17 research outputs found

    Wodoodporność recyklowanej podbudowy z asfaltem spienionym w aspekcie składu spoiwa drogowego

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    The paper describes research results of recycled base which was performedin a cold deep recycling technology with foamed bitumen and different type of hydraulicmixed binder in the aspect of water resistance. An individual design of a composition of abinder enables to achieve a precise adjustment of a binder’s impact to local conditions andrequired parameters of a recycled base. The design a recycled base with foamed bitumensimulated a cold deep recycling process with materials from existing crushed bituminouspavement layers ("technology in-situ"). To produce the foamed bitumen a road bitumen ofpenetration grade 50/70 was used. Moreover, the following mineral components werecategorised as a waste material: reclaimed asphalt pavement, 0/31,5 mm aggregate andaggregates for soil gradation improvement 0/4. A composition of the recycled base consisted of the binders prepared in the laboratory as a result of a mix of three basic components.The percentage of individual road binders was determined in line with the plan of thesimlex-centroid experiment. For the purpose of determining an influence of such a hydraulicroad binder on the water resistance in recycled base, the following tests were carried out:void contents Vm, tensile strength ratio TSR (water resistance). Additionally, an evaluationof increase of indirect tensile modulus (IT-CY) was conducted. On the basis of the testresults, a varied impacts of tested hydraulic road binders on mechanical properties andwater resistence of recycled base with foamed bitumen were observed. On the basis of theplan of the experiment, it was possible to determine the recommended road binder composition that enabled to obtain the water resistance in the recycled base with foamed bitumenW referacie przedstawiono rezultaty badań recyklowanej podbudowywykonanej w technologii recyklingu głębokiego na zimno z asfaltem spienionym orazspoiwem mieszanym. W badaniach szczególną uwagę zwrócono na jej wodoodporność.Indywidualne projektowanie składu spoiwa pozwala na precyzyjne dostosowanie jegooddziaływania do warunków terenowych oraz wymaganych parametrów recyklowanejpodbudowy. Projekt recyklowanej podbudowy z asfaltem spienionym symulował procesrecyklingu głębokiego na zimno. Zastosowane składniki mineralne tj. destrukt asfaltowy,kruszywo 0/31,5 mm oraz kruszywo doziarniające 0/4 stanowiły materiał odpadowyz istniejącej konstrukcji. W składzie recyklowanej podbudowy zastosowano spoiwa drogowe, które wytworzono w warunkach laboratoryjnych z wymieszania trzech bazowychskładników. Udział procentowy poszczególnych spoiw drogowych określono zgodnychz planem eksperymentu sympleksowo-centroidowego. Na podstawie uzyskanych wynikówbadań stwierdzono różnorodny wpływ analizowanych składników spoiw drogowych nawłaściwości mechaniczne oraz wodoodporność recyklowanej podbudowy. W oparciuo zastosowany plan eksperymentu możliwe było określenie składu spoiwa drogowego, którezapewni uzyskanie recyklowanej podbudowy odpornej na działanie wody

    Characteristics of the complex modulus of recycled cold mix with foamed bitumen and recycled concrete aggregate

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    This article presents research on recycled cold mix with foamed bitumen (MCAS) containing recycled concrete aggregate. The primary concept driving this research was to determine if recycled concrete aggregate (RC) could be used as a substitute for reclaimed asphalt pavement (RAP). Recycled concrete aggregate was used in the MCAS mix in amounts ranging from 20%, 60% and 80%. The reference mix was the MCAS mix containing 50% reclaimed asphalt pavement (RAP) and virgin aggregate. Identical 0/31.5-mm continuously graded dolomite virgin aggregate was used in all mixes. 2.5% foamed bitumen (FB) and 2.0% CEM I 42.5R Portland cement (PC) were used to increase the cohesion of the mineral mix. Foamed bitumen was produced from 50/70 penetration paving bitumen. The behaviour of the recycled base course was tested in the range of cyclic sinusoidal strain with amplitude εo = 25–50 με. The tests were carried out in the (-7°C, 5°C, 13°C, 25°C, 40°C) temperature and (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz) loading time range. The complex modulus was tested in a direct tension-compression test on cylindrical samples (DTC-CY) in accordance with EN 12697-26. The results of the tests were used to assess the complex modulus (E*), phase angle (φ) and complex modulus components (E1) and (E2).Tests of the mixes indicate that recycled concrete aggregate can be used in recycled cold mixes in amounts of up to 80%. Increasing the amount of recycled concrete aggregate does not cause excessive stiffness of the recycled mix in comparison with the reference mix. The tests did not demonstrate a significant difference in terms of the phase angle (φ), which indicates a similar content of the viscous part and elastic part in the obtained complex modulus for the reference mix (RAP + MCAS) and the mix containing recycled concrete aggregate (RC + MCAS)

    The Influence of a Polymer Powder on the Properties of a Cold-Recycled Mixture with Foamed Bitumen

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    The paper investigates the influence of redispersible polymer powder (RPP) on the physical and mechanical properties of a cold-recycled mixture with foamed bitumen (CRM-FB). Four types of RPP with a varied chemical base were used: VA-VeoVA, VA-VeoVa-Ac, EVA and VA/VV/E/Ac. The polymer powder-modified cold recycled mixture with foamed bitumen, (P)CRM-FB, was composed of 45.8% reclaimed asphalt pavement (RAP), 45.8% natural aggregate (VA), 3.0% Portland cement CEM I 42,5R, 3.0% foamed bitumen 50/70 and 3.0% RPP, all dosed by weight. The reference mixture, (R)CRM-FB, served as a reference point for comparison. It was found that RPP improved the workability of the CRM-FB mixture. This results in a reduced number of compaction cycles and lower energy needed to obtain the air void content as in the reference mixture. In addition, the RPP modifier markedly increased the CRM-FB mixture cohesion (ITSDRY) and strength, by approximately 40–70%, depending on the RPP used. These findings are particularly important for CRM-FB mixtures designed for road bases. The present investigations confirmed the improvement of the CRM-FB mixture parameters after the modification with RPP, regardless of the powder type used

    Effects of Portland Cement and Polymer Powder on the Properties of Cement-Bound Road Base Mixtures

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    This article presents the test results for the physical and mechanical properties and fracture toughness of polymer-modified hydraulically-bound mixtures (HBM) produced with Portland cement for road base layers. The modifier used was a redispersible polymer powder (RPP) based on a vinyl ethylene acetate (EVA) copolymer obtained by spray drying. A three-level full factorial design with two factors was applied to determine the contents of Portland cement and polymer powder in the cement-bound mixture (CBM). Both Portland cement and polymer powder were added at three levels: 0%, 2%, and 4%. The assessment included basic physical properties (water absorption, density, and bulk density) and mechanical properties (stiffness modulus, axial compressive strength, and indirect tensile strength) of the CBM. Particular attention was paid to the assessment of fracture toughness in the semi-circular bending test. The results of the research show that polymer powder positively influenced the mechanical properties of CBM by improving its cohesion while maintaining its stiffness. Another benefit coming from the use of polymer powder was the CBM’s increased resistance to cracking, which is the desired characteristic from the perspective of pavement durability

    Study of incident rate of sports injuries and physiotherapy care assessment among students of the Stanislaw Marusarz Sports High School in Zakopane.

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    Wprowadzenie. Sport, a przede wszystkim sport wyczynowy, predysponuje do zwiększonego ryzyka wystąpienia urazu. Pomimo starań wkładanych w działania profilaktyczne sztabów szkoleniowych, uraz jest nieodłączną częścią uprawiania sportu. Specyfika sportów zimowych sprawia, że sportowcy uprawiający te dyscypliny są szczególnie narażeni na wystąpienia urazów w trakcie trwania kariery sportowej.Cel pracy. Celem pracy jest scharakteryzowanie zjawiska urazowości, częstości jego występowania oraz dostępności usług fizjoterapeutycznych wśród zawodników uprawiających sporty zimowe na wysokim, międzynarodowym poziomie, na podstawie badań uczniów Liceum Ogólnokształcącego Mistrzostwa Sportowego w Zakopanem im. Stanisława Marusarza.Materiał i metoda. Badania przeprowadzone zostały w maju 2014 roku wśród 46 uczniów Liceum Ogólnokształcącego Mistrzostwa Sportowego w Zakopanem im. Stanisława Marusarza. Narzędziem badawczym był kwestionariusz autorski składający się z 31 pytań. Wyniki. 54,3% sportowców doznało w swojej karierze zawodniczej przynajmniej jednorazowo urazu, który wyeliminował ich z treningu na okres dłuższy niż jeden tydzień. Wśród doznanych urazów znalazły się m.in. złamania (28% badanych), skręcenia (16% badanych), stłuczenia (16% badanych) oraz zwichnięcia (8% badanych). Z pomocy fizjoterapeuty skorzystało 63% zawodników. Podczas procesu szkoleniowego większość, bo około 87% sportowców korzysta z zabiegów odnowy biologicznej. Sportowcy ci korzystają najczęściej z masaży (82% badanych), z sauny (62,5% badanych) rzadziej z kąpieli leczniczych (47,5% badanych).Wnioski. Wykazana wysoka urazowość w badanej grupie wskazuje na powagę problemu występowania urazów wśród sportowców. Odpowiednie przygotowanie motoryczne oraz regularna opieka fizjoterapeutyczna może zminimalizować ilość doznawanych obrażeń.Introduction. Sport, especially professional sports, predisposes to increased risk of injury. Despite the efforts inserted in preventive action, injury is inherent part of sport. Specificity of winter sports makes athletes of these disciplines, particularly vulnerable to the occurrence of injuries during their career. Aim of the study. Aim of this study is to characterize the phenomenon of traumas, frequency rate and availability of physiotherapy services among competitors of winter sports at a high international level, based on the research among students of the Stanislaw Marusarz Sports High School in Zakopane. Material and methods. The study was carried out in May 2014 year among 46 students of the Stanislaw Marusarz Sports High School in Zakopane. The research tool was a questionnaire comprised of 31 questions. Results. 54.3% of the athletes suffered in their career at least one injury, which eliminated them from training for a period longer than one week. Among the injuries suffered were, fractures (28%), sprains (16% of respondents), contusions (16% of respondents) and dislocation (8% of respondents). 63% of athletes declares that they benefited from aid of a physiotherapist. During the training process the majority 87% of the athletes use of wellness treatments. Athletes use most often massage (82% of respondents), a sauna (62.5% of respondents) and medicinal bath (47.5% of respondents). Conclusions. Demonstrated high traumatism in the study group indicates the seriousness of the problem which are injuries among athletes. Proper preparation of the motor skills and the regular physiotherapy care can minimize the amount and severity of injuries

    Characteristics of the complex modulus of recycled cold mix with foamed bitumen and recycled concrete aggregate

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    This article presents research on recycled cold mix with foamed bitumen (MCAS) containing recycled concrete aggregate. The primary concept driving this research was to determine if recycled concrete aggregate (RC) could be used as a substitute for reclaimed asphalt pavement (RAP). Recycled concrete aggregate was used in the MCAS mix in amounts ranging from 20%, 60% and 80%. The reference mix was the MCAS mix containing 50% reclaimed asphalt pavement (RAP) and virgin aggregate. Identical 0/31.5-mm continuously graded dolomite virgin aggregate was used in all mixes. 2.5% foamed bitumen (FB) and 2.0% CEM I 42.5R Portland cement (PC) were used to increase the cohesion of the mineral mix. Foamed bitumen was produced from 50/70 penetration paving bitumen. The behaviour of the recycled base course was tested in the range of cyclic sinusoidal strain with amplitude εo = 25–50 με. The tests were carried out in the (-7°C, 5°C, 13°C, 25°C, 40°C) temperature and (0.1 Hz, 0.3 Hz, 1 Hz, 3 Hz, 10 Hz, 20 Hz) loading time range. The complex modulus was tested in a direct tension-compression test on cylindrical samples (DTC-CY) in accordance with EN 12697-26. The results of the tests were used to assess the complex modulus (E*), phase angle (φ) and complex modulus components (E1) and (E2).Tests of the mixes indicate that recycled concrete aggregate can be used in recycled cold mixes in amounts of up to 80%. Increasing the amount of recycled concrete aggregate does not cause excessive stiffness of the recycled mix in comparison with the reference mix. The tests did not demonstrate a significant difference in terms of the phase angle (φ), which indicates a similar content of the viscous part and elastic part in the obtained complex modulus for the reference mix (RAP + MCAS) and the mix containing recycled concrete aggregate (RC + MCAS)

    Bitumen Foaming Optimisation Process on the Basis of Rheological Properties

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    This article discusses the results of bitumen foam properties optimisation with respect to three factors: air pressure, bitumen temperature and amount of water. The test materials were unmodified bitumen 50/70 and bitumen 50/70 modified with 2.5% synthetic wax. The experiment was designed according to the 3(3−1) fractional factorial design. The distribution of parameters of bitumen foam were measured with the authors’ original apparatus using a laser beam. This measurement method increased the accuracy of maximum expansion ratio (ER) and half-life (HL) estimation. Based on HL and ER results, it was found that the foaming process increased bitumen stiffness due to the dynamic ageing of the bitumen. The experimental design allows more effective control over the properties of foamed bitumen with respect to its intended use. The presence of synthetic wax extended the half-life of the bitumen foam

    Prognozowanie modułu sztywności względem podstawowych cech fizycznych i mechanicznych podbudowy recyklowanej z asfaltem spienionym i emulsją asfaltową

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    The paper’s objective was to present the results of predicting the stiffness modulus of a recycled mix containing a blended road binder with foamed bitumen and emulsified bitumen. The Sm (acc. to IT-CY) indirect tensile test was used at temperatures of -10°C, +5°C, +13°C and +25°C. Prediction of the stiffness modulus accounted for the effect of temperature, the type of road binders, the sampling location and the type of technology selected. All effects, except temperature, were included in the model by entangling their effects through recycled base course physical and mechanical characteristics, such as indirect tensile strength, compressive strength, creep rate, air void content and moisture resistance. As a result, it was possible to determine a regression model based on multiple regression with a coefficient of determination R2 = 0.78. Temperature and compressive strength were found to have the strongest effect on the variability of stiffness modulus. However, indirect tensile strength also significantly affected the Sm characteristic. In addition, FB-RCM (foamed bitumen) recycled mixtures proved to be more favourable than EB-RCM (emulsified bitumen) mixtures as they exhibited a lower deformation rate while retaining limited stiffness.Mieszanki recyklowane są powszechnie wykorzystywanym materiałem do budowy podbudowy zasadniczej i pomocniczej zarówno w przebudowach jak i nowych konstrukcji drogowych. Mogą one być wykonywane w technologii asfaltu spienionego jak i również emulsji asfaltowych. Należy pamiętać, że zastosowanie materiału odpadowego lub pochodzącego z recyklingu kwalifikuje tę technologię jako rozwiązanie proekologiczne. Aplikacja spoiwa drogowego zawierającego 100% cementu jest najczęściej wykorzystywanym sposobem podnoszenia stopnia kohezji mieszanek recyklowanych. Nie mniej jednak brak poprawnie wykonanego procesu optymalizacji ilości cementu może doprowadzić do nadmiernego przesztywnienia mieszanki recyklowanej i pojawieniem się spękań. Pomimo wielu korzyści, jakie wynikają ze stosowania technologii recyklingu wciąż napotykane się ograniczenia w jej stosowaniu i popularyzacji. Główną przyczyną jest brak kompleksowej wiedzy z zakresu struktury wewnętrznej mieszanek recyklowanych oraz panujących w niej efektów reologicznych, co objawia się częstymi awariami dróg o dużym natężeniu ruchu, które zostały wykonane na podbudowie z mieszanki recyklowanej [13, 43]. W związku z tym była to jedna z przyczyn ograniczenia stosowania tej technologii w Polsce dla ruchu o natężenia pojazdów powyżej ESAL100 kN >7,3 mln osi. W związku z tym autorzy podjęli się zadania związanego z możliwością prognozowania zmiany modułu sztywności mieszanki recyklowanej, rozrzedzając swoje działania o efekty związane z: technologią recyklingu, rodzajem spoiwa oraz zjawiskami jakie mogą wystąpić w czasie realizacji odcinka doświadczalnego. W artykule zostały przedstawione rezultaty prognozowania modułu sztywności mieszanki recyklowanej zawierającej mieszane spoiwo drogowe w technologii asfaltu spienionego oraz emulsji asfaltowej. Badanie modułu sztywności wykonano metodą pośredniego rozciągania IT-CY. Moduł sztywności oznaczono w temperaturach –10°C, +5°C, +13°C oraz +25°C. Prognozowanie modułu sztywności uwzględniało efekt temperatury, rodzaj spoiw drogowego, miejsce poboru próbek oraz rodzaj technologii. Wszystkie efekty, oprócz temperatury, zostały uwzględnione w modelu poprzez uwikłanie ich oddziaływania za pomocą cech fizycznych i mechanicznych recyklowanej podbudowy takich jak: wytrzymałość na pośrednie rozciąganie, wytrzymałość na ściskanie, szybkość pełzania, zawartość wolnej przestrzeni oraz odporność na oddziaływanie wody

    The Influence of Recycled Materials on Cold Mix with Foamed Bitumen Properties

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    The utilization of recycled materials is an important issue in the context of environmental protection. The large amounts of recycled material recovered from the demolition of asphalt road structures indicate the need to find new ways of utilizing them. In the case of road renovation projects, large amounts of recycled materials are, in most cases, recovered in the form of reclaimed asphalt pavement (RAP), reclaimed concrete (RC) and recycled aggregate (RA). To focus on the effects of the use of recovered materials (RAP, RC and RA), the same composition was used for all of the analyzed mixtures in terms of foamed bitumen (FB) and Portland cement (CEM) content. The scope of laboratory tests included the specification of the following parameters: the amount of air void content Vm, the determination of axial compression strength at +25 °C, indirect tensile strength (ITS) at +25 °C, water resistance, TSR, water and frost resistance, WRW+M stiffness modulus (IT-CY) at 13 °C, dynamic dynamicmodulus. The plan of the experiment assumed addition recycled material in quantities between 20% and 80% in increments of 20%. The obtained results indicate that both the type and quantity of recycled material significantly affect the properties of the cold-recycled mixture with foamed bitumen. Using reclaimed asphalt pavement and recycled cement concrete guarantees high levels of stiffness in the recycled mixture. Howeverin the case of recycled aggregate, the authors did not observe any visible changes in the dynamicdynamic modulus, irrespective of the loading conditions. It was also indicated that it is necessary to reduce the quantity of reclaimed asphalt pavement in the composition of the FB-RCM mix to maintain the required air void content

    Composition Optimisation of Selected Waste Polymer-Modified Bitumen

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    Waste plastomer disposal is currently a major challenge facing modern economies. This article reports on a study and analysis regarding the implementation of plastomers into bitumen, with a special focus on the influence of mixing process factors. Two plastomers were selected for analysis, PP and PET, and two bitumen types, 20/30 and 70/100, were modified. Determination of the basic characteristics, such as penetration, softening temperature, cohesion energy, and Fraass temperature, was complemented with advanced multiple-stress creep recovery (MSCR) rheological testing. The entire experimental process followed the Plackett–Burman design. Rheological effects of modified bitumen were evaluated using the generalized Maxwell model. Microstructural analysis with epi-fluorescence microscopy showed the ability of plastomer-modified bitumen to obtain a fine-grained structure with a particle size of <10 μm. In addition, creep susceptibility (Jnr) was found to be statistically significantly dependent on the polymer type and particle size, rotational speed, and bitumen type. In turn, the particle dispersion structure in the bitumen matrix significantly depended on the rotational speed, plastomer particle size, and mixing temperature. Ultimately, the process of bitumen 70/100 modification was optimized. It was demonstrated, following the experimental design, that by using fine-grained PP for a temperature of 160 °C, rotational speed of about 6300 rpm and time of 105 min, it is possible to obtain modified bitumen with rheological properties very similar to those of modified bitumen PmB 45/80-55
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