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This study explored the morphological, mineralogical, and physico-chemical features of carcinogenic erionite and other possibly hazardous zeolites, such as mesolite and thomsonite, while also investigating the interacting capability of the mineral surface at the liquid/solid interface. Extremely fibrous erionite is K+ and Ca2+-rich and shows the highest Si/Al ratio (3.38) and specific surface area (8.14 m2/g). Fibrous mesolite is Na+ and Ca2+-rich and displays both a lower Si/Al ratio (1.56) and a smaller specific surface area (1.56 m2/g). The thomsonite composition shows the lowest values of Si/Al ratio (1.23) and specific surface area (0.38 m2/g). Electron paramagnetic resonance data from selected spin probes reveal that erionite has a homogeneous site distribution and interacts well with all spin probes. The surfaces of mesolite and thomsonite are less homogeneous and closer polar sites were found through consequent interaction with the probes. The mesolite surface can also clearly interact but with a lower strength and may represent a potential health hazard for humans, though with a lower degree if compared to erionite. The thomsonite surface is not inert and interacts with the probes with a low-grade capability. We can expect small fragments of thomsonite to interact with the biological environment, though with a low-grade intensity.

This chapter focuses on the analysis of the heat transfer phenomena characterising energy geostructures in a time-dependent framework that is representative of transient conditions. Analytical approaches to model heat transfer at both relatively long and short-to-medium timescales, around and within geothermal heat exchangers such as energy geostructures, respectively, are presented. The developments proposed in this chapter can characterise, together with the time-independent analytical solutions treated in Chapter 8, Analytical modelling of steady heat and mass transfers, many heat transfer problems involved with the operation of energy geostructures. Although more approximate than the numerical methods treated in Chapter 12, Numerical modelling of energy geostructures, the proposed analytical approaches can be considered powerful tools for the thermohydraulic analysis of energy geostructures.

This chapter focuses on the performance-based design of energy piles subjected to axial mechanical loads and thermal loads. A general design methodology to verify the geotechnical and structural performance of energy piles against the influence of thermal and mechanical loads is proposed, and design criteria and approaches that may be considered for this aim are expanded. The previous subjects are addressed with reference to the Eurocodes, but they may be extended to other performance-based standards and frameworks via potential modifications. The developments presented in this chapter resort to the knowledge treated in Part D of this book, complement the design considerations discussed in Chapter 13, Performance-based design in the context of energy geostructures, and Chapter 14, Determination of design parameters for energy geostructures, and allow developing the performance-based design of energy piles in many of the situations that are likely to be encountered in practice.

This chapter presents a theoretical treatment of deformation phenomena that can occur under nonisothermal conditions associated with heat transfer processes in the context of energy geostructures. The relevance of deformation under nonisothermal conditions is highlighted with respect to its role in the characterisation of the reversible and irreversible thermomechanical behaviour of materials, and thus of energy geostructures. A framework resorting to the essentials of the theories of thermoelasticity, plasticity and thermoplasticity is proposed to understand, model and predict deformation phenomena, and key features of such theories are expanded for the considered aims. This chapter complements the knowledge treated in Chapter 3, Heat and mass transfers in the context of energy geostructures, and serves as a basis for various developments proposed in Parts C–E of this book.

This chapter focuses on the analysis of the heat and mass transfer phenomena characterising energy geostructures in a time-independent framework that is representative of steady conditions. Relevant reference time and space scales allowing the modelling of heat and mass transfers under the considered conditions are discussed, and the analytical analysis of heat and mass transfer phenomena within and around energy geostructures is presented via the consideration of the processes involved with the flow of a heat carrier fluid in pipes. The developments proposed in this chapter serve as a basis for the time-dependent analytical analysis of heat transfer that constitutes Chapter 9, Analytical modelling of transient heat transfer.

This chapter focuses on the analysis of the capacity and deformation of single energy piles subjected to axial mechanical loads and thermal loads. Analytical approaches to model the failure of energy piles induced by axial mechanical loads are proposed, while semianalytical approaches to predict the axial deformation of such foundations subjected to thermal loads, applied alone or in conjunction with mechanical loads, are highlighted. The predictions resulting from the application of the discussed approaches are compared with full-scale in situ test results, and the capabilities of such methods are discussed. The developments proposed in this chapter serve as a basis for the analytical analysis of the capacity and deformation of energy pile groups that is addressed in Chapter 11, Analytical modelling of capacity and deformation of energy pile groups.

This chapter presents a theoretical treatment of heat and mass transfers in the context of energy geostructures. The relevance of heat and mass transfers is highlighted with respect to their role in the characterisation of the thermohydraulic behaviour of materials, and thus of energy geostructures, through the flow of thermal energy and fluid volumes. The developments treated in this chapter prepare for the analysis of deformation phenomena under nonisothermal conditions that is addressed in Chapter 4, Deformation in the context of energy geostructures, as well as for the understanding of various aspects addressed in Parts C, D and E of this book.

This chapter focuses on the experimental analysis of the thermohydromechanical behaviour of soils and soil–structure interfaces based on the results of laboratory tests. The behaviour of soils as well as soil–structure interfaces is expanded with a focus on their deformation and strength under nonisothermal conditions. The influence of aspects that govern such behaviour are highlighted. The developments proposed in this chapter serve as a basis for the treatment of the response of energy geostructures to mechanical and thermal loads discussed in Chapter 6, Thermo-mechanical behaviour of single energy piles, and Chapter 7, Thermo-mechanical behaviour of energy pile groups, as well as for the content of the Parts C, D and E of this book.

This chapter focuses on the numerical modelling of the thermohydromechanical behaviour of energy geostructures for typical technical solutions and site conditions that can characterise such applications. The previous factors include, without being limited to (1) the pipe configuration, (2) the geostructure geometry, (3) the heat carrier fluid flow rate circulating in the pipes, (4) the soil–geostructure thermal expansion coefficient ratio and (5) the soil–geostructure thermal conductivity ratio. Comments on the capability of numerical simulations to capture observed responses of energy geostructures are highlighted and remarks of practical significance are summarised. The developments presented in this chapter allow achieving advanced information on the multiphysical response of energy geostructures in many of the situations that are likely to be encountered in practice.

This chapter focuses on the experimental analysis of the response of energy pile groups to the mechanical and thermal loads associated with the coupled structural support and heat exchanger role of such foundations based on the results of full-scale in situ tests. The analysis expands on the temperature, strain and stress variations characterising energy pile groups and highlights aspects of crucial importance for the comprehensive analysis of the thermomechanical behaviour of such geostructures. The developments presented in this chapter complement the treatment of the response of single energy piles to mechanical and thermal loads discussed in Chapter 6, Thermomechanical behaviour of single energy piles.

This chapter focuses on the design of details unprecedentedly characterising energy geostructures, in contrast to conventional geostructures, which are required for the expedient yet effective application of this technology as well as for their optimal operation and performance. Attention is given in this framework to the design of the features that may preferably be employed for the piping network installed within and between energy geostructures. In the treatment of these aspects, reference is made to recommendations available at the national level in Switzerland, United Kingdom and France as well as to practical experience in this scope. The developments presented in this chapter complement the design considerations discussed in Chapters 13–15 and may be considered from the analysis to the design and construction phases of energy geostructures.

The mechanical behaviour of frozen ground and permafrost is changing under the increasing variation of environmental and anthropogenic boundary conditions. This phenomenon affects many civil structures and infrastructures built in Polar and Alpine areas. Mathematical formulations able to capture the mechanical behaviour of frozen ground and permafrost with adherence to reality and a limited employment of technical resources and time appear crucial for the engineering design and retrofit of these structures. To address this challenge, this study presents a relatively simple elasto-plastic constitutive model for capturing the non-linear mechanical behaviour of frozen silt. The model is based on associated flow rules. It employs an elliptical yield surface and a parabolic yield surface for describing the volumetric mechanisms that characterise the modelled material, together with a parabolic yield surface for describing the deviatoric mechanism. Comparisons with experimental triaxial test results available in the literature highlight the suitability of the model to capture the non-linear mechanical response of frozen silt subjected to both low and high confining pressures. This result, together with the doable implicit consideration in the model of the effects induced by environmental boundary conditions such as temperature on the mechanical behaviour of the material, makes this tool attractive for simplified yet thorough analyses of frozen ground and permafrost-related problems.

Although asbestos represents today one of the most harmful contaminant on Earth, in 72% of the countries worldwide only amphiboles are banned while controlled use of chrysotile is allowed. Uncertainty on the potential toxicity of chrysotile is due to the fact that the mechanisms by which mineral fibres induces cyto- and geno-toxic damage are still unclear. We have recently started a long term project aimed at the systematic investigation of the crystal-chemistry, bio-interaction and toxicity of the mineral fibres. This work presents a systematic structural investigation of iron in asbestos and erionite (considered the most relevant mineral fibres of social and/or economic-industrial importance) using synchrotron X-ray absorption and Mossbauer spectroscopy. In all investigated mineral fibres, iron in the bulk structure is found in octahedral sites and can be made available at the surface via fibre dissolution. We postulate that the amount of hydroxyl radicals released by the fibers depends, among other factors, upon their dissolution rate; in relation to this, a ranking of ability of asbestos fibres to generate hydroxyl radicals, resulting from available surface iron, is advanced: amosite > crocidolite ≈ chrysotile > anthophyllite > tremolite. Erionite, with a fairly high toxicity potential, contains only octahedrally coordinated Fe 3+ . Although it needs further experimental evidence, such available surface iron may be present as oxide nanoparticles coating and can be a direct cause of generation of hydroxyl radicals when such coating dissolves.

Asbestos containing materials (ACMs) are a class of hazardous waste whose management has become a matter of great concern. A major open issue is whether ACM wastes, produced after reclamation, should be destined to landfill burial or recycling. After a short history of asbestos as building material, classification, properties and health effects of asbestos minerals, this chapter will describe the methods for the reclamation and disposal of ACMs and attractive recycling solutions as a safe alternative to landfill disposal. Amongst them, recycling of thermally treated cement asbestos for the production of concrete and geopolymers will be illustrated in detail.