Adierazle eta indizeen analisia eta tratamendua errepideen bide-zoruen birgaitzeari burusko erabakiak hartzeko jasangarritasunaren irizpideen arabera : aplikazioa Bizkaiko errepide-sarea

797 p.Due to the competition of funding among different sectors of the economy and society, Pavement Management Systems (PMS) have become necessary for road agencies to design more cost-effective and longer lasting pavements and to better allocate available funds. Within the PMS, the performance models are a key factor, as they are able to predict the future condition of the pavements.The Regional Government of Biscay (RGB) manages and is responsible of almost the entire interurban road network in the territory of Biscay, making a total of more than 1.300 km under its control. Aiming to efficiently manage its resources, the RGB has developed a PMS, where all the information about roads is stored.The aim of this PhD thesis is to develop performance models for the International Roughness Index (IRI) and the Side-force coefficient to predict the future condition of the road network of Biscay. IRI models are developed for new two-lane roads with flexible and semi-rigid pavements. The proposed models for forecasting skid resistance can be deployed in any type of road, two-lane roads or double carriageway roads and for all the usual materials in surface layers.-----Debido a la competencia por la obtención de fondos de los diferentes sectores de la economía y de la sociedad, los Sistemas de Gestión de Firmes (SGF) se han convertido en necesarios para las administraciones viarias para conseguir unos pavimentos más eficientes con respecto a su coste y con mayor duración y asignar mejor los fondos disponibles en actuaciones. Dentro de los SGF, los modelos de comportamiento son un factor clave, dado que son capaces de predecir el estado futuro de los pavimentos. La Diputación Foral de Bizkaia (DFB) gestiona y es responsable de la mayoría de las carreteras interurbanas que discurren por el territorio histórico de Bizkaia, teniendo bajo su control directo más de 1.300 km de carreteras. Para una más eficiente gestión de sus recursos, la DFB ha desarrollado un SGF, donde se encuentra almacenada toda la información relativa a las carreteras.El objetivo de esta tesis es desarrollar unos modelos de comportamiento para el International Roughness Index (IRI) y el Coeficiente de Rozamiento Transversal (CRT) para predecir el estado futuro de la red viaria de Bizkaia. Los modelos de IRI se desarrollan para nuevas carreteras convencionales de dos carriles con firmes flexibles y semirrígidos. El modelo desarrollado para el CRT puede ser utilizado en cualquier tipo de carretera, convencional o de calzadas separadas y todos los materiales habituales en la capa de rodadura.Ekonomiaren eta gizartearen hainbat sektoreren arteko finantzaketa lortzeko lehia dela eta, Bide-zoruak Kudeatzeko Sistemak (BKS) beharrezko bihurtu dira bide-administraziorako luzeago irauten duten eta kostu eraginkorragoko bide-zoruak diseinatzeko eta dauden funtsak hobeto esleitzeko. BKSen barruan, portaera modeloak oinarrizko faktore bat dira, bide-zoruaren etorkizuneko egoera iragartzeko gai direlako.Bizkaiko Foru Aldundiak (BFA) Bizkaiko lurraldeko hiri arteko ia errepide-sarea osoa kudeatzen du eta horren arduraduna da. Beraz, 1.300 km baino gehiago daude bere kontrolpean. Bere baliabideak hobeto kudeatu nahian, BFAk garatu du BKS bat, non errepideei buruzko datu guztiak biltzen diren.Tesi honen helburua International Roughness Index (IRI) eta zeharkako marruskadura koefizienterako portaera-modeloak garatzea da. IRI modeloak garatu dira errepide konbentzional (bi erreiko errepideak) berrietarako, bide-zoru malgu eta erdi-zurrunekin. Labainketarekiko erresistentziarako proposatutako modeloa edozein errepide motarako erabil daiteke, errepide konbentzionaletan edo galtzada bananduko errepideetan eta normalean erabiltzen diren errodadura geruzako materialerako

IRI performance models for recently constructed low and medium-traffic two lane roads of the province of Biscay

[EN] Reliable pavement prediction models are needed for pavement management systems (PMS), as they are a key component to forecast future conditions of the pavement and to prioritize maintenance, rehabilitation, and reconstruction strategies. The International Roughness Index (IRI) is the most used parameter worldwide for calibrating pavement roughness and measures reasonably the ride comfort perceived by occupants of passenger cars. The Regional Government of Biscay also collects this value on the road network under its control. These surveys are carried out regularly in the XXI century. Several IRI performance models have been proposed by different authors and administrations, varying greatly in their comprehensiveness, the ability to predict performance with accuracy and input data requirements. The aim of this paper is to develop a roughness performance model for Biscay’s roads, based on available IRI data, taking into account heavy traffic volume and the age of pavement. Local characteristics as climate conditions and average rainfall are not considered. IRI performance models have been suggested for regional two lane highways with low and medium heavy traffic constructed in the last 20 years in the province of Biscay, with no treatments during their life. They can be applied for flexible pavements, but no logical coherent results have been concluded for semi-rigid pavementsPérez Acebo, H.; Gonzalo-Orden, H. (2016). IRI performance models for recently constructed low and medium-traffic two lane roads of the province of Biscay. En XII Congreso de ingeniería del transporte. 7, 8 y 9 de Junio, Valencia (España). Editorial Universitat Politècnica de València. 582-597. https://doi.org/10.4995/CIT2016.2015.4108OCS58259

Alternatives for chemical and biochemical lignin valorization: Hot topics from a bibliometric analysis of the research published during the 2000-2016 period

A complete bibliometric analysis of the Scopus database was performed to identify the research trends related to lignin valorization from 2000 to 2016. The results from this analysis revealed an exponentially increasing number of publications and a high relevance of interdisciplinary collaboration. The simultaneous valorization of the three main components of lignocellulosic biomass (cellulose, hemicellulose, and lignin) has been revealed as a key aspect and optimal pretreatment is required for the subsequent lignin valorization. Research covers the determination of the lignin structure, isolation, and characterization; depolymerization by thermal and thermochemical methods; chemical, biochemical and biological conversion of depolymerized lignin; and lignin applications. Most methods for lignin depolymerization are focused on the selective cleavage of the β-O-4 linkage. Although many depolymerization methods have been developed, depolymerization with sodium hydroxide is the dominant process at industrial scale. Oxidative conversion of lignin is the most used method for the chemical lignin upgrading. Lignin uses can be classified according to its structure into lignin-derived aromatic compounds, lignin-derived carbon materials and lignin-derived polymeric materials. There are many advances in all approaches, but lignin-derived polymeric materials appear as a promising option.This research has been financially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through CTQ2014-56820-JIN Project, co-financed by FEDER funds from European Union. R. Abejón would also like to thank the financial support provided by “Becas Iberoamérica Santander Investigación 2016/2017 (Santander Universidades)”

Evaluation of the Radar Speed Cameras and Panels Indicating the Vehicles’ Speed as Traffic Calming Measures (TCM) in Short Length Urban Areas Located along Rural Roads

Traffic calming measures (TCMs) are implemented in urban areas to reduce vehicles’ speed and, generally speaking, results are obtained. However, speed is still a problem in rural roads crossing small villages without a bypass and with short-length urban areas, since drivers do not normally reduce their speed for that short segment. Hence, various TCM can be installed. It is necessary to maintain a calm area in these short segments to improve road safety, especially for pedestrian aiming to cross the road, and to save combustible by avoiding a constant increase-decrease of speed. Four villages were selected to evaluate the efficiency of radar speed cameras and panels indicating vehicle’s speed. Results showed that the presence of radar speed cameras reduces the speed in the direction they can fine, but with a lower effect in the non-fining direction. Additionally, a positive effect was observed in the fining direction in other points, such as pedestrian crossings. Nevertheless, the effect does not last long and speed cameras may be considered as punctual measures. If the TCMs are placed far from the start of the village they are not respected. Hence, it is recommended to place them near the real start of the build-up area. Lastly, it was verified that longer urban areas make overall speed decrease. However, when drivers feel that they are arriving to the end of the urban area, due to the inexistence of buildings, they start speeding up.This research was funded by GIRDER Ingenieros, S.L.P., grant number 2019.0478, by “Erasmus + programme—Call 2016—KA1—Mobility of Staff in higher education—Staff mobility for teaching and training activities”, and by Project No WZ/WB-IIL/1/2020 and it was financially supported by Ministry of Science and Higher Education, Poland

Birziklatutako poliuretano-aparraren erabilera nahaste bituminosoetan

Many substances have been used to modify bitumens with the aim of enhacing their properties and performance, but the most widely used are the polymers. Polyurethane foam is a waste product from themal insulation, which is frequently deposited in landfills. Waste polyurethane foam was selected as a possible bitumen modifier in bitumens to produce two differente bituminous mixes: hot mix asphalts with a B 50/70 bitumen and mastic asphalt with B 35/50 bitumen. Different quantities of polymer were added to the bitumens, from 1 % to 5 % in weight of the bitumen. In both bitumens it was shown that 5% or more of polymer made samples became rough and with low workability and, hence, they were discarded. Specimens of both bituminous materials were produced with 4% of polymer. The Marshall test showed that modified hot mix asphalt obtained improvements in stability and a lower deformation when compared to non-modified mixtures. Similarly, the modifed mastic asphalts showed lower identation values than non-modified samples, being able to be employed in road with heavy traffic. Consequently, the waste polyurethane foam resulted in a promising bitumen modifier that enhances bitumen properties.; Sustantzia asko erabili dira betuna eraldatzeko haien propietateak eta errendimendua hobetzeko helburuarekin, baina gehien erabiltzen direnak polimeroak dira. Poliuretano-aparra isolatze termikotik sortzen den hondakin-produktu bat da, normalean zabortegietan amaitzen dena. Hondakin poliuretano-aparra betun eraldatzaile gisa aukeratu zen betunak eraldatzeko bi nahaste bituminoso ezberdinak ekoizteko: beroan egindako nahastea B 50/70 motako betunarekin eta mastika bituminosoa B 35/50 motako betunarekin. Polimerozko (poliuretano-aparrezko) kantitate ezberdinak betunetan gehitu ziren, betunaren pisuaren % 1etik % 5era. Betun bietan ikusi zen %5a baino gehiagoko polimeroa sartzeak laginak zakar bihurtzen zituen langarritasun eskasarekin eta, horren ondorioz, baztertu ziren. Bi nahaste bituminosozko laginak polimerozko %4ko portzentajearekin ekoiztu ziren. Marshall entseguak eraldatutako beroan egindako nahaste bituminosoetan egonkortasunean hobekuntzak eta deformazio txikiagoa erakutsi zituen ez eraldatutako laginekin konparatzean. Era berean, eraldatutako mastika bituminosoak identazio-balio txikiagoak erakutsi zituen ez eraldatutakoak baino, trafiko astuneko errepideetan erabiltzeko gai izanik. Ondorioz, hondakineko poliuretano-aparra etorkizun handiko betun eraldatzaile izan daitekeela atzematen da, betunaren propietateak hobetzen dituena

Bitumen modified with recycled polyurethane foam for employment in hot mix asphalt

A wide variety of modifiers have been applied to bitumen in order to enhance their properties and performance. Among them, polymers have been mainly used. The aim of this paper is to assess the use of polyurethane foam waste as a bitumen modifier for hot mix asphalts. The polyurethane foam is a by-product of the manufacturing of polyurethane for thermal insulation. From a bitumen with a penetration grade of 50/70, various samples with percentages of waste material in weight ranging from 1% to 5% were produced and tested. Samples with 5% of waste material or more became rough arid were refused due to their poor workability. A bituminous mixture with modified bitumen with a 4% of polyurethane was manufactured arid compared with a sample with the same aggregates and original bitumen. Results in Marshall test showed that a mix with polymer modified bitumen yielded improvements in stability and a lower deformability. This result suggests that the employment of polyurethane foam waste is a promising bitumen modifier, contributing also to recycle waste materials

A Series of Vertical Deflections, a Promising Traffic Calming Measure: Analysis and Recommendations for Spacing

Traffic calming measures (TCM) are placed in urban areas to improve road safety, and among them, vertical TCMs are widely employed. Many researches are focused on the influence of the geometry of each measure on speed reduction, but it is demonstrated that drivers forget its effect and speed up after it. Therefore, placing consecutive TCMs can help to maintain a safe area. However, scarce literature can be found about the adequate spacing between them. Hence, the aim of this paper is to analyze the adequate distance between TCMs. Various streets with variable distances and different vertical TCMs were evaluated in Poland and Spain, including raised crosswalks, raised intersections, speed humps and speed cushions. The intermediate point between two TCMs was selected as the place where the maximum speed is achieved. Results showed that there was a good correlation between the speeds at intermediate points and the distance between TCMs, with a determination coefficient around 0.80. For an 85th percentile of the speed under 50 km/h, a maximum distance of 200 m between TCMs is recommended, and for a value of 40 km/h, 75 m.This research was funded by “Eramus+ programme—Call 2016—KA1—Mobility of Staff in higher education—Staff mobility for teaching and training activities

Flexural Strength Prediction Models for Soil–Cement from Unconfined Compressive Strength at Seven Days

Soil⁻cement is an environmentally friendly road construction technique for base and subbase materials, which allows employing soils placed in the right-of-way of the road or in the surroundings, by improving its engineering properties. With this technique, it is possible to reduce the over-exploitation of quarries, the necessity of landfills and the pollutant gas emission due to the reduction of aggregate fabrication and transport. The manufacturing of soil⁻cement is generally controlled by means of the Uniaxial Compressive Strength (UCS) test at seven days, according to the regulations of each country. Nonetheless, one of the properties that best defines the performance of soil⁻cement is the Flexural Strength (FS) at long term, usually at 90 days. The aim of this paper is to develop new equations to correlate the UCS and the FS at long term and the UCS at seven days and at 90 days. Obtained results validate the proposed models and, hence, the flexural strength can be predicted from the Uniaxial Compressive Strength at seven days, allowing, if necessary, correcting measures (recalculation or rejection) in early stages of the curing time to be taken.In this research, part of the equipment funded by the Education Council of the Castille and Leon Government of Spain (Junta de Castilla y León) grant number BU009A06 and UB 07/03 was used. Conflicts of Interest: The authors declare no conflict of interest

Analysis and Economic Evaluation of the Use of Recycled Polyamide Powder in Masonry Mortars

Due to the considerable amount of waste plastics and polymers that are produced annually, the introduction of these waste products in construction materials is becoming a recurrent solution to recycle them. Among polymers, polyamide represents an important proportion of polymer waste. In this study, sustainable and lightweight mortars were designed and elaborated, substituting the aggregates by polyamide powder waste. Mortars were produced with various dosages of cement/aggregates, and the polyamide substitutions were 25, 50, 75, and 100% of the aggregates. The aim of this paper is to determine the density and the compressive strength of the manufactured mortars to observe the feasibility for being employed as masonry or rendering and plastering mortars. Results showed that with increasing polymer substitution, lower densities were achieved, ranging from 1850 to 790 kg/m3 in modified mortars. Mortars with densities below 1300 kg/m3 are cataloged as lightweight mortars. Furthermore, compressive strength also decreased with more polyamide substitution. Obtained values in recycled mortars were between 15.77 and 2.10 MPa, but the majority of the values (eight out of 12) were over 5 MPa. Additionally, an economic evaluation was performed, and it was observed that the use of waste polyamide implies an important cost reduction, apart from the advantage of not having to manage this waste material. Consequently, not only the mechanical properties of the new recycled materials were verified as well as its economic viability