Effect of hot-mix asphalt temperature on compaction

V magistrski nalogi je obravnavan vpliv temperature, ki jo ima vroče valjana asfaltna zmes ob vgradnji, na njeno doseženo zgoščenost po koncu vgradnje. V nalogi je velik poudarek na zaznavanju temperaturno segregiranih lokalnih mest. To področje smo najprej proučili s pomočjo tuje in Slovenske literature, ter ugotovitve strnjeno prikazali. V nadaljevanju smo na realnem projektu sanacije hitre ceste izvedli meritve. S pomočjo ustrezne merilne opreme smo načrtno merili zgoščenost na predhodno označenih lokalnih hladnih mestih. Medsebojni vpliv temperature ob vgradnji in dosežene zgoščenosti po koncu vgradnje, smo ugotavljali pod enakimi pogoji vgradnje. Vpliv temperature na zgoščenost asfaltne zmesi smo preverili za štiri različne funkcionalne asfaltne plasti. Uporabili smo tudi različne metode merjenja. Proučili smo problematiko temperaturne segregacije v asfaltnih zmeseh z uporabo IR termografije pred valjanjem in izvedli meritve zgoščenosti vgrajenega asfalta po valjanju. Meritve zgoščenosti smo izvajali s porušno (odvzem jeder) in z neporušno metodo (elektromagnetna in izotopska sonda). Iskali smo povezanost med temperaturo in gostoto asfalta, ker nas je zanimalo, ali bi lahko na osnovi temperature sklepali kakšna bo pričakovana gostota asfalta. Naša hipoteza je bila, da večja kot je temperatura, večja je zgoščenost v temperaturnem območju, ko je asfalt »tekoč« in nesegregiran. Prav tako smo iz dobljenih rezultatov želeli ugotoviti, ali na lokalno ohlajenih mestih asfaltne zmesi še vedno dosegamo minimalno stopnjo zgoščenosti, ki jo predpisuje slovenska tehnična regulativa. V zadnjem delu naloge so podani rezultati meritev, ugotovitve, predlogi za izboljšave in komentar.The aim of master\u27s thesis was to determine the influence of the temperature of hot-rolled asphalt mixture during installation on its achieved density after the end of installation. The main emphasis was on the perception of temperature-segregated local sites. We first studied this field with the help of foreign and Slovenian literature, and then summarized the findings. We performed measurements on a real project for the repair of the highway. With the help of appropriate measuring equipment, we systematically measured the density in pre-marked local cold places. The interaction between the temperature at installation and the achieved density after the end of installation was determined under the same installation conditions. The influence of temperature on the density of the asphalt mixture was examined for four different functional asphalt layers. We also used different measurement methods. We studied the problem of temperature segregation in asphalt mixtures using IR thermography before rolling and performed measurements of the density of embedded asphalt after rolling. Density measurements were performed by the destructive (core removal) and non-destructive methods (electromagnetic and isotope probe). We looked for a relationship between temperature and asphalt density because we were interested in whether we could deduce the expected asphalt density based on temperature. Our hypothesis was that the higher the temperature, the greater the density in the temperature range when the asphalt is “liquid” and unsegregated. We also wanted to determine from the obtained results whether the locally cooled places of the asphalt mixture still achieve the minimum level of compaction prescribed by Slovenian technical regulations. The last part of the paper presents the results of measurements, findings, suggestions for improvements and comment