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Vodní režim půd rekultivovaných a nerekultivovaných výsypek po těžbě uhlí / Soil water regime of reclaimed and unreclaimed post mining heapsCejpek, Jiří January 2018 (has links)
This PhD thesis compares the water regime of reclaimed and unreclaimed spoil heaps after brown coal mining, with special regard to the development of hydrological properties of soils, which are determinant for the movement and retention of water in the soil. The basic influence on the supply of soil water has the technology of pouring the spoil heaps and aging, which co-regulates the development of vegetation. During the development of soil's spoil heaps increases field water capacity and water retention, but also increases the wilting point. These changes are related to the accumulation of organic matter in the soil and the degradation of claystones to particle size of physical clay. The development of the ability of the spoil heaps soils to bind water is greater in reclaimed areas, where the upper organomineral horizon develops more rapidly, but there is also a wilting point and water consumption. On unreclaimed area, the soil substrate develops more slowly. Overall, the differences in water regime between reclaimed and unreclaimed areas are small.
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Použití R-materiálu do asfaltových směsí typu asfaltový koberec mastixový / Usage of reclaimed asphalt pavement in stone mastic asphaltCoufalíková, Iva January 2019 (has links)
The dissertation deals with the possibilities of adding recycled asphalt pavement (RAP) to the stone mastic asphalt (SMA), which is increasingly being promoted due to its good resistance to permanent deformations and high traffic load. Thanks to the use of high-quality input materials in production, this is a valuable material source. The theoretical part describes composition of SMA mixture and problems of pavement recycling. The practical part deals with SMA 11S laboratory designs with RAP ratio of 0 to 50%. Based on these suggestions, a trial section with 17 variants was placed, which varied with the content and quality of the RAP and the used additives. All variants have been subjected to functional testing not only on mixtures but also on recovered binders. The results obtained during the dissertation were used to build a certified methodology named "Methodology of application RAP to Stone Mastic Asphalt." In conclusion, the results of the dissertation are summarized.
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Možnosti mísení pojiv typu PMB RC s pojivem z R-materiálu / Possibility of mixing PMB RC type binders with reclaimed binder from RAPTrnka, Lukáš Unknown Date (has links)
The diploma thesis deals with the possibility of mixing binders of the PMB RC type with a binder made of reclaimed ashalt. lists the types of asphalt binders, its production and modification are in the teoretical part. There is explained the principle of rejuvenators function, types of rejuvenators. The procedures for performing tests on asphalt binders: recovery of asphalt binder, needle penetration, softening point (ring and ball method), reversible ductility, breaking point (according to Fraass) and DSR. Individual tests are evaluated and asphalt mixtures are compared in the practical part of asphalt binder. The diploma thesis deals with the possibility of mixing binders of the PMB RC type with a binder made of reclaimed ashalt. lists the types of asphalt binders, its production and modification are in the teoretical part. There is explained the principle of rejuvenators function, types of rejuvenators. The procedures for performing tests on asphalt binders: recovery of asphalt binder, needle penetration, softening point (ring and ball method), reversible ductility, breaking point (according to Fraass) and DSR. Individual tests are evaluated and asphalt mixtures are compared in the practical part of asphalt binder.
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Využití polymerem modifikovaných asfaltů a oživovacích přísad v asfaltových směsích / Usage of polymer modified bitumens and rejuvenators in asphalt mixturesMaláník, Stanislav Unknown Date (has links)
Diploma thesis deals with the influence of various dosing of Reclaimed asphalt pavement (RAP) using modified bitumen on the properties of asphalt concrete (ACO 11+) of cemented by polymer modified bitumen, while a rejuvenating agents are added into asphalt mixtures. The theoretical part of the thesis summarizes the basic knowledge of pavement recycling, polymer modified bitumens and their reuse in asphalt mixtures. The practical part deals with laboratory tests of ACO 11+ mixtures with the RAP proportion of 0 % to 50 %. The asphalt mixtures compared are evaluated by means of the Thermal Stress Restrained Specimen Test (TSRST) and Stiffness test. The results obtained within the diploma thesis can approximate the issue of recycling of asphalt mixtures with polymer modified bitumens.
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Evaluation of Laboratory Durability Tests for Stabilized Aggregate Base MaterialsRoper, Matthew B. 19 May 2007 (has links) (PDF)
The Portland Cement Association commissioned a research project at Brigham Young University to compare selected laboratory durability tests available for assessing stabilized aggregate base materials. The laboratory research associated with this project involved two granular base materials, three stabilizers at three concentration levels each, and three durability tests in a full-factorial experimental design. The granular base materials consisted of an aggregate-reclaimed asphalt pavement blend obtained from Interstate 84 (I-84) and a crushed limestone obtained from U.S. Highway 91 (US-91), while the three stabilizer types included Class C fly ash, lime-fly ash, and Type I/II Portland cement. Specimens were tested for durability using the freeze-thaw test, the vacuum saturation test, and the tube suction test. Analyses of the test results indicated that the unconfined compressive strength (UCS) and retained UCS were higher for specimens tested in freeze-thaw cycling than the corresponding values associated with vacuum saturation testing. This observation suggests that the vacuum saturation test is more severe than the freeze-thaw test for materials similar to those evaluated in this research. The analyses also indicated that the I-84 material retained more strength during freeze-thaw cycling and vacuum saturation and exhibited lower final dielectric values during tube suction testing than the US-91 material. Although the I-84 material performed better than the US-91 material, the I-84 material required higher stabilizer concentrations to reach the target 7-day UCS values specified in this research. After freeze-thaw testing, the Class C fly-treated specimens were significantly stronger than both lime-fly ash- and cement-treated specimens. In the vacuum saturation test, none of the three stabilizer types were significantly different from each other with respect to either UCS or retained UCS. Dielectric values measured during tube suction testing were lowest for cement-treated specimens, indicating that cement performed better than other stabilizers in reducing the moisture/frost susceptibility of the treated materials. The results also show that, as the stabilizer concentration level increased from low to high, specimens performed better in nearly all cases. A strong correlation was identified between UCS after the freeze-thaw test and UCS after the vacuum saturation test, while very weak correlations were observed between the final dielectric value after tube suction testing and all other response variables. Differences in variability between test results were determined to be statistically insignificant. Engineers interested in specifying a comparatively severe laboratory durability test should consider vacuum saturation testing for specimens treated with stabilizers similar to those evaluated in this research. The vacuum saturation test is superior to both the freeze-thaw and tube suction tests because of the shorter duration and lack of a need for daily specimen monitoring. Although the Class C fly ash used in this research performed well, further investigation of various sources of Class C fly ash is recommended because of the variability inherent in that material. Similar research should be performed on subgrade soils, which are also routinely stabilized in pavement construction. Research related to long-term field performance of stabilized materials should be conducted to develop appropriate thresholds for laboratory UCS values in conjunction with vacuum saturation testing.
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Variability in Construction of Cement-Treated Base Layers: Probabilistic Analysis of Pavement Life Using Mechanistic-Empirical ApproachRogers, Tyler J. 23 November 2009 (has links) (PDF)
The primary objective of this research was to quantify the improvement in service life of a flexible pavement constructed using full-depth reclamation (FDR) in conjunction with cement stabilization when specified reductions in the spatial variability of specific construction-related parameters are achieved. This study analyzed pavement data obtained through field and laboratory testing of a reconstruction project in northern Utah. Data analyses included multivariate regression, Monte Carlo simulation, and mechanistic-empirical analyses of a model pavement structure. The results of the research show a steadily increasing trend in 28-day unconfined compressive strength of the cement-treated base (CTB) layer with increasing reductions in variability for cement content, moisture content, and reclaimed asphalt pavement (RAP) content across each of five different reliability levels. The most significant increases in CTB strength occurred with reductions in the standard deviations of moisture content and RAP content. Decreasing the variability of cement content did not provide significant additional strength to the CTB layer. Therefore, when involved on FDR projects, members of the pavement industry should focus energy on reducing the variability of both moisture content and RAP content, which both significantly impact pavement life, to achieve high-quality, long-lasting pavements.
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Factors Affecting the Strength of Road Base Stabilized with Cement Slurry or Dry Cement in Conjunction with Full-Depth ReclamationDixon, Paul A. 19 April 2011 (has links) (PDF)
Full-depth reclamation (FDR) in conjunction with cement stabilization is an established practice for rehabilitating deteriorating asphalt roads. Conventionally, FDR uses dry cement powder applied with a pneumatic spreader, creating undesirable fugitive cement dust. The cement dust poses a nuisance and, when inhaled, a health threat. Consequently, FDR in conjunction with conventional cement stabilization cannot generally be used in urban areas. To solve the problem of fugitive cement dust, the use of cement slurry, prepared by combining cement powder and water, has been proposed to allow cement stabilization to be utilized in urban areas. However, using cement slurry introduces several factors not associated with using dry cement that may affect road base strength, dry density (DD), and moisture content (MC). The objectives of this research were to 1) identify construction-related factors that influence the strength of road base treated with cement slurry in conjunction with FDR and quantify the effects of these factors and 2) compare the strength of road base treated with cement slurry with that of road base treated with dry cement. To achieve the research objectives, road base taken from an FDR project was subjected to extensive full-factorial laboratory testing. The 7-day unconfined compressive strength (UCS), DD, and MC were measured as dependent variables, while independent variables included cement content; slurry water batching temperature; cement slurry aging temperature; cement slurry aging time; presence of a set-retarding, water-reducing admixture; and aggregate-slurry mixing time. This research suggests that, when road base is stabilized with cement slurry in conjunction with FDR, the slurry water batching temperature; haul time; environmental temperature; and presence of a set-retarding, water-reducing admixture will not significantly affect the strength of CTB, provided that those factors fall within the limits explored in this research and are applied to a road base with similar properties. Cement content and cement-aggregate mixing time are positively correlated with the strength of CTB regardless of cement form. Additionally, using cement slurry will result in slightly lower strength values than using dry cement.
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Temporal and Spatial Variability in Base Materials Treated with Asphalt EmulsionQuick, Tyler James 17 March 2011 (has links) (PDF)
The first objective of this research was to investigate temporal trends in the mechanical properties of base materials stabilized with asphalt emulsion and to assess the rate at which emulsion-treated base (ETB) design properties are achieved. The second objective of this research was to identify construction and environmental factors most correlated to specific mechanical properties of ETB layers and to determine which construction factors exhibit the greatest variability. Additional statistical analysis was performed to determine if significant differences existed between different test sections on a given project. In this research, three experimental sections were established along a pavement reconstruction project near Saratoga Springs, Utah. Field tests were performed to assess the structural properties of the ETB immediately following construction and at 2, 3, 7, and 14 days; 4 months; and 1 year. Measured values were plotted against time to determine trends in ETB strength development. Several statistical analyses were then performed on the collected data. Modulus values were consistently low in all three sections during the first two weeks of testing, increased dramatically by 4 months, and then decreased considerably by 1 year. During the first two weeks following construction, the average ETB structural coefficient was 0.04. Only two of the three sections reached the design structural coefficient of 0.25, which occurred after approximately 3 months; however, the average structural coefficient measured for all three sections after 1 year of curing, which included a winter, was only 47 percent of the design strength. The results of this research show that, while pavement capacity is sufficient at 4 months, it is severely reduced during the first two weeks and at 1 year. Trafficking under these reduced capacities is not recommended. Statistical analysis showed that gradation, binder change during emulsion treatment, and moisture content have the most significant impact on ETB structural properties. Gradation and binder change during emulsion treatment also exhibited significant variability; tighter specifications on material gradations and improved uniformity in emulsion distribution should therefore be considered. Because of the negative impacts of moisture on ETB strength development, construction should not be performed in conditions of excess moisture.
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Calcareous Compacted Mine Soil in Southeast Ohio: A Prairie Grass HabitatThorne, Mark Ervin 15 January 2010 (has links)
No description available.
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Återvunnet avloppsvatten, dagvatten eller dricksvatten för bevattning? : En multikriterieanalys över alternativa vattenkällor för bevattning hos Malmö Burlöv Golfklubb / Recycled waste water, stormwater or drinking water for irrigation? : A multi criteria analysis of alternative irrigation sources at Malmö Burlöv Golf clubVärnqvist, Sara January 2021 (has links)
Förändrade förhållanden följer de allt mer påtagliga klimatförändringarna. Stora delar av samhällen är beroende av tillgång på rent vatten vilket tvingar länder till klimatanpassning. I Sverige lider många regioner av vattenbrist medan andra har tillgång en större mängd vatten. I, bland andra, Skåne väntas stora temperaturhöjningar vilket medför mer avdunstning och torrare förutsättningar. Klimatförändringarna förväntas öka trycket samhället ställer på de tillgängliga vattenresurserna. Malmö Burlöv Golfklubb (Malmö Burlöv Gk) belägen i västra Skåne är en av många som kommer påverkas av de torrare förutsättningar samt ökade mängder av näringsämnen som göder vattendragen. Deras nuvarande vattenkälla för bevattning, Sege å, saknar tillfredsställande vattenkvalitet och därmed söker golfklubben efter andra alternativ. Syftet med examensarbetet är att identifiera och jämföra lämpligheten för tre alternativa vattenkällor för bevattning av golfbanan hos Malmö Burlöv Golfklubb jämfört en referens. Lämpligheten att användas som källa för bevattning utreds genom multikriterieanalys (MKA), med verktyget Water Investments for Sustainability Enhancement and Reliability (WISER). Via extern litteratur identifierades tre alternativa bevattningssystem samt ett referenssystem. Systemen vilka inkluderades i analysen var återvunnet avloppsvatten, dagvatten, dricksvatten samt bevattning med grundvatten (referens). Litteraturen över tidigare forskning visar att systemen används runt om i världen med olika framgång. I länder såsom Australien, USA och delar av mellanöstern används återvunnet avloppsvatten för bevattning av vindruvor vilket avlastar samhällets vattenresurser. I Indien har höga koncentrationer av olika skadliga ämnen uppmätts i områden där avloppsvatten, vilket endast genomgått en enkel reningsprocess alternativt ingen rening, används för bevattning. Studien betonar vikten av avancerad rening av det inkommande vattnet innan det används. Ett flertal studier visar att en alternativ bevattning (icke-dricksvatten) ofta anses mer acceptabelt bland allmänheten. I en del av Kanadas parkområden används dagvatten för bevattning vilket visat ha en positiv effekt på människors uppfattning kring användande av alternativa vattenkällor. Studier visar även att användarna kräver en viss distans mellan vatten, från den alternativa vattenkällan, och individ. Alternativa system har därför implementerats för ändamål där exponeringen är låg, till exempel vid bevattning, vilket har visats vara gynnsamt. I examensarbetet jämfördes de tre identifierade alternativen med referenssystemet utifrån 22 kriterier vilka inkluderar teknisk, social, ekonomisk samt miljömässig analys. Samtliga kriterier inkluderade i analysen är presenterade av verktyget WISER. Utifrån tidigare studier, rapporter samt antaganden gjordes en bedömning av alternativens prestation för varje enskilt kriterium. Resultatet som erhölls, via viktning som genomförts av kund- och marknadsansvarig på Malmö Burlöv Gk, visar att systemet som brukar dagvatten för bevattning kan anses mest lämpligt utifrån förutsättningarna för den studerade golfklubben. Systemet är det enda som erhåller ett positivt slutligt index och erhåller endast lägsta poäng för två av 22 kriterier medan det erhåller poäng vilken indikerar en likgiltig, tillfredsställande samt mycket tillfredsställande prestation för 19 av 22 kriterier. Utifrån resultatet ges därför rekommendationen att dagvatten för bevattning är det mest lämpliga alternativet för Malmö Burlöv Gk men att justeringar av systemet behöver genomföras innan implementering. Känslighetsanalysen visar dock att resultatet begränsas av golfklubbens ekonomiska tillgångar vilket innebär att systemet som brukar återvunnet avloppsvatten kan rekommenderas för implementering om golfklubben kan beviljas bidrag. Övriga system kan inte uteslutas vara lämpliga alternativ då en MKA och WISER endast ger en indikation vilket system som är att föredra relativt de andra alternativen och inte hur alternativen presterar jämfört riktlinjer, standarder och regler. / Climate change has become a world known phenomenon. Parts of societies are dependent on the availability of clean water which puts a greater pressure on nations to adapt to the changing climate. Many regions in Sweden, Scania amongst others, is affected by water scarcity and therefore, societies are predicted to put a greater pressure on water sources used throughout the communities. A golf course located in western part of Scania, Malmö Burlöv Golf club (Malmö Burlöv Gk), will be one of many that will be impacted by the droughts and the increase of fertilizers in watercourses. Their current water source, the water course Sege å, used for irrigation has an inadequate water quality which has caused Malmö Burlöv Gk to seek other options. The aim of the master thesis is therefore to identify and compare the suitability for irrigation purpose of three alternative water sources at Malmö Burlöv Gk. The comparison was made in Water Investments for Sustainability Enhancement and Reliability (WISER) which is a new multi-criteria analysis (MCA) tool. Three alternatives were identified by reading literature and previous studies. The three systems included in the analysis were recycled wastewater from Sjölunda wastewater treatment plant, stormwater and drinking water. Previous studies indicated that similar systems, for example recycled wastewater, were used in many different parts of the world, with different levels of success. In Australia, the US, and parts of the middle east the use of wastewater for irrigation of grapes allowed clean water to be reallocated for other purposes. However, in India, where untreated wastewater was most used high concentrations of harmful substances could be found in the crops and ground where the water was used. In the master thesis the three alternatives were compared to a reference system, irrigation with groundwater, based on 22 criteria which were chosen from WISER. The criteria were based on social, technical, environmental, and economic aspects. Each criterion received a grading based on the performance of the alternative, which was based on previous studies, reports, and assumptions. The results show that the stormwater system is the most suitable based on the conditions at the site as it obtains a positive score (or neutral) for 19 of the 22 analyzed criteria. In addition, the sensitivity analysis show that the results are heavily dependent on the golf clubs’ economical assets. Therefore, a recommendation to implement stormwater system with a few adjustments or, if grants can be found, the system for recycled wastewater is made. Furthermore, the choice of methodology (MCA) will have an impact on the results where for example, scoring will affect the relative grading. In addition, an MCA and WISER can only decide which alternative will be considered more suitable compared to the rest of the alternatives and not if it is applicable at the site. The performance of the alternatives relative existing guidelines and laws must be investigated before implementing the chosen system. It is therefore important to recognize the rest of the alternatives as suitable before proven otherwise.
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