Sustainable inorganic Binders and Their Applications in Building Engineering: A Green Alternative to Ordinary Portland Cement

In the last decades, the building materials and construction industry has been contributing to a great extent to generate a high impact on our environment. As it has been considered one of the key areas in which to operate to significantly reduce our footprint on environment, there has been widespread belief that particular attention now has to be paid and specific measures have to be taken to limit the use of non-renewable resources.The aim of this thesis is therefore to study and evaluate sustainable alternatives to commonly used building materials, mainly based on ordinary Portland Cement, and find a supportable path to reduce CO2 emissions and promote the re-use of waste materials. More specifically, this research explores different solutions for replacing cementitious binders in distinct application fields, particularly where special and more restricting requirements are needed, such as restoration and conservation of architectural heritage. Emphasis was thus placed on aspects and implications more closely related to the concept of non-invasivity and environmental sustainability. A first part of the research was addressed to the study and development of sustainable inorganic matrices, based on lime putty, for the pre-impregnation and on-site binding of continuous carbon fiber fabrics for structural rehabilitation and heritage restoration. Moreover, with the aim to further limit the exploitation of non-renewable resources, the synthesis of chemically activated silico-aluminate materials, as metakaolin, ladle slag or fly ash, was thus successfully achieved. New sustainable binders were hence proposed as novel building materials, suitable to be used as primary component for construction and repair mortars, as bulk materials in high-temperature applications or as matrices for high-toughness fiber reinforced composites.

Processi di biorefining per l'estrazione di secondary chemical building blocks da sottoprotti dell'agro-industria

Phenol and cresols represent a good example of primary chemical building blocks of which 2.8 million tons are currently produced in Europe each year. Currently, these primary phenolic building blocks are produced by refining processes from fossil hydrocarbons: 5% of the world-wide production comes from coal (which contains 0.2% of phenols) through the distillation of the tar residue after the production of coke, while 95% of current world production of phenol is produced by the distillation and cracking of crude oil. In nature phenolic compounds are present in terrestrial higher plants and ferns in several different chemical structures while they are essentially absent in lower organisms and in animals. Biomass (which contain 3-8% of phenols) represents a substantial source of secondary chemical building blocks presently underexploited. These phenolic derivatives are currently used in tens thousand of tons to produce high cost products such as food additives and flavours (i.e. vanillin), fine chemicals (i.e. non-steroidal anti-inflammatory drugs such as ibuprofen or flurbiprofen) and polymers (i.e. poly p-vinylphenol, a photosensitive polymer for electronic and optoelectronic applications). European agrifood waste represents a low cost abundant raw material (250 millions tons per year) which does not subtract land use and processing resources from necessary sustainable food production. The class of phenolic compounds is essentially constituted by simple phenols, phenolic acids, hydroxycinnamic acid derivatives, flavonoids and lignans. As in the case of coke production, the removal of the phenolic contents from biomass upgrades also the residual biomass. Focusing on the phenolic component of agrifood wastes, huge processing and marketing opportunities open since phenols are used as chemical intermediates for a large number of applications, ranging from pharmaceuticals, agricultural chemicals, food ingredients etc. Following this approach we developed a biorefining process to recover the phenolic fraction of wheat bran based on enzymatic commercial biocatalysts in completely water based process, and polymeric resins with the aim of substituting secondary chemical building blocks with the same compounds naturally present in biomass. We characterized several industrial enzymatic product for their ability to hydrolize the different molecular features that are present in wheat bran cell walls structures, focusing on the hydrolysis of polysaccharidic chains and phenolics cross links. This industrial biocatalysts were tested on wheat bran and the optimized process allowed to liquefy up to the 60 % of the treated matter. The enzymatic treatment was also able to solubilise up to the 30 % of the alkali extractable ferulic acid. An extraction process of the phenolic fraction of the hydrolyzed wheat bran based on an adsorbtion/desorption process on styrene-polyvinyl benzene weak cation-exchange resin Amberlite IRA 95 was developed. The efficiency of the resin was tested on different model system containing ferulic acid and the adsorption and desorption working parameters optimized for the crude enzymatic hydrolyzed wheat bran. The extraction process developed had an overall yield of the 82% and allowed to obtain concentrated extracts containing up to 3000 ppm of ferulic acid. The crude enzymatic hydrolyzed wheat bran and the concentrated extract were finally used as substrate in a bioconversion process of ferulic acid into vanillin through resting cells fermentation. The bioconversion process had a yields in vanillin of 60-70% within 5-6 hours of fermentation. Our findings are the first step on the way to demonstrating the economical feasibility for the recovery of biophenols from agrifood wastes through a whole crop approach in a sustainable biorefining process.

Untangle sustainable development goal 8 through data visualization and HCI methods

Following the approval of the 2030 Agenda for Sustainable Development in 2015, sustainability became a hotly debated topic. In order to build a better and more sustainable future by 2030, this agenda addressed several global issues, including inequality, climate change, peace, and justice, in the form of 17 Sustainable Development Goals (SDGs), that should be understood and pursued by nations, corporations, institutions, and individuals. In this thesis, we researched how to exploit and integrate Human-Computer Interaction (HCI) and Data Visualization to promote knowledge and awareness about SDG 8, which wants to encourage lasting, inclusive, and sustainable economic growth, full and productive employment, and decent work for all. In particular, we focused on three targets: green economy, sustainable tourism, employment, decent work for all, and social protection. The primary goal of this research is to determine whether HCI approaches may be used to create and validate interactive data visualization that can serve as helpful decision-making aids for specific groups and raise their knowledge of public-interest issues. To accomplish this goal, we analyzed four case studies. In the first two, we wanted to promote knowledge and awareness about green economy issues: we investigated the Human-Building Interaction inside a Smart Campus and the dematerialization process inside a University. In the third, we focused on smart tourism, investigating the relationship between locals and tourists to create meaningful connections and promote more sustainable tourism. In the fourth, we explored the industry context to highlight sustainability policies inside well-known companies. This research focuses on the hypothesis that interactive data visualization tools can make communities aware of sustainability aspects related to SDG8 and its targets. The research questions addressed are two: "how to promote awareness about SDG8 and its targets through interactive data visualizations?" and "to what extent are these interactive data visualizations effective?".

Analysis of urban infrastructure for sustainable mobility through instrumented bicycles for students

In Europe almost 80% of the continent's population lives in cities. It is estimated that by 2030 most regions in Europe which contain major cities will have even more inhabitants on 35–60% more than now. This process generates a consequent elevate human pressure on the natural environment, especially around large urban agglomerations. Cities could be seen as an ecosystem, represented by the dominance of humans that re-distribute organisms and fluxes and represent the result of co-evolving human and natural systems, emerging from the interactions between humans, natural and infrastructures. Roads have a relevant role in building links between urban components, creating the basis on which it is founded the urban ecosystem itself. This thesis is focused on the research for a comprehensive model, framed in European urban health & wellbeing programme, aimed to evaluate the determinants of health in urban populations. Through bicycles, GPS and sensor kits, specially developed and produced by University of Bologna for this purpose, it has been possible to conduct on Bologna different direct observations that oriented the novelty of the research: the categorization of university students cyclists, connection among environmental data awareness and level of cycling, and an early identification of urban attributes able to impact on road air quality and level of cycling. The categorization of university students’ cyclist has been defined through GPS analysis and focused survey, that both permit to identify behavioural and technical variables and attitudes towards urban cycling. The statistic relationship between level of cycling, seen as number of bicycles passages per lane and pollutants level, has been investigated through an inverse regression model, defined and tested through SPSS software on the basis of the data harvest. The research project that represents a sort of dynamic mobility laboratory on two wheels, that permits to harvest and study detected parameters.

The green finance apparatus. How ideology and planning steer sustainable capital flows

By investigating the inner working of leading financial institutions, and their dense interconnections, this thesis explores the evolution of traditional financial instruments like bonds to tackle sustainability issues. Building on fieldwork among green financiers, the thesis is based upon participant observation of working groups appointed to define standards for sustainable bonds. Engaging critical theory, one claim is that investors are increasingly recruited or interpellated by an emerging global green ideological apparatus, aimed at ensuring the reproduction of existing social relations. Taking stock of the proliferation of both public and private actors in the definition of green standards and practices, the thesis proposes that this green ideology is becoming hegemonic. Focusing on the case of green bond pricing, it suggests that environmental and climate labels and other financial green signifiers for financial products take on brand-like qualities. Crystallizing imaginaries, meanings, and forms of personhood, they play a fundamental role in what is defined as a dual process of valuation-cum-subjectivation. Identifying themselves as “green”, financiers valuate differently green and brown assets allowing a ‘green’ financial value to slowly come to matter. Yet, alongside their ideological role, green labels have come to be almost exclusively standardized with reference to specific Climate Scenarios (e.g. Net Zero). These scenarios coordinate the optimal path towards achieving a carbon neutral world and represent the quintessential example of socioeconomic planning, crucially undermining neoliberal ideas of ‘the market’ as the ultimate calculative device.