Esta investigación, estudia el efecto que produce el cemento, cal, geomalla y principalmente la ceniza de madera como componente mejorador de un suelo arcilloso, con el fin de evaluar las deformaciones verticales en la subrasante de un pavimento convencional a los 7 y 21 días de cura. La ceniza de madera es un residuo que proviene de la quema de materiales orgánicos en los hornos de las ladrilleras artesanales presentes en todo el Perú, los cuales el carbón, aserrín y madera, son los más utilizados. La disposición de éste material, genera problemas ambientales. Se realizaron ensayos de laboratorio para caracterizar la ceniza de madera, la mezcla de arcilla-ceniza, la mezcla arcilla-cemento, arcilla-cal y el refuerzo con la geomalla para luego modelarlo con la ayuda de la herramienta computacional Plaxis 8.2, software de elementos finitos, y obtener las deformaciones verticales. Se comprueba que con la geomalla biaxial se obtuvieron las menores deformaciones seguido por la mezcla arcilla-cemento. Con respecto a la arcilla-ceniza (21 días) se obtuvo un comportamiento similar a la mezcla de arcilla-cal (7días) siendo este resultado muy significativo ya que la ceniza al ser un material residuo de las ladrilleras puede llegar a un comportamiento mecánico tan igual como la cal. / This research studies the effect produced by cement, lime, geogrid and mainly wood ash as an improving component of a clayey soil, in order to evaluate the vertical deformations in the subgrade of a conventional pavement at 7 and 21 days after cure. Wood ash is a residue that comes from the burning of organic materials in the kilns of artisanal brickmakers present throughout Peru, which coal, sawdust and wood, are the most used. The disposition of this material generates environmental problems. Laboratory tests were carried out to characterize the wood ash, the clay-ash mixture, the clay-cement mixture, the clay-lime and the reinforcement with the geogrid, and then model it with the help of the computer tool Plaxis 8.2, elements software finite, and get the vertical deformations. It is verified that with the biaxial geogrid the smallest deformations were obtained followed by the clay-cement mixture. With respect to ash-clay (21 days) a behavior similar to the clay-lime mixture (7 days) was obtained, this result being very significant since the ash being a material residue of the brickworks can reach such a mechanical behavior just like lime. / Tesis

Orientador: Ana Maria Rodrigues Cassiolato / Resumo: O solo degradado em estudo originou-se pela retirada da sua camada superficial, que compreende a vegetação, a matéria orgânica, os nutrientes e os microrganismos, cujos processos são essenciais para o solo ser considerado produtivo. Sua recuperação é importante para manter o equilíbrio da biodiversidade de flora e fauna e protege-lo contra a erosão, entre outros fatores. O objetivo deste trabalho foi o condicionamento do subsolo pela adição de cinza de biomassa de cana-de-açúcar, da inoculação de fungo micorrízico arbuscular (FMA – Glomus clarum) e da inoculação de fungos e de bactéria solubilizadores de fosfato, buscando uma técnica para a recuperação de solos degradados. A bananeira (Musa sp. cv. Mysore) foi utilizada como planta indicadora para as modificações que ocorreram no solo. O delineamento experimental foi em blocos casualizados, em esquema fatorial 2 x 2 x 3 + 2, com 4 repetições por tratamento, totalizando 12 tratamentos, com 4 repetições (bloco). O primeiro fator foi com e sem inoculação de FMA, o segundo foi com e sem adição de cinza proveniente da queima do bagaço de cana-de-açúcar, o terceiro foi com e sem inoculação de fungos e de bactéria solubilizadores de fosfato, e dois tratamentos adicionais, área conservada de Cerrado (SCRC) e área degradada sem intervenção (ADSI). Após 67 e 274 dias do plantio foram avaliados os atributos químicos e microbiológicos do solo na camada de 0,0 a 0,10 m, além da altura, do diâmetro, do índice relativo de clorofila e do P t... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The degraded soil under study originated by the removal of the superficial layer, which includes vegetation, organic matter, nutrients and microorganisms, whose processes are essential for the soil to be considered productive. Its recovery is important to maintain the balance of biodiversity of flora and fauna and protect it against erosion, among other factors. The objective of this work was the subsoil conditioning by the addition of sugarcane biomass ash, the inoculation of arbuscular mycorrhizal fungi (AMF - Glomus clarum) and the inoculation of fungi and bacteria phosphate solubilizers, searching for a technique for recovery of degraded soils. The banana plants (Musa sp. cv. Mysore) was used as an indicator plant for the changes that occurred in the soil. The experimental design was a randomized complete block design, with a 2 x 2 x 3 +2 factorial scheme, with 4 replicates per treatment, in a total of 12 treatments, with 4 replicates (block). The first factor was with and without AMF inoculation, the second was with and without ash added from the burning of sugarcane bagasse, the third was with and without inoculation of fungi and bacteria phosphate solubilizers and two controls area, Cerrado conservation area (CCAR) and degraded area without intervention (DAWI). After 67 and 274 days of planting, the soil chemical and microbiological attributes were evaluated in the 0.0 to 0.10 m layer, as well as the height, diameter, relative chlorophyll index, and total leaf P. The a... (Complete abstract click electronic access below) / Mestre

In recent decades, advances in low NOₓ coal combustion and increasingly strict CO₂ reduction mandates have changed power plant boiler operations quite significantly. As a result of these necessary efforts, the characteristics of fly ash generated at many power plants have also changed. In particular, increases in unburned carbon content have been observed with detrimental implications on the utility of these fly ashes in concrete applications. Over the same time period, the combustion of biomass for energy generation has received increased attention due to the potential benefits of reducing CO₂ emissions and improved sustainability when compared to fossil fuel combustion. Biomass is directly burned, gasified, or co-fired with coal to achieve this goal. Currently, close to 120 million metric tons of coal combustion by products are produced in the U.S. annually. As with coal combustion, production of energy from biomass combustion/gasification results in significant by-product generation that must either be productively reused or geologically disposed. While much research effort has been devoted to understanding the properties and potential productive reuse alternatives for coal combustion residuals, relatively little work has been done on the by-products of biomass combustion. This study investigated the properties and engineering behavior of sixteen ash samples that were produced in eleven different power plants. Specifically, three high carbon content Class F fly ashes, eight coal and biomass co-fired ashes, three pure biomass ash samples, and two high quality, low carbon content ash samples, one of which is commercially marketed (for reference) were chosen. The various ash samples were characterized by means of: electron microscopy; laser diffraction and dry sieve particle size analysis; loss on ignition and total organic carbon analysis; specific surface area analysis; as well as x-ray fluorescence and x-ray diffraction. The ash samples were also investigated for their potential engineering application in the fired clay brick industry, as low-cost adsorptive agents, and in alkali activated geopolymer synthesis for geotechnical and geoenvironmental applications. Results from physical and chemical characterization of the ash samples show no significant differences between pure coal ash and coal co-fired with biomass ash samples from the same power plant. However, there are significant morphological, chemical, and mineralogical differences between coal ash and pure biomass ash. Unlike pure coal ash, biomass ash is not composed primarily of aluminosilicate glass cenospheres but rather consists mainly of charred, fibrous woody remnants with elevated calcite content as compared to coal ash. Bench scale fired bricks produced by partial replacement of clay material with high carbon coal ash, co-fired ash, and pure biomass ash, respectively, was successful. Physical properties of a number of the mix designs exceeded the highest ASTM weathering grade requirements. As sorptive agents, high carbon concentrates from coal and co-fired ash samples, along with all the biomass ash samples, showed significant uptake of lead. The unaltered as- received ash samples (i.e. no acid or steam activation) showed only moderate arsenic (V) and selenium (VI) sorption capacity. Finally, solidification/stabilization by geopolymerization of high carbon content, co-fired ash with as little as 3 molar NaOH in the activator solution was successful, possibly paving the way for various geotechnical and geoenvironmental applications in ground improvement and soil/ash-pond stabilization.

<p>U disertaciji su prikazani rezultati sopstvenog eksperimentalnog istraživanja mogućnosti primjene biopepela, nastalog sagorjevanjem žetvenih ostataka, kao mineralnog dodatka u cementnim kompozitima: malterima i betonima. Istraživanje je zasnovano na komparativnoj analizi 27 vrsta maltera u kojima je varirana vrsta biopepela i vrsta sitnozrnog agregata i 12 vrsta betona koje se razlikuju u vrsti veziva i u krupnom agregatu. Na očvrslom malteru su ispitani: konzistencija, čvrstoća pri pritisku i kapilarno upijanje vode, a na očvrslom betonu ispitivani su kapilarno upijanje vode, skupljanje pri sušenju, čvrstoća pri pritisku, dinamički modul elastičnosti, otpornost na habanje, vodonepropustljivost i čvrstoća na savijanje. Istaknuto je da se primjenom biopepela kao zamjene dijela cementa mogu dobiti konstrukcijski malteri i betoni, odnosno betoni sa zadovoljavajućim fizičkim i mehaničkim karakteristikama.</p> / <p>The dissertation presents the results of an own experimental research on the possibility of using biomass ash as a mineral additive in cement composites: mortar and concrete. The research is based on a comparative analysis of 27 types of mortars in which the type of biomass ash and the type of fine-grained aggregate were varied, as well as 12 types of concrete that differ in the type of binder and coarse aggregate. Following properties were tested on hardened mortars: consistency, compressive strength and capillary water absorption, and on hardened concrete: capillary water absorption, drying shrinkage, compressive strength, dinamic modulus of elasticity, wear resistance, waterpermeability and flexural strength. It was pointed out that biomass ash can be used as a replacement of a part of cement, thereby obtaining satisfactory physical and mechanical characteristics.</p>

The construction industry is the largest consumer of materials in our society. Approximately 40% of all materials used are related to this section of the industry. Equivalent is the impact of the sector’s activities to the environment in terms of non-renewable energy sources (grey energy), gas emissions (mainly CO2), solid waste, etc. With concrete being the most widely used construction material (second only to water in total volumes consumed annually by society) and cement being the essential “glue” in concrete, emphasis should be placed on investigating and enforcing appropriate ways, methodologies and policies, to make cement manufacturing and the construction industry in general a more environmental friendly sector. At the same time, by considering, at one hand the significant amount of research and breakthroughs achieved on structural materials and design, as well as the level of sophistication of the modern European Standards and structural codes, and on the other hand, the increasing cases of premature deterioration of concrete structures, particular emphasis should also be placed on safeguarding the service life of reinforced concrete structures (in addition to tackling their environmental burden). That is why it is very important to introduce the sustainable way of thinking and the concept of industrial ecology on the preliminary design stages of a structure, on the material selection process and on the service life estimation stage, in achieving a robust durable reinforced concrete (RC) structure (for a given service life) with the minimum environmental burden. Thus, the main objective of the present Thesis is to focus on identifying and quantifying a structured framework of the appropriate methodologies in formulating an Integrated Design Process (IDP) for the design of durable and sustainable structures at the minimum environmental and economical cost (without compromising issues of structural safety) and also in identifying and demonstrating ways of industrial ecology for the sustainable development of the cement and construction industry. The present Thesis contributes to the evaluation of the environmental cost of each component of concrete and to provide the best possible mix design configuration (by means of a holistic analytical software tool) in terms of low environmental cost, as well as, to assess this proposed configuration in terms of strength and durability requirements. Overall, it has to be emphasized that through the present Thesis a new indicator is proposed for design purposes: the environmental cost, which can be added to the existing strength, durability and economic cost indicators towards an integrated design optimization of concrete structures. Finally, it is concluded that the incorporation of new Supplementary Cementing Materials (SCM), as biomass ashes and especially Rice Husk Ash (RHA), offers new perspectives for decreasing the environmental cost of constructions. / Η κατασκευαστική βιομηχανία αποτελεί τον μεγαλύτερο καταναλωτή υλικών στην κοινωνία μας. Περίπου το 40% όλων των υλικών που χρησιμοποιούνται σχετίζονται με αυτόν τον τομέα της βιομηχανίας. Αντίστοιχο αντίκτυπο έχουν και οι δραστηριότητες του τομέα στο περιβάλλον σε ότι αφορά τις μη ανανεώσιμες πηγές ενέργειας («γκρίζα» ενέργεια), αέριες εκπομπές (κυρίωςCO2 ), στερεά απόβλητα, κλπ. Δεδομένου ότι το σκυρόδεμα αποτελεί το πιο ευρέως χρησιμοποιούμενο δομικό υλικό (δεύτερο μετά το νερό σε συνολικούς όγκους που καταναλώνονται ετησίως από την κοινωνία) και ότι το τσιμέντο είναι η απαραίτητη «κόλλα» στο σκυρόδεμα, έμφαση πρέπει να δοθεί στη διερεύνηση και επιβολή κατάλληλων τρόπων, μεθοδολογιών και πολιτικών για τη μετατροπή της τσιμεντοβιομηχανίας και της κατασκευαστικής βιομηχανίας σε έναν γενικά περισσότερο περιβαλλοντικά φιλικό τομέα. Ταυτόχρονα, λαμβάνοντας υπόψη από τη μια μεριά τη σημαντική ποσότητα έρευνας και τα επιτεύγματα σχετικά με τα δομικά υλικά και τον σχεδιασμό, και επιπλέον το επίπεδο της επιτήδευσης των σύγχρονων Ευρωπαϊκών Προτύπων και κατασκευαστικών κανονισμών, και από την άλλη μεριά τις αυξανόμενες περιπτώσεις της πρώιμης φθοράς των κατασκευών από σκυρόδεμα, ιδιαίτερη έμφαση θα πρέπει να δοθεί στη διασφάλιση της διάρκειας ζωής των κατασκευών οπλισμένου σκυροδέματος (σε συνδυασμό με την αντιμετώπιση της περιβαλλοντικής τους επιβάρυνσης). Για το λόγο αυτό είναι ιδιαίτερα σημαντική η εισαγωγή του βιώσιμου τρόπου σκέψης και της έννοιας της βιομηχανικής οικολογίας στα προκαταρκτικά στάδια σχεδιασμού μιας κατασκευής, κατά τη διαδικασία επιλογής υλικών και κατά το στάδιο εκτίμησης της διάρκειας ζωής, ώστε να επιτευχθεί μια εύρωστη, ανθεκτική κατασκευή οπλισμένου σκυροδέματος (για δεδομένη διάρκεια ζωής) με την ελάχιστη περιβαλλοντική επιβάρυνση. Συνεπώς, ο κύριος στόχος της παρούσας Διατριβής είναι να επικεντρωθεί στον εντοπισμό και ποσοτικοποίηση ενός δομημένου προτύπου κατάλληλων μεθοδολογιών για τον σχηματισμό μιας Ενοποιημένης Διαδικασίας Σχεδιασμού για τον σχεδιασμό ανθεκτικών και βιώσιμων κατασκευών με το ελάχιστο περιβαλλοντικό και οικονομικό κόστος (χωρίς συμβιβασμούς σε θέματα που άπτονται της κατασκευαστικής ασφάλειας) και επίσης για την αναγνώριση και επίδειξη τρόπων βιομηχανικής οικολογίας για την βιώσιμη ανάπτυξη της βιομηχανίας τσιμέντου και σκυροδέματος. Η παρούσα Διατριβή συνεισφέρει στην αξιολόγηση του περιβαλλοντικού κόστους κάθε συστατικού του σκυροδέματος αλλά και στην παροχή ενός καλύτερου δυνατού σχεδιασμού σύνθεσης σκυροδέματος (μέσω ενός ολιστικού αναλυτικού λογισμικού) υπό όρους χαμηλού περιβαλλοντικού κόστους, καθώς και στο να αξιολογήσει την προτεινόμενη σύνθεση υπό όρους αντοχής και απαιτήσεων ανθεκτικότητας. Συνολικά, πρέπει να τονισθεί ότι στη παρούσα Διατριβή προτείνεται για πρώτη φορά ένας νέος δείκτης για σκοπούς σχεδιασμού: το περιβαλλοντικό κόστος, το οποίο μπορεί να προστεθεί στους υπάρχοντες δείκτες αντοχής, ανθεκτικότητας και οικονομικού κόστους προς μια ολοκληρωμένη αριστοποίηση σχεδιασμού κατασκευών από σκυρόδεμα. Τέλος, προκύπτει το συμπέρασμα ότι η ενσωμάτωση νέων συμπληρωματικών υδραυλικών υλικών (SCM: Supplementary Cementing Materials), όπως οι τέφρες βιομάζας και ειδικά η τέφρα φλοιού ρυζιού (RHA: Rice Husk Ash), προσφέρει νέες προοπτικές για τη μείωση του περιβαλλοντικού κόστους σκυροδέματος.