Various additives to asphalt binders and asphalt mixtures improving their properties are being used more and more frequently in order to improve the durability of road pavements. Such additives include various types of fibres, including aramid fibres. Tests concerning the impact of aramid fibre addition on the properties of selected asphalt mixtures have been described herein. Two types of asphalt mixtures were assessed: high modulus asphalt concrete (HMAC) and stone mastic asphalt (SMA). The examined asphalt mixtures were assessed with regard to: resistance to rutting, resistance to water and frost as well as fatigue resistance. The conducted tests showed relatively small impact of aramid fibre addition on the improvement of some assessed properties of the analysed asphalt mixtures. The obtained results were also compared to results of the tests conducted by the other research team concerning the impact of aramid fibre addition on the properties of the other types of asphalt mixtures.
STRESZCZENIEW artykule przedstawiono wyniki badań składu morfologicznego odpadów komunalnych zbieranych w sposób selektywny w dwóch typach gmin: dużej gminy wiejskiej z terenu województwa mazowieckiego oraz gminy wiejsko-miejskiej położonej w województwie lubelskim. System odbioru odpadów segregowanych w ww. gminach były praktycznie takie same. Zebrane odpady zostały poddane segregacji na pięć podstawowych frakcji materiałowych (tworzywa sztuczne, metale, papier i tektura, opakowania wielomaterialowe oraz szkło), z podziałem na 17 podfrakcji. Łącznie ocenie składu morfologicznego poddano ponad 400 Mg odpadów. Proces wyselekcjonowania wybranych frakcji został przeprowadzony metodą ręcznego sortowania odpadów opakowaniowych. Sortowanie odpadów prowadzono w sezonie letnim w 2015 roku, przez okres 4 miesięcy. Przedstawione wyniki nie wykazały znaczących różnic w składzie morfologicznym badanych odpadów w obu gminach, a frakcją w nim dominującą była makulatura mieszana. Stwierdzono natomiast nieprawidłową segregacją odpadów "u źródła".Słowa kluczowe: selektywna zbiórka, odpady komunalne, segregacja odpadów ABSTRACTThe article presents the results of the analysis of morphological composition of municipal waste collected selectively in two municipalities: a large rural municipality in the Mazovian voivodeship and a rural-urban municipality located in the Lubelskie voivodeship. The segregated waste collection systems were practically the same in both communities. The collected waste was sorted into five basic fractions (plastic, metal, paper and cardboard, composite packaging, and glass) and divided into 17 sub-fractions. In total, over 400 Mg of waste was analysed in terms of its morphological composition. The process of separating selected fractions was performed by manually sorting the packaged waste. The study was conducted in the course of four months of the summer of 2015 and was aimed at examining the composition of waste depending on the type of municipality. The presented analyses showed no significant differences in the morphological composition of waste in both municipalities, and revealed mixed waste paper as the dominant fraction. The study showed, however, the problem of improper waste segregation at source.
The goal of the research was to investigate the retention capacity of six green roof models (SHP1, SHP2, SHP3, SH, S, and SP) constructed with the use of the square-shaped plastic trays, Floradrain FD 25 drainage elements, SF filter sheets, and the specified extensive substrates (with or without the hydrogel amendment). The SHP1 and SHP2 models were constructed in March 2017, SHP3 and SHin November 2017, while S and SPin April 2018. Four models (SHP1, SHP2, SHP3, and SP) contained the plants (the goldmoss stonecrop Sedum Acre), whereas two models (S and SH) did not contain the vegetation. The substrates of SHP1, SHP2, SHP3, and SH models contained the hydrogel admixtures. The investigations were conducted with the use of simulated (and partially natural) precipitations. The water retention capacity of each green roof model was established based on the difference between the precipitation volume and the volume of runoff from a model. The results show that green roofs can be useful stormwater management tools. The calculated stormwater retention rates ranged from 29.50% to 85.15%. In most cases, the best water retention capacity was exhibited by the SHP3 model, constructed in November 2017 and planted in April 2018, containing the substrate amended with superabsorbent (cross-linked potassium polyacrylate). The similarly constructed SHP1 and SHP2 models, which were built in March 2017, in some cases had lower water retention capacity. These models contained older hydrogel and were overgrown with older, smaller, and worse looking plants, partially supplanted by mosses. Such results indicate that the efficiency of hydrogel may decrease over time. In many cases, the S (not vegetated, without hydrogel), SH (not vegetated, with substrate containing hydrogel), and SP (vegetated, without hydrogel) models had slightly lower water retention capacity. The results of investigations indicate that there was a relatively strong positive linear correlation between the retention depth and duration of the antecedent period elapsed from the preceding total (or substantial) saturation of the green roof models (labelled in this article as period since total saturation-PSTS). The weather conditions i.e. air temperature and relative humidity as well as PSTS are very important parameters that influence the retention capacity of the green roof models. The result show that duration of PSTS can be stronger correlated with the retention depth than antecedent dry period (ADP) elapsed from the end of last precipitation, regardless of its depth and intensity.
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