dc.date.available | 2024-02-21T12:12:39Z | en_ZA |
dc.date.available | 2024-04-26T14:33:27Z | en_ZA |
dc.date.issued | 2024-03 | en_ZA |
dc.description | Civil Engineering | en_ZA |
dc.description.abstract | ENGLISH ABSTRACT: Asphalt surfacings are versatile and durable materials and gives a smooth and robust layer. These surfacings are commonly used in road construction, parking lots, and driveways. It provides a cost-effective solution with good resistance to wear and weathering. An ultra-thin friction course (UTFC) is an example of a functional surfacing. The functional requirements of UTFCs include providing a wearing surface, reduction in noise, increased wet skid resistance, and in-layer drainage. UTFCs can be opened to traffic faster than conventional hot-mix asphalt (HMA) and can accommodate high speed traffic better than conventional HMA. UTFCs are paved with a special self-priming paver. Asphalt mixtures would typically have voids percentages that range from 3- 5%. UTFCs are designed to be permeable with an increased percentage of voids, that can range from 12- to 20%. UTFCs are designed to last for 5 – 8 years. There are currently no guidelines on how to perform maintenance on UTFCs once it has come to the end of its life. This is the gap that this research is attempting to fill. The primary goal of this research was to establish whether it is worthwhile to perform maintenance on an open structure such as UTFCs. This research also aims to provide some guidance for UTFC maintenance. An arterial road in Gauteng was paved with an UTFC and premature failures of stripping and ravelling was observed. These failures are moisture induced. Moisture has a degrading impact on asphalt and causes the gradual breakdown of the mix integrity. The road was divided into five different sections (Sections A to E) and each section was treated with a different method. Three cores were taken from each section before the application of treatment as well as after treatment was applied. The applied treatment options were: • Section A: Ralumac used for rut filling (7 mm NMAS) followed by Ralumac overlay (5 mm NMAS) • Section B: Fogspray (0.5 l/m2) followed by Ralumac overlay (5 mm NMAS) • Section C: Fogspray (1 l/m2) • Section D: Onyx (2 x 1.1 l/m2) • Section E: Solvent based rejuvenator (0.34 l/m2) The primary testing method used in this research is permeability. The permeability testing involved, air-, Marvil-, and high-pressure permeability testing. The Marvil test, which is an in-field permeability test, was modified for laboratory environment. It was modified to only test for vertical permeability and to test horizontal and vertical permeability at the same time. The high-pressure permeameter (HPP) was developed by Stellenbosch University in 2016. The typical testing are pressures of 100- and 150 kPa. Computed Tomography (CT) scanning also formed part of this research, where void- and permeability analysis was performed. CT analysis aided in understanding the inner nature for the cores as well permeability correlations. Binder was extracted and recovered from the treated cores of Sections C, D, and E. Rheological testing of the binder was conducted using the bending beam rheometer (BBR) and the dynamic shear rheometer (DSR) and master curves were created. FTIR of the recovered binder was performed as well. These binder tests were included to investigate how rejuvenation methods impact binder performance and aging. The UTFCs were found to be more permeable horizontally as opposed to the vertically. In some cases, the samples were 100% of the flow contributed to horizontal permeability. Little to no permeability in the vertical direction speaks to the sealing off capability of the bond coat. The results mainly found that the Ralumac applications in Section A and B led to the most significant reductions in permeability, followed by Section C and D. Section E mainly caused slight to major increases in permeability. It was also found that the Ralumac treatment can be applied in the long-term maintenance of UTFCs, where stone loss has been initiated. This can then serve as a substrate for future overlays. The sprays in Sections C and D were found to be more useful in the short to medium term maintenance of UTFCs. | en_ZA |
dc.description.abstract | AFRIKAANSE OPSOMMING: Asfalt bedekkings is veelsydige en duursame material en gee ‘n gladde lag. Hiedie bedeekings word algemeen in die konstruksie van plaveisels en parkeerterreine gebruik. Dit bied ‘n koste-effektiewe oplossing met goeie weerstand teen verwering. ‘n Ultra-dun wrywingslaag (UDWL) is ‘n funksionele laag. Die funksionele veresites van UDWLe sluit in die verskaffing van ’n dra-oppervalk, vermindering in geraas, verhoogde natglyweerstand en dreinering binne die laag. UDWLs kan vinniger oopgemaak word vir verkeer as tradisionele asfalt en kan hoëspoed verkeer beter akkommodeer. UDWLe word gebou met ‘n sefaanvullende plaveisel masjien. UDWL is ontwerp om verhoogde deurlaatbaarheid te hê weens die verhoogde persentasie van lugruimtes, wat kan wissel tussen 12- to 20%. Asfalt het tipies 3- to 5% lugruimtes. Daar is tans geen riglyne oor hoe om UDWL te onderhou wanneer dit die einde van sy leeftyd bereik. Dít is die gaping wat hierdie navorsing probeer vul. Die hoofdoel is om te bepaal of dit koste effektief is om instandhouding uit te voer op oop strukture soos UDWLe. Hierdie navorsing mik ook om leiding te verskaf vir UDWLe instandhouding. ‘n Hoofpad in Gauteng het ‘n UDWL as bedekking en vroeë tekens van bitumenstroping en klipverlies is waargeneem. Hierdie tekens word deur vog geïnduseer. Vog het ‘n afbrekende impak op asfalt en versoorsak die geleidelike afbreek van die integriteit van die mengsel. Die pad is in vyf verskillende afdelings verdeel (Afdelings A to E) en elke afdeling is behandel met ‘n verskillende metode. Drie kerns is uit elke afdeling geneem voor die toediening van die behandeling en ook na behandeling. Die toegepaste behandelingopsies was: • Afdeling A: Ralumac gebruik vir spoorvulling (7 mm NMAS) gevolg deur Ralumac-oorleg (5mm NMAS) • Afdeling B: Missproei (fogspray) (0.5 l/m2) gevolg deur Ralumac-oorleg (5 mm NMAS) • Afdeling C: Missproei (1 l/m2) • Afdeling D: Onyx (2 x 1.1 l/m2) • Afdeling E: Oplosmiddelgebaseerde verjonger (0.34 l/m2) Die primêre toetsmetode wat gebruik was, is deurlaatbaarheid. Die deurlaatbaarheidstoetse het betsaan uit lug-, Marvil-en hoëdruk-deurlaatbaarheidstoetse (HDD). Die Marvil toets, wat ‘n veld deurlaatbaarheidstoets is, is aangepas vir laboratorium omstandighede. Dit is aangepas om slegs vertikale deurlaatbaarbeid te toets. Dit is ook aangepas om vir horisontale en vertikale deurlaatbaarheid terselfdetyd te toets. Die HDD is in 2016 ontwikkel deur Stellenbosch Universiteit. Dit toets by 100- en 150 kPa. Skandering van die kerns deur middel van rekenaartomografie het ook deel gevorm van die navorsing. Die analise van lugruimtes and deurlaatbaarheid is uitgevoer. Bitumen is onttrek en herwin uit die behandelde kerns van Afdelings C, D, en E. Hierdie skandering het gehelp om die interne struktuur van die kerns te bestudeer. Reologiese toetse was uitgevoer op die bitumen met behulp van buigbalkreometer (BBR) en die dinamiese skuifreometer (DSR) en meesterkurwes is geskep. FTIR van die herwonne bitumen is ook uitgevoer. Die toetse op die bitumen het gehelp om die impak van die verskillende metodes op die bitumen te assesseer. Daar is gevind dat UDWLe meer deurlaatbaar is in die horisontale rigting as in die vertikale rigting. In sommige gevalle het 100% van die vloei bygedra tot horisontale deurlaatbaarheid. Min to geen deurlaatbaarheid in die vertikale rigting gee ‘n indikasie van die vermoë van die bindlaag om die UDWL te verseël. Die resultate het bevind dat Ralumac-toedienings in Afdelings A en B gelei to die mees betekenisvolle verlagings in deurlaatbaarheid, gevolg deur Afdelings C en D. Afdeling E het hoofsaaklik geringe verhogings in deurlaatbaarheid veroorsaak. Daar is ook gevind dat Ralumac toegepas kan word in die lantermyn onderhoud van UDWLe, waar klipverlies alreeds begin het. Dit kan ook dien as ‘n substraat vir toekomstige oorlegsels. Daar is gevind dat die bespuitings in C en D meer bruikbaar is in die kort- tot mediumtermyn onderhoud. | en_ZA |
dc.description.version | Masters | en_ZA |
dc.format.extent | xxv, 223 pages : illustrations | en_ZA |
dc.identifier.uri | https://scholar.sun.ac.za/handle/10019.1/130354 | en_ZA |
dc.language.iso | en_ZA | en_ZA |
dc.language.iso | en_ZA | en_ZA |
dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
dc.rights.holder | Stellenbosch University | en_ZA |
dc.subject.lcsh | Asphalt concrete -- Permeability | en_ZA |
dc.subject.lcsh | Roads -- Design and construction | en_ZA |
dc.subject.lcsh | Ultra-thin friction course | en_ZA |
dc.title | Factors contributing to stripping and stone loss of ultra-thin friction courses, and their remedy. | en_ZA |
dc.type | Thesis | en_ZA |
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