Electrical discharge coating (EDC) is a surface modification process used to produce hard coatings from a sacrificial powder metallurgy (PM) tool electrode onto a target workpiece. However, the integrity of as-processed EDC surfaces, as reported on in literature, is generally poor, with limited understanding of the fundamental interactions between energy source and workpiece material, and the microstructural development of the surfaces created. This thesis explores, at the nano-scale, the deposition and microstructural development of ED processed cermet coatings. Emphasis is given to TiC-based ED coatings, prepared using a semi-sintered TiC tool electrode. A comprehensive study of TiC/Fe cermet coating microstructural development, as a function of ED processing conditions (current 2 - 19 A; pulse-on time 2 - 64 μs) is presented, using the combined characterisation techniques of scanning electron microscopy (SEM) / energy dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD) and cross-sectional transmission electron microscopy (TEM). The ED coatings were composites in nature, with complex banded nanostructures of TiC grains within an Fe matrix. Preferred TiC/Fe ED coatings on 304-SS, achieved under conditions of low processing energy (10 A current and 8 μs pulse-on time), exhibited low levels of cracks and porosity, with hardness values of ~ 1800 HV. The fraction of energy transferred to the workpiece, Fv, as a consequence of ED sparking, is an important parameter which affects directly individual crater geometry and the microstructural development of the near surface modified layer. Hence, a 2D transient heat transfer model is presented, using finite difference methods, and used to estimate effective values for Fv as a function of processing conditions, and thereby to predict coating layer thicknesses of developed microstructures through appropriate consideration of heat flow into the system. The model is validated against previous work in literature and with experimental observations. The modelling demonstrated a variation of energy transferred to the workpiece, of 17 - 23% for increasing current from 2 - 19 A at fixed pulse-on time of 8 μs; and 7 - 53% for increasing pulse-on time from 2 - 64 μs at fixed current of 10 A. Predictions for heat transfer and the cooling of melt pools, arising from single spark events, compared well with experimental observations for the development of these TiC/Fe cermet microstructures. The cooling phase had two distinct stages, with initial rapid non-uniform cooling within the first ~ 10 - 20 μs leading up to the onset of TiC crystallisation, followed by a more uniform stage of heat loss up to ~ 100 μs, leading up to the onset of Fe matrix solidification. The tribological behaviours of TiC/Fe ED cermet coatings on both HSS and 304-SS substrates were investigated, with reference Cu EDM surfaces. The wear resistance of these cermet coatings, on both substrate types, yielded dry sliding wear resistances up to two orders of magnitude greater than that of the substrate. Further, EDC cermet coatings on HSS were typically 2 - 4 times more wear resistant, depending on loading, than those deposited on 304-SS, with wear performances reflecting the composite nature of the coatings coupled with the mechanical properties of the substrates. Laser surface treatments, used to improve the surface integrity of the as-deposited coatings, through the elimination of cracks and porosity, acted to increase the wear rate for all samples, with the exception of coatings on HSS under conditions of high loading. The general increase in wear rate was attributed to a significant reduction in the proportion of TiC within the ED coatings, after laser treatment, combined with an increase in grain size; whilst improvements to the wear performance of laser treated, cermet coated HSS, under high loading, was attributed to the avoidance of an abrasive wear mechanism.

For the past decades, one of the major trends in industry has been micro-product manufacturing. Micro-parts are in high demand in many industries, including medical devices, electronics and automotive applications. The challenge in manufacturing micro-products is to achieve excellent surface quality in parts with sub-micron tolerances, whilst also maintaining low production costs. Precision can be established based on parameters such as linear and dynamic stability, as well as process repeatability. In micro-cutting, stability is influenced by variations of operating parameters which are considered constant in regular cutting. Such variations have been found in literature for shear angles and cutting forces as a result of the material anisotropy of single crystals. Models and experimental work for cutting force variation due to crystallographic orientation have been previously developed. However, the effects of the cutting force variation have not been sufficiently understood. The aim of the current research is to improve micro-cutting precision based on crystallographic anisotropy models. This thesis achieves four objectives that contribute to a new understanding of micro-cutting by investigating linear and dynamic stability, and repeatability in single crystal investigations. The first objective of this study has been to provide a better understanding of linear stability based on single crystal analytical models. Tool deflection and slope are modelled for the first time due to their proportionality with the cutting force. It is found that tool deflection varies by a factor of two for some crystallographic directions, negatively influencing the stability of the tool path. Cutting forces are also affected by the variation of tool deflection by a six Newtons difference. By providing this new tool deflection model, linear stability understanding is improved for cutting of single crystal materials. The second objective has been to experimentally validate cutting force variation in single grain cutting, and to provide a comparison with multigrain results. Previous studies have investigated either turning, either orthogonal cutting, but they have not considered the evolution of the tangential and radial components of the cutting force during a 360° workpiece rotation. This is critical in order to assess crystallographic anisotropy effects on stability and material deformation mechanisms. The current research has analysed both cutting force components, which enable new models to be developed. The radial cutting force has been successfully found to validate the force profile in the anisotropic analytical model. The third objective has been the development of new, single grain-specific cutting stability models. Classic stability analysis has been extended to include for the first time the variation of the cutting force and shear angle. The new models generate levels of critical depth of cut which vary widely from classic stability values, by 45% in analytically-based analysis and 70% in empirically-determined values. Based on this new knowledge, recommendations of new stability limits are made for manufacturers, in the direction of improving micro-cutting dynamic stability. The final objective of this research has been to provide a new and comprehensive understanding of material deformation mechanisms, due to single crystal cutting effects on surface quality and repeatability of results. Material phenomena analysis is provided for chip formation, burr and ploughing formation, and dimensional accuracy of machined features. Different chip morphologies are characterised for the first time and correlated with anisotropic models. Based on chip typology, chips can be classified as desirable, acceptable or undesirable in cutting. The results show that for a third of the overall number of chips, the morphology is unsuitable for cutting operations. Burr formation has been identified to occur by a four-peak repeatability, which matches the crystallographic anisotropy repeatability; a correlation between chip and burr generating mechanisms is established for 79% of results. In terms of dimensional accuracy, channel width has been analysed. A four-peak pattern and 1.43 times channel dimension variation is found. The chip, burr and dimensional accuracy findings provide an improved understanding of surface quality parameters and repeatability. Based on these new empirical findings, the manufacturing process parameters can be adjusted for optimal micro-cutting. In summary, the research presented in this thesis has investigated the effects of material microstructure properties on micro-cutting precision by developing new models for linear and dynamic stability. For the first time, the correlation between crystallographic anisotropy and surface quality, dimensional accuracy and repeatability have been assessed. These analyses contribute towards an improved understanding of material microstructure effects on micro-cutting precision, and have enabled the development of recommendations to improve micro-manufacturing results.

A sample of soil under external loads shows nonlinear behaviour. These external loads are propagated through grain-to-grain contacts. Consequently, the grains are being subjected to both tensile and compressive stresses according to their shape, position, and number of contacts. Thus, the nonlinear mechanical behaviour of soil may be described by investigating inter-particle stress transmission. The direct measurement of stress is a challenging task, both experimentally and numerically. In this study, stress-transmitting grains in a sand specimen are identified using an image-based approach. The methodology consists of measuring the geometrical data of the individual grains and following their evolution. On the numerical side, a more realistic description of soil behaviour is provided by developing a computational approach that quantifies internal stresses in each individual grain, termed micro Finite Element (μFE) model. The fabric of a natural sand obtained from the micro computed tomography (μCT) is virtualised to simulate the mechanical response of the material. The grain-to-grain interactions under loading are modelled in a framework of combined discrete-finite element method. Each individual grain is represented by a collection of nodes and elements and modelled as a continuum body that can deform according to a prescribed constitutive properties with appropriate friction contact conditions. The insights that can be gained into the stress transmission mechanisms and yield initiation within the grains are shown in a case study of an intact sand subjected to 1D compression. This includes stress and displacement field, inertia tensor, and active contact area. The contact behaviour used in the model is validated against existing theories for a single sphere and an assembly of spheres under triaxial loading. Then, single grain tests are conducted experimentally and numerically in order to better understand the influence of grain morphology on stress transmission. This study shows the strong dependency of contact behaviour on grain morphology. In addition, the effect of surface roughness is investigated showing the role of asperity abrasion under low normal loading. The evaluation of the μFE model has yielded results that compare well to experimental data obtained from a triaxial test in a μCT scanner. The stress field within each grain in the granular media is studied, contributing new insights beyond the commonly reported force chains. The ‘stress chain’ concept is considered as an alternative way to reflect grain breakage that may initiate on the weak force network and compromise the stability of the assembly. It is thus suggested that the ‘stress chain’ concept can be richer than ‘force chain’ and contains information about grain shape, mechanical properties and local fabric.

Vibration-based structural health monitoring (VSHM) is an automated method for assessing the integrity and performance of dynamically excited structures through processing of structural vibration response signals acquired by arrays of sensors. From a technological viewpoint, wireless sensor networks (WSNs) offer less obtrusive, more economical, and rapid VSHM deployments in civil structures compared to their tethered counterparts, especially in monitoring large-scale and geometrically complex structures. However, WSNs are constrained by certain practical issues related to local power supply at sensors and restrictions to the amount of wirelessly transmitted data due to increased power consumptions and bandwidth limitations in wireless communications. The primary objective of this thesis is to resolve the above issues by considering sub-Nyquist data acquisition and processing techniques that involve simultaneous signal acquisition and compression before transmission. This drastically reduces the sampling and transmission requirements leading to reduced power consumptions up to 85-90% compared to conventional approaches at Nyquist rate. Within this context, the current state-of-the-art VSHM approaches exploits the theory of compressive sensing (CS) to acquire structural responses at non-uniform random sub-Nyquist sampling schemes. By exploiting the sparse structure of the analysed signals in a known vector basis (i.e., non-zero signal coefficients), the original time-domain signals are reconstructed at the uniform Nyquist grid by solving an underdetermined optimisation problem subject to signal sparsity constraints. However, the CS sparse recovery is a computationally intensive problem that strongly depends on and is limited by the sparsity attributes of the measured signals on a pre-defined expansion basis. This sparsity information, though, is unknown in real-time VSHM deployments while it is adversely affected by noisy environments encountered in practice. To efficiently address the above limitations encountered in CS-based VSHM methods, this research study proposes three alternative approaches for energy-efficient VSHM using compressed structural response signals under ambient vibrations. The first approach aims to enhance the sparsity information of vibrating structural responses by considering their representation on the wavelet transform domain using various oscillatory functions with different frequency domain attributes. In this respect, a novel data-driven damage detection algorithm is developed herein, emerged as a fusion of the CS framework with the Relative Wavelet Entropy (RWE) damage index. By processing sparse signal coefficients on the harmonic wavelet transform for two comparative structural states (i.e., damage versus healthy state), CS-based RWE damage indices are retrieved from a significantly reduced number of wavelet coefficients without reconstructing structural responses in time-domain. The second approach involves a novel signal-agnostic sub-Nyquist spectral estimation method free from sparsity constraints, which is proposed herein as a viable alternative for power-efficient WSNs in VSHM applications. The developed method relies on Power Spectrum Blind Sampling (PSBS) techniques together with a deterministic multi-coset sampling pattern, capable to acquire stationary structural responses at sub-Nyquist rates without imposing sparsity conditions. Based on a network of wireless sensors operating on the same sampling pattern, auto/cross power-spectral density estimates are computed directly from compressed data by solving an overdetermined optimisation problem; thus, by-passing the computationally intensive signal reconstruction operations in time-domain. This innovative approach can be fused with standard operational modal analysis algorithms to estimate the inherent resonant frequencies and modal deflected shapes of structures under low-amplitude ambient vibrations with the minimum power, computational and memory requirements at the sensor, while outperforming pertinent CS-based approaches. Based on the extracted modal in formation, numerous data-driven damage detection strategies can be further employed to evaluate the condition of the monitored structures. The third approach of this thesis proposes a noise-immune damage detection method capable to capture small shifts in structural natural frequencies before and after a seismic event of low intensity using compressed acceleration data contaminated with broadband noise. This novel approach relies on a recently established sub-Nyquist pseudo-spectral estimation method which combines the deterministic co-prime sub-Nyquist sampling technique with the multiple signal classification (MUSIC) pseudo-spectrum estimator. This is also a signal-agnostic and signal reconstruction-free method that treats structural response signals as wide-sense stationary stochastic processes to retrieve, with very high resolution, auto-power spectral densities and structural natural frequency estimates directly from compressed data while filtering out additive broadband noise.

Biometric verification is the process of authenticating a person‟s identity using his/her physiological and behavioural characteristics. It is well-known that multimodal biometric systems can further improve the authentication accuracy by combining information from multiple biometric traits at various levels, namely sensor, feature, match score and decision levels. Fusion at match score level is generally preferred due to the trade-off between information availability and fusion complexity. However, combining match scores poses a number of challenges, when treated as a two-class classification problem due to the highly imbalanced class distributions. Most conventional classifiers assume equally balanced classes. They do not work well when samples of one class vastly outnumber the samples of the other class. These challenges become even more significant, when the fusion is based on user-specific processing due to the limited availability of the genuine samples per user. This thesis aims at exploring the paradigm of one-class classification to advance the classification performance of imbalanced biometric data sets. The contributions of the research can be enumerated as follows. Firstly, a thorough investigation of the various one-class classifiers, including Gaussian Mixture Model, k-Nearest Neighbour, K-means clustering and Support Vector Data Description, has been provided. These classifiers are applied in learning the user-specific and user-independent descriptions for the biometric decision inference. It is demonstrated that the one-class classifiers are particularly useful in handling the imbalanced learning problem in multimodal biometric authentication. User-specific approach is a better alternative with respect to user-independent counterpart because it is able to overcome the so-called within-class sub-concepts problem, which arises very often in multimodal biometric systems due to the existence of user variation. Secondly, a novel adapted score fusion scheme that consists of one-class classifiers and is trained using both the genuine user and impostor samples has been proposed. This method also replaces user-independent by user-specific description to learn the characteristics of the impostor class, and thus, reducing the degree of imbalanced proportion of data for different classes. Extensive experiments are conducted on the BioSecure DS2 and XM2VTS databases to illustrate the potential of the proposed adapted score fusion scheme, which provides a relative improvement in terms of Equal Error Rate of 32% and 20% as compared to the standard sum of scores and likelihood ratio based score fusion, respectively. Thirdly, a hybrid boosting algorithm, called r-ABOC has been developed, which is capable of exploiting the natural capabilities of both the well-known Real AdaBoost and one-class classification to further improve the system performance without causing overfitting. However, unlike the conventional Real AdaBoost, the individual classifiers in the proposed schema are trained on the same data set, but with different parameter choices. This does not only generate a high diversity, which is vital to the success of r-ABOC, but also reduces the number of user-specified parameters. A comprehensive empirical study using the BioSecure DS2 and XM2VTS databases demonstrates that r-ABOC may achieve a performance gain in terms of Half Total Error Rate of up to 28% with respect to other state-of-the-art biometric score fusion techniques. Finally, a Robust Imputation based on Group Method of Data Handling (RIBG) has been proposed to handle the missing data problem in the BioSecure DS2 database. RIBG is able to provide accurate predictions of incomplete score vectors. It is observed to achieve a better performance with respect to the state-of-the-art imputation techniques, including mean, median and k-NN imputations. An important feature of RIBG is that it does not require any parameter fine-tuning, and hence, is amendable to immediate applications.

In all fields, fundamental and applied research seek to produce experimental measurements without causing interferences to the process being observed. This capability is of paramount importance, since small perturbations of the phenomenon can alter it to the point of producing biased or even incorrect results. Xray techniques, based on synchrotron or laboratory X-ray sources, have attracted the attention of the research and industrial R&D community thanks to their characteristic of having little to no detectable influence on the subject under study. Moreover, if declined as tomography, this technique can provide localized full volume information at the micrometre scale, from which arbitrary shaped geometries and material densities can be deduced. During this thesis an X-ray microtomography instrument, based on a laboratory X-ray source, has been exploited to gain three main objectives. The first one is the analysis of how a liquid drop, of water or glycol, adapts its shape to reach an equilibrium state when gently deposed on a flat or patterned surface. So far this has been done using 2D techniques but introducing the knowledge of the third dimension and being able to see the drop shape even in not optically accessible locations, opens new possibilities to better understand the physics that regulate it. The second one is the reconstruction of the internal geometries of automotive diesel injectors with high resolution to detect and highlight differences between nominal and real geometries, key information to produce more realistic CFD simulations of the flow inside production grade injectors geometries. A scaled -up model made of PEEK was also studied, producing successive tomographies, to detect small geometrical changes induced by part usage, giving an in-depth view of the locations more prone to be damaged by cavitation flow. The third one is the study of a multiphase flow inside the same scaled-up model injection channel with flowing conditions exhibiting cavitation. The geometry of the non-axisymmetric model mimics the flow pattern of a real diesel injection channel and automotive grade diesel was consequently selected as fluid. Understanding the dependence of cavitation development on flow characteristics in a three-dimensional way, through the determination of the localized void fraction of the multiphase flow, can lead to improvements in the knowledge of such a phenomenon that can guide the design of future fuel injection equipment.

This study is inspired by a previous research of market potential identification for small scale solar power generator by David Sanchez. Sanchez et al’s model includes 5 factors’ analysis: Solar Irradiation (DNI), Demand, Grid, Social-Policy and Risk. Among these 5 factors, the Social-Policy factor includes the analysis of the policy of renewable energy and economy variation in EU countries as well as the energy import rate for 22 candidate countries. The potential problems for this Social-Policy factor model are: 1. This model overlooks the regional diversity on policy and economy situation in big countries, such as China. 2. This model analyses the policies for renewable energy in EU countries, however, it lacks specific policy information for solar power 3. The energy import rate cannot reflect the whole picture of other energies’ interference, especially in a country with sufficient local energy resources. Therefore, the aim of this study is to modify the model for Social-Political factor in Market Potentials Identification study and prove the market potential regional variety with this factor. This study also uses China as a case study in modifying the Social-Policy factor in the solar market potential identification study from Sánchez et al. and then identify the factor of social, economy and policy in different province in China. Factor ‘social, economy and policy’ (Fs) includes 4 sub-factors: Energy Mix Factor, Economic Factor (GDP &GDP growth rate), Policy factor (Local policy in solar power) and Solar increase trend factor. Through this study, it will be proved that there is difference for the market potential for China in each province. As a result, for big countries like China, the regional analysis needs to be applied on market potential identification.

The research conducted concerns the application of compensation grouting, particularly compaction grouting, as a method to reduce and control the ground movements generated in the soil by a deep retained excavation in firm to stiff clays. Compaction grouting involves the injection of grout into the soil to create a spherical or cylindrical grout bulb. This research investigates the effectiveness and limitations of the method to provide a preliminary understanding of the influence of the grouting volume, timing and position on the vertical settlements at the retained surface and horizontal displacements of the wall relative to the behaviour observed from the corresponding scenario in which only excavation occurs. Experimental data were obtained from a series of 10 successful centrifuge model tests undertaken at 100 g. The plane strain models consisted of a pre-formed 12 m deep (at prototype scale) retained excavation temporarily supported by the pressure of a dense fluid acting against the wall and formation surface and a relatively flexible retaining wall propped at the top. The dense fluid was removed and the subsequent soil movements at the retained surface, wall and the formation level were measured, using a combination of transducers and analysis of digital images taken of targets embedded in the front face of the model and wall. Three reference tests were conducted to establish the magnitude and pattern of soil and wall displacements generated by excavation alone. Idealised compaction grouting was modelled simultaneously with excavation in the remaining tests with the injection of ‘grout’ (water) into sealed latex tubes (supported by a perforated Nylon tube), inserted in the soil behind the excavation. The start of injection relative to the timing of the excavation varied amongst the tests. Grouting was continued until positive compensation of the local surface settlement was noted or significant horizontal displacements of the wall were observed. The tests showed that there appears to be no distinct relationship between the grout volume and the displacements at the retained surface above the injection and at a wall depth of 0.75 times the excavation depth, H due to injection. However, it was seen that for injections below a depth of 0.25H different critical volumes existed beyond which a positive compensation of the retained surface deteriorated or negative compensation increased at a greater rate. This was also reflected in the wall behaviour. The different injection initiation times showed that greater positive compensation effects could be achieved with injections up to a depth of 0.5H when conducted during the excavation, rather than in the period after. Timing had no influence on injections below this depth. The influence of injection timing was found to be secondary to the injection position. A linear relationship between the depth of injection and either positively or negatively compensated settlements was noted from the tests. Positive compensation of the ground surface is possible for injections conducted above a depth of 0.5H. However, below this depth a significant negative compensation effect on surface settlements and horizontal wall movements was noted regardless of timing or volume. Greater positive compensation effects and reduced negative effects on the wall were noted with increasing distance from the wall. Regions behind the wall have been identified where grouting provides positive compensation of the surface with minimal influence on the wall and where only negative effects are observed at both the surface and wall.

This research concerns the influence of a range of construction methods, acting at or below excavation formation level, on ground movements of the retained surface attributed to a 12m deep excavation in very soft to soft soil. Movements around excavations arise as a consequence of the removal of soil and lateral wall deformations. The work examined the behaviour of excavations that were supported by a high stiffness embedded retaining wall whilst modelling a variety of construction techniques. Four distinct construction methods were modelled which could be regarded as surcharging the formation level or stiffening the ground below excavation formation level. The specific techniques that were explored include underwater excavations, bermed excavations, deep soil mixing and double walled excavations. This study aimed to determine the efficiency of these construction measures on reducing the magnitude and extent of displacements occurring behind the retaining wall. Experimental data were obtained from twenty-two plane strain centrifuge model tests undertaken at 160g. The geometry of the model comprised a pre-formed excavation where the retaining wall was laterally supported by a continuous prop acting over the majority of the height of the wall and the excavation formation level was surcharged by a pressurised rubber bag. Pressure in the bag at formation level was reduced at a constant rate to simulate the stress change caused by the excavation process. Vertical movements at the retained ground surface were measured using displacement transducers whilst subsurface deformations elsewhere in the model were determined from the analysis of digital images captured by cameras viewing the front of the model through a Perspex window. The magnitude and extent of movements were quantified and the general patterns of ground deformation were identified for the construction methods implemented. A series of reference tests were conducted to provide a baseline against which modified excavation tests were compared. The stiff wall and continuous prop supporting the retaining wall ensured that the reference tests quantified the magnitude of displacements at the retained surface arising simply as a result of heave at the formation level. The main test series investigated a range of construction methods that aimed to surcharge or stiffen the formation level. Additional tests were also undertaken to evaluate the influence of wall embedment on the performance of the excavation system. Direct comparisons were also drawn between tests in an attempt to establish the significance of wall crest fixity on soil movements. The use of all of the special construction techniques investigated were shown to reduce the magnitude of vertical displacement behind the retaining wall and at the formation level; in addition to reducing horizontal displacements at the toe of the wall. Increasing the retaining wall embedment depth in the main test series generally reduced the magnitude of vertical settlement by a factor of two, however the effect was less pronounced in the reference tests. Improving the fixity of the crest of the wall delayed excavation collapse and, where additional support mechanisms were not employed, pinning the crest of the wall was shown to reduce maximum settlement in the reference test by a factor of three. Of the four supporting construction methods the underwater excavation was found to be the most effective owing to the reduced change in vertical stress during the simulated excavation. Various deep soil mixing geometries were modelled and similar excavation behaviour was observed, however deep soil mixing ground treatment extending to the toe of the retaining wall and across 2/3 of the excavation demonstrated a slight reduction in settlement. Similar behaviour was observed for double walled excavations. Combining underwater excavations with a double wall was shown to further reduce maximum settlements however little additional benefit was observed when performing an underwater excavation with a deep soil mixed soil layer at excavation formation level.

There is a growing interest for strengthening and upgrading existing concrete structures both in seismic and non-seismic regions due to their continuous deterioration as a result of aging, degradation induced environment conditions, inadequate maintenance, and the need to meet the modern codes (i.e. Eurocodes). Almost a decade ago, an innovative cement-based composite material, the so-called textile-reinforced mortar (TRM), was introduced in the field of structural retrofitting. TRM comprises high-strength fibres in form of textiles embedded into inorganic matrices such as cement-based mortars. TRM offers well-established advantages such as: fire resistance, low cost, air permeability, and ability to apply on wet surfaces and at ambient of low temperatures. It is well known that the effectiveness of any external strengthening system in increasing the flexural capacity of concrete members depends primarily on the bond between the strengthening material and member’s substrate. This PhD Thesis provides a comprehensive experimental study on the bond behaviour between TRM and concrete substrate and also provides a fundamental understanding of the flexural behaviour of RC beams strengthened with TRM. Firstly, the tensile properties of the textile reinforcement were determined through carrying out tensile tests on bare textiles, and TRM coupons. Secondly, the bond behaviour between TRM and concrete substrates both at ambient and, for the first time, at high temperature was extensively investigated. A total of 148 specimens (80 specimens tested at ambient temperature and 68 specimens tested at high temperatures) were, fabricated, and tested under double-lap shear. Parameters investigated at ambient temperature comprised: (a) the bond length; (b) the number of layers; (c) the concrete surface preparation; (d) the concrete compressive strength; (e) the textile surface condition; and (f) the anchorage through wrapping with TRM jackets. Whereas, the parameters examined at high temperatures included: (a) the strengthening systems (TRM versus FRP); (b) the level of temperature at which the specimens were exposed; (c) the number of FRP/TRM layers; and (d) the loading conditions. The results of ambient temperature tests indicated that the bond at the TRM-concrete interface is sensitive to parameters such as: the number of layers, the textile surface condition, and the anchorage through wrapping with TRM. On the other hand, the results of high temperature tests showed that TRM exhibited excellent bond performance with concrete (up to 400 0C) contrary to FRP which practically lost its bond with concrete at temperatures above the glass trainset temperature (Tg). The flexural strengthening of RC beams with TRM at ambient and for the first time at high temperature was also examined carrying out 32 half-scale beams. The examined parameters were: (a) the strengthening system (TRM versus FRP); (b) the number of layers; (c) the textile surface condition; (d) the textile fibre material; (e) the end-anchorage system of the external reinforcement; and (f) the textile geometry. The results of ambient temperature tests showed that TRM was effective in increasing the flexural capacity of RC beams but its effectiveness was sensitive to the number of layers. Furthermore, a simple formula used for predicting the mean FRP debonding stress was modified for predicting the TRM debonding stress based on the experiment data available. The results of high temperature tests showed that TRM maintained an average effectiveness of 55%, of its effectiveness at ambient temperature, contrary to FRP which has totally lost its effectiveness when subjected to high temperature. Finally, a stress reduction factor of TRM flexural effectiveness (compared to its ambient effectiveness) when subjected to high temperature was also proposed.