The report describes a test road with Porous Asphalt (PA) on E4, Huskvarna. Construction contract form of the object was a turnkey contract, including requirements on noise reduction during operation time. In the summer of 2010 two layers of porous asphalt (double layer) were laid at a distance of 2.7 km by Huskvarna. In connection with the performance of the pavement were also a number of test sections into the object. A working group with representatives from contractors (Svevia), suppliers (Nynas), researcher (VTI) and Transport Administration had started up in early 2010 with the aim to develop a concept for double layer of porous asphalt with as good technical and acoustic properties as possible. Past experience showed relatively short lifetimes of these types of pavement and damage related to durability occurred in early stages. VTI has performed noise measurements according to the CPX method (ISO/DIS 11819-2) years 2010, 2011, 2012, 2013 and 2014. The measurements have been performed in all lanes and directions and gave the following results: · 2010: Noise reduction is 7 to 8 dB(A). · 2011: Noise Reduction 7 to 8 dB(A). · 2012: Noise Reduction 6.5 to 7.5 dB(A). · 2013: Noise Reduction 6 to 7 dB(A). · 2014: Noise Reduction 3 to 6 dB(A). The change of 3 dB(A) from 2014 compared with 2013 is connected to the lane K1 where the road was sealed in autumn 2013. The pores may have partially obstructed by the applied adhesive but also by road dirt. The drainability conducted in 2014 also show poorer drainage capacity compared with previous measurements. Drill cores from the road will also be examined for road dirt in the pores.

A round robin was carried out by seven different laboratories in Sweden for four different types of bituminous binders, two harder bitumen and two soft bitumen. The purpose of the round robin test was to compare the viscosity methods using capillaries against the new variant with a rotating spindle viscometer. Apart from these methods the aging characteristics was also tested but later not evaluated. Much data were collected from different variations on these analyzes and the focus has been on evaluating data from EN 13302, EN 12595 and EN 12596, which was the main purpose of the round robin. The evaluation has focused on the reproducibility for the various methods compared with the precision in the different standards. The variation in the result for the method SS-EN 13302 was generally lower in this round robin test compared to the precision in the standard while the variation for the SS-EN 12595 and SS-EN 12596 generally was higher.

I denna sammanställning redovisas enskilda värden, medelvärden samt värden på repeter- och reproducerbarhet. Utvärdering och eventuella åtgärder hanteras av metodgruppen. Det pågår ett projekt i Sverige finansierat av Trafikverket och SBUF som syftar till att bedöma täckningsgraden med hjälp av bildanalys. De prover som ingått i denna ringanalys har även bedömts med bildanalys (bilaga 4). Man kan konstatera att bildanalys ännu inte löst problemet med bedömning av täckningsgrad. T.ex. så bedöms täckningsgraden efter 48 tim konsekvent (dvs. för alla olika provmaterial) vara högre än efter 24 tim, vilket bedöms vara ologiskt. Förhoppningsvis kan tekniken förfinas så att vi kan nå fram till en objektiv bedömning av täckningsgrad med hjälp av bildanalys. Eftersom spridningen i resultaten blev mycket stor utfördes även en tolkning med hjälp av fotografier. Fyra bilder (tagna i bildanalysprojektet) mailades till de deltagande laboratorierna. (bilaga 5). Tanken var att om alla laboratorier bedömer samma bilder så kan man avgöra om svårigheterna ligger i provhanteringen eller i själva bedömningen av täckningsgrad. Spridningen i resultat blev här lika stor som i själva ringanalysen, så vår bedömning är att det inte bara är den subjektiva bedömningen av täckningsgrad som är problemet med denna metod utan att även provhanteringen har stor inverkan. (Några laboratorier klagade dock på att stenarna inte låg under vatten på de fotografier som mailades ut vilket metoden säger att de ska göra vid bedömningen av täckningsgrad).

This profiency testing has mainly been carried out to assess whether the changes introduced in the latest version of the Prall Standard, EN 12697–16: 2016, has improved the precision of the method.

22 laboratories participated, 16 Swedish and 6 from other Nordic countries, where the studded tires occur. The results show that the spread in the results between different laboratories is around the same level as in previous round Robin tests despite measures taken to improve the precision of the method.