Nourishing beaches and coastlines is a common practice in mitigating the effects of coastal erosion. Cullet, a geologically compatible aggregate, has been suggested for use in beach nourishment practices instead of dredged sands. The goal of this research is to assess the suitability of using of cullet to replace dredged sand as a nourishment aggregate and to educate the public about the potential uses for cullet as it relates to coastal erosion. The compatibility of cullet to natural quartz sand relies heavily on the comparison of physical characteristics of the grains and ecological compatibility, which compares the microorganisms that naturally exist on a sand grain to the microorganisms that occur on cullet in the same environment. Results show under the same environmental parameters, similar assemblages and amounts of microorganisms grow on both natural quartz and cullet substrates. Initial resistance to the concept of purposely putting broken glass onto a beach from coastal communities and their visitors is anticipated. An opinion survey to measure potential acceptance of the practice and to test the value of a hands-on educational program was conducted using both online and in-person platforms. These surveys will guide the development of an education program regarding mitigation of coastal erosion and the potential impacts of beach replenishment with cullet. Results show there is a concern regarding cullet in beach environments, but a hands-on learning approach may aide in acceptance. A comparison of sediment transport models that analyze the movement of a nourished shoreline and associated variables was conducted. This comparison determined a need for a model specifically accounting for morphological grain characteristics, the grains break down over time, and influences on the life of a nourishment project. The variables of importance include grain size evolution throughout the lifespan of a nourishment project, grain angularity, and composition relative to the native sediments of a nourished beach. Ambiguity of grain variables need further refinement with a forthcoming model. The biota and survey results show favor of cullet as a suitable beach fill material, however models including hardness and composition might contest the results related to project lifespans and overall suitability.

Removal of sediment by dredging causes excessive erosion and ecosystem disruption. The objective of this study is to consider recycled glass as a feasible, economical, and environmentally friendly alternative material for coastal replenishment. Recycled glass cullet possesses the same physical and chemical properties as natural quartz sand found on beaches. A field study conducted in Mississippi showed little variation across three depths. Analysis determined the sediment size ratio (or distribution) of beach sand and glass cullet. Results show the most common grain size of sand in Mississippi is 0.25 mm and the grain size of cullet is comparable. Analytical Spectral Data (ASD) assessed the compositional variation between the sediment and glass cullet. Comparative cost estimate shows glass cullet is indeed a feasible alternative aggregate to dredged sediment for beach replenishment and has the potential to protect shelf ecosystems from unnecessary dredging and create use for recycled glass. Keywords: glass, cullet, recycling, beaches, renourishment, analytical spectral device, feasibility

Doctor of Philosophy / Department of Civil Engineering / Kyle A. Riding / Finely ground glass has the potential for pozzolanic reactivity and can serve as a supplementary cementitious material (SCM). Glass reaction kinetics depends on both temperature and glass composition. Uniform composition, amorphous nature, and high silica content of glass make ground glass an ideal material for studying the effects of glass type and particle size on reactivity at different temperature. This study focuses on how three narrow size ranges of clear and green glass cullet, 63–75 [mu]m, 25–38 [mu]m, and smaller than 25 [mu]m, as well as combination of glass types and particle sizes affects the microstructure and performance properties of cementitious systems containing glass cullet as a SCM. Isothermal calorimetry, chemical shrinkage, thermogravimetric analysis (TGA), quantitative analysis of X-ray diffraction (XRD), and analysis of scanning electron microscope (SEM) images in backscattered (BS) mode were used to quantify the cement reaction kinetics and microstructure. Additionally, compressive strength and water sorptivity experiments were performed on mortar samples to correlate reactivity of cementitious materials containing glass to the performance of cementitious mixtures. A recently-developed modeling platform called “[mu]ic the model” was used to simulated pozzolanic reactivity of single type and fraction size and combined types and particle sizes of finely ground glass. Results showed that ground glass exhibits pozzolanic properties, especially when particles of clear and green glass below 25 [mu]m and their combination were used at elevated temperatures, reflecting that glass cullet is a temperature-sensitive SCM. Moreover, glass composition was seen to have a large impact on reactivity. In this study, green glass showed higher reactivity than clear glass. Results also revealed that the simultaneous effect of sizes and types of glass cullet (surface area) on the degree of hydration of glass particles can be accounted for through a linear addition, reflecting that the surface area would significantly affect glass cullet reactivity and that the effects of SCM material interaction on reaction kinetics were minimal. However, mechanical properties of cementitious systems containing combined glass types and sizes behaved differently, as they followed the weaker portion of the two particles. This behavior was attributed to the pores sizes, distruibution, and connectiity. Simulations of combined glass types and sizes showed that more work on microstructural models is needed to properly model the reactivity of mixed glass particle systems.

L'objectif de cette thèse est l'étude de la population de bulles générée entre deux morceaux de verre mis en contact et portés à 1100 °C sans matières premières. Comprendre la transition gaz dissous/gaz est un sujet scientifique majeur, par ailleurs les bulles sont le principal défaut dans les verres industriels et la quantité de verre recyclé introduite dans les fours est destinée à augmenter. Nous étudions la vie d'une bulle de sa nucléation à sa remontée dans le verre fondu en passant par sa croissance. Nous montrons que la nucléation homogène n'existe pas dans un verre car les réactions chimiques ne génèrent pas les sursaturations suffisantes. L'écoulement du verre après la transition vitreuse enferme des poches de gaz qui sont les précurseurs naturels des bulles. Nous modélisons la sursaturation à l'interface entre deux verres et montrons son influence sur le nombre de nuclei stables qui forment des bulles. Nous modélisons la dynamique de croissance des bulles en utilisant la même caractérisation de l'état d'oxydation que pour la nucléation. Nous constatons que la croissance des bulles à l'interface entre un verre réduit et un verre oxydé est plus rapide que celle des bulles situées dans un verre oxydé seul. Nous attribuons cette accélération à l'interaction entre les verres qui décale l'équilibre du soufre vers la formation de SO2 gazeux. Pour finir, nous présentons un montage expérimental qui permet de mesurer des champs de vitesse dans du verre grâce à l'utilisation de rayons X et à un algorithme de flot optique. Cette mesure permet d'évaluer la capacité d'une population de bulles à favoriser le mélange du verre au début de la fusion. / This thesis focuses on the bubbles population that appears between two glass pieces when heated at 1100 °C without any reactive raw materials. Understanding the mechanisms involved in the transition from dissolved gas to gas is still a fundamental issue of materials science. Industrially, bubbles are the major sources of defects in the final glass product and the amount of recycled glass introduced in glass furnaces will likely increase.We have studied the life of a bubble at different times, from its creation to its growth behavior, and to its rise in the molten glass. We show that homogeneous nucleation cannot exist in molten glass because chemical reactions are not able to generate the needed supersaturations by themselves. Thus, right after glass transition, glass flow is responsible for the entrapment of gas pockets, which then become natural precursors of bubbles.We model the supersaturation at the interface between two glasses, and we show its influence over the number of stable nuclei that can form bubbles.We also model the growth dynamic by using the same characterization of glasses' oxidation states than for nucleation. We experimentally show that bubbles located at the interface between a reduced glass and an oxidized glass grow faster than bubbles located in an oxidized glass only. The main effect of the interaction between the two glasses is to move the sulfur equilibrium towards the formation of gaseous SO2.Finally, using X-rays and an optical flow algorithm, we present a new experimental setup which measure velocity fields in an opaque medium to assess bubbles ability to promote glass mixing.

To combat the rapid degradation of the Louisiana coast, the Louisiana Coastal Protection and Restoration Authority has planned strategic land building initiatives throughout the Louisiana Gulf coast, including beach nourishment and marsh creation projects. It is commonly agreed that the state lacks sufficient renewable sediment resources to maintain the planned CPRA land building program. However, Louisiana, the state that commonly ranks last in state recycling percentage, recycles an estimated 0.6% of the waste glass consumed in the state. Glass is predominantly silica sand. This thesis evaluates laboratory‑determined characteristics of recycled crushed glass cullet to assess its suitability as a renewable aggregate for beach nourishment and marsh creation projects. Specifically, the research herein evaluates geotechnical and settling characteristics of recycled crushed glass cullet produced in Pearl River, Louisiana. Additionally, this research evaluates the effects on beach nourishment and marsh creation design parameters of blending this material with Gulf coastal sediments.

<p>Istraživanje u okviru doktorske disertacije obuhvata analizu mogućnosti<br />primene reciklaže otpadnog ambalažnog stakla radi dobijanja novog<br />proizvoda. Sa ciljem iznalaženja potencijalnog rešenja za postojeći problem<br />u oblasti upravljanja otpadnom staklenom ambalažom u Srbiji i načina za<br />poboljšanje održivosti u oblasti industrijske proizvodnje, testirana je<br />upotreba drobljenog otpadnog stakla u formi praha, kao sekundarne sirovine<br />u proizvodnji blokova od gline u ciglani. U skladu sa dobijenim<br />eksperimentalnim rezultatima i zaključkom da je 30% optimalna masena<br />količina staklenog praha koja može da se meša sa glinom kod praktične<br />proizvodnje blokova dobrog kvaliteta, razvijen je model, baziran na podacima<br />koji se odnose na konkretan primer. Rezultati modela u okviru analize<br />uticaja procesa proizvodnje blokova sa staklenim reciklatom na životnu<br />sredinu, kao i rezultati analize uticaja na cenu proizvodnje blokova<br />upotrebom staklenog reciklata, predstavljaju značajan doprinos kompletnom<br />sprovedenom istraživanju i usmeravaju na dalji tok istraživanja u oblasti<br />upotrebe otpada kao resursa u industrijskoj proizvodnji.</p> / <p>The research within doctoral dissertation includes a possibility analysis of applying<br />waste glass containers recycling in the production of new product. In order to find a<br />potential solution for the existing problem in the waste glass container management<br />in Serbia and to find a way to improve sustainability in the field of industrial<br />production, the use of waste glass cullet in powder form as a secondary raw material<br />in the clay block production was tested. In accordance with the obtained<br />experimental results and the conclusion that 30 wt. % is the optimal glass cullet<br />amount which can be mixed with clay in the practical production of good quality<br />blocks, a model, based on data related to the concrete example, has been developed.<br />The results of environmental impact assessment of clay/glass blocks production and<br />its costs, represent a significant contribution for complete research and focus on a<br />further research course in the field of waste utilization as a resource in industrial<br />production.</p>