Laboratory Testing of Geomaterials

In the present study, the effect of waste ground rubber tire powder (WGRTP) modifier on various mechanical properties such as Marshall stability, flow, Marshall quotient (MQ), bulk specific gravity, air voids, voids filled with bitumen (VFB) and percent voids in compacted mineral aggregates (VMA) of asphalt mixture has been evaluated. The Marshall tests of the polymer modified asphalt mixture, prepared through dry process, indicated the optimum waste polymer modifier content to be 5% by weight of mix. The waste polymer modified asphalt mix containing 5% WGRTP showed considerable improvement in various mechanical properties of the mix compared to the conventional asphalt mixture. The appropriate amount of the added WGRTP was found to be 5% by weight of aggregate. This percentage results in the maximum level of stability. Keywords—Hot mix asphalt; Waste ground rubber tire powder; Dry process; Marshall test method

This paper presents a laboratory investigation of inherent anisotropic stiffness of natural Bangkok Clay under an isotropic stress condition over small-and intermediate-strain ranges. A triaxial apparatus, equipped with local strain measuring systems and bender element system, is employed. During isotropic consolidation, observations are made on smallstrain shear modulus (G vh and G hh) and intermediate-strain deformations (ε v and ε h), and the data are analyzed in terms of shear, bulk, and coupling moduli and their degradation. The results reveal that very soft to soft Bangkok Clay is relatively isotropic; however, medium Bangkok Clay shows more anisotropic characteristic at both small and intermediate strains. The anisotropic characteristics of medium Bangkok Clay are presented by having ε v /ε h = 1.5 and G hh /G vh = 1.18 during isotropic consolidation. Empirical equations to predict anisotropic in-situ small-strain shear moduli of Bangkok Clay are proposed. Alternative simplified empirical equations, as a function of water content, are also presented for practical use. The bulk and coupling moduli of Bangkok Clay are analyzed. The small-strain bulk and coupling moduli of very soft to soft clay are approximately constant with depth, whereas those of medium clay may be predicted from the initial void ratio. The ratio of small-strain coupling and bulk modulus (J/K) is approximately 6. In general, very soft to medium Bangkok Clay has a low degree of inherent stiffness anisotropy compared with that of other clays reported in the literature.

The theme worked entitled “Study of the impact of the use of the MAGA C212 grinding agent on the grinding process and the quality of cement at SCB-Cement BOUCLIER”. The methodology adopted consisted of conducting the tests on the mini-mill and extrapolating the results obtained to the main mill. The tests are summarized in the determination of the load of the mini-crusher with regard to the wear of the balls, the optimum flow rates of the mini-crusher without and with grinding agent using a test sample of cement or white sample, the optimum dosage of grinding agent for an optimum flow rate, the production of cement under the optimum conditions identified and the physico-chemical characterization of the cement produced, namely the loss on ignition and the percentage of SO3, the Specific Blaine Surface Area, the percentage of Refusal on 80 µm and 160 sieve µm, and the compressive strengths at 2, 7 and 28 days. Thus, thanks to the use of MAGA C212 as a grinding agent under production c...

Estimating the rate of settlement for foundation soils treated with vertical drains requires an understanding of the horizontal drainage behavior of the soil, because the time of consolidation settlement may be critical to the overall construction schedule and sequencing. This paper provides a case study comparison of the results of methodologies associated with obtaining design parameters for horizontal drainage for use with vertical drain design, including backcalculation of field settlement data, cone penetrometer testing for pore pressure dissipation, and laboratory Rowe cell testing, by means of the soft, cohesive Lake Bonneville soil deposits in Salt Lake City, Utah. Each of these methodologies has an inherent set of strengths and limitations that should be considered when vertical drains are being designed or time of consolidation settlement is being estimated. Backcalculation of field performance data is effective in identifying true in situ settlement behavior but is not always feasible. Rowe cell testing tends to provide values that more closely correspond with those obtained from backcalculation but is not often performed. Testing for pore pressure dissipation is the most used technique, but it can provide drainage values much higher than the other two methodologies.

This article experimentally evaluates the influence of the sample preparation method on the undrained monotonic and cyclic response of a saturated Malaysian kaolin. Two different sample preparation methods were adopted: slurry consolidation and moist compaction. The results of undrained monotonic triaxial tests showed the same critical state friction angle regardless of the sample preparation method and overconsolidation ratio. Under undrained cyclic loading, the well-known reduction in the number of cycles required to reach failure conditions with increasing cyclic stress ratios was evident regardless of the sample preparation method. However, important qualitative differences were observed depending on the sample preparation method, such as the degree of inherent anisotropy manifested in terms of the inclination of the effective stress paths, and the asymmetric vertical strain accumulation in the stressstrain space. The reasons for the observed differences in behavior are analyzed and discussed in the manuscript.

Introduction/framework/objectives
The use of pacemakers is not very prevalent, but almost all Occupational Health professionals already had some clients with thisequipment and, at times, had some doubts, especially in relation to situations in which there may be some discreet/moderate interference,as individuals are generally more alert to professional situations that can cause serious and/or consensual by the team that placed thedevice.

Methodology
This is a Bibliographic Review, initiated through a search carried out in April 2024 in the databases “CINALH plus with full text, Medlinewith full text, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Cochrane Database ofSystematic Reviews, Cochrane Methodology Register, Nursing and Allied Health Collection: comprehensive, MedicLatina and RCAAP”.

Content
The device consists of a pulse generator and one or two electrode cables; the first works energetically due to the built-in battery. Electricalcables are metallic wires covered with insulating material (silicone or polyurethane), with one or two metallic poles, with the endspositioned in the atrium and/or ventricle.
Technology has been progressively improved, so that they suffer less and less interference and are less relevant. The first devicesworked without interacting with the heart’s own rhythm. More recently, models have been developed with the ability to interact andcoordinate with the heart rhythm. The latter, in turn, are able to partially adjust to the metabolic demands of the moment (depending oninformation from movements, temperature, breathing and cardiac contractility, for example).
In terms of results, several possible classifications of different types of interference are also highlighted, with the respective severities andprobabilities of occurrence, as well as some specificities in relation to professional groups/tasks and also the measures taken by mostHealth and Safety teams should have on this topic.

Discussion and Conclusions
There are no absolute consensuses regarding what is safe and what is not; even so, most researchers agree that equipment is built in anincreasingly safer way in the face of domestic, social and work interference and that there are situations that almost certainly do not causeproblems and others that probably will, with another group of factors in an intermediate position.
It would be interesting to understand whether Portuguese companies are aware of the interference that may arise and are if they areconcerned with minimizing the danger, in the face of employees who identify themselves as carrying this type of equipment, in relation tohealthcare professionals, especially in positions with more relevant machinery/tasks in this context.

Paciente OG, 62 anos, com cardiomiopatia arritmogênica do ventrículo direito e taquicardia ventricular sustentada mal tolerada, portador de cardioversor desfi brilador implantável (CDI) de câmara única ventricular, retornou assintomático para avaliação de rotina. Não havia registro de arritmias sustentadas, e os limiares de estimulação e sensibilidade foram checados e estavam adequados (Fig. 1). No entanto, diante da telemetria do dispositivo, foi identifi cada uma falha de sensibilidade de uma extra-sístole ventricular (Fig. 2).Desse modo, diante da possibilidade de que essa falha pudesse gerar falha de detecção de uma taquicardia ventricular lenta (Fig. 3), o autoganho de sensibilidade do CDI foi modifi cado, com correção da falha de sensibilidade intermitente da extra-sístole.Figura 1. Medidas eletrofi siológicas do cardioversor-desfi brilador na avaliação inicial e ausência de arrtmias ventriculares documentadas.

Industrial (Inmetro) possui dois higrômetros de ponto de orvalho, do tipo espelho resfriado, que são utilizados como padrões de referência em umidade. Um higrômetro opera na faixa de -75ºC a +20ºC de temperatura de ponto de orvalho e o outro opera na faixa de -40ºC a +80ºC de temperatura de ponto de orvalho. O objetivo deste trabalho é apresentar a metodologia e os resultados de uma comparação realizada com os higrômetros de referência na faixa de -40ºC a +20ºC de temperatura de ponto de orvalho, faixa de sobreposição dos instrumentos.

Investigation of mechanical properties of masonry in historic buildings Mechanical properties of masonry from the historic Beylerbeyi Palace are analyzed in the paper. The indirect procedure was used as the owner did not allow usual testing. The mineralogical structure of the original mortar was initially determined. This was followed by preparation and laboratory testing of mortar and masonry samples. Mechanical properties obtained were corrected through dynamic identification so as to determine the real modulus of elasticity of the masonry. To this aim, an ambient vibration survey was performed, and the finite-element model of the palace was constructed and tuned. Finally, the strength parameters of the masonry were corrected.

Desde el ano 2009, el Servei Municipal de Patrimoni Cultural de Castalla desarrolla el Proyecto de recuperacion social del Conjunt Patrimonial del Castell de Castalla, para gestionar todo el patrimonio cultural y natural localizado en el cerro de la fortificacion. Una de sus lineas de trabajo primordiales es el analisis de los materiales y/o elementos ineditos hasta la fecha. En este sentido, juega un papel relevante la caracterizacion de los geomateriales del castillo. Esta linea de trabajo se desarrolla, desde 2015, con el Instituto Universitario de Materiales de la Universidad de Alicante. El presente estudio recoge los resultados obtenidos tras analizar muestras petreas, ceramicas, de morteros y revestimientos procedentes del Pati d�Armes. Un espacio andalusi y cristiano cuya cronologia va desde el siglo XI hasta el XVI. Se trata, ademas, de una novedosa contribucion para conocer los castillos valencianos, que complementa la tradicional investigacion arqueologica, arquitectonica...

The purpose of this research is to investigate the possibility of using waste Polyethylene Terephthalate as polymer additives in Bituminous binder. The characteristics of PET-modified binder obtained by fix mixing temperature, was investigated. The binders were prepared by mixing the PET in 2%, 4%, 6%, 8% and 10% (by the weight of optimum bitumen) with 80/100 penetration grade bitumen at temperature of 150 ºC. It may be inferred that PETmodified bituminous binders provide better resistance against permanent deformations due to their higher G*/sin d and . their higher softening point when compared to conventional binders. Using PET-modified binders also contribute to the recirculation of plastic waste, as well as to the protection of the environment.

Le présent projet porte sur une étude cartographique, pétrographique, minéralogique et géochimique des formations carbonatées du secteur de Bunkeya, situé à 250km au nord de la ville de Lubumbashi, dans la Province de Lualaba.
Les objectifs poursuivis dans l’élaboration de ce travail sont:
1) Établir une carte géologique détaillée du secteur étudié;
2) Déterminer les caractéristiques pétrographiques, minéralogiques et géochimiques de ces formations en s’intéressant aux roches calcaires susceptible d'être utilisées dans la fabrication du ciment.

The present technical note extends the previous work by the authors concerned with formulation of a constitutive model of elastoplastic response of sands (Superior sand model) and its application to the analyses of static liquefaction and instability states in triaxial compression and extension occurring in the undrained deformation of saturated granular materials. To account for time-dependent behavior and strain rate effects, an elastic, viscoplastic extension of the model to triaxial compression is proposed. The constitutive equations derived are used to predict the model response in different loading histories. In particular, strain rate and stress rate effects and undrained creep deformation for specified stress components are discussed in detail. Comparison of model predictions with available experimental data also is provided.Key words: saturated sand, constitutive model, elastic–viscoplastic behavior.

The response of the elastoplastic refined Superior sand constitutive model in undrained triaxial compression and extension tests is presented. The model is aimed at realistic simulation of liquefaction occurring in loose, saturated, granular materials under monotonic static loading. The yield surface introduced previously in the original Superior sand model is modified, and a non-associated flow rule is used. The isotropic hardening–softening is related to plastic deformation and distance to a reference yield curve. The refined model accounts for the different response of materials with different deposition densities. The model prediction of undrained triaxial compression and extension tests is compared with experimental results. The higher tendency for liquefaction response in extension is well described. Instability and phase-transformation states also are discussed, and the energy of liquefaction is quantified.Key words: static liquefaction, constitutive model, triaxial tests, li...

Dedico este trabalho primeiramente a Ti, Senhor meu Deus, como forma de obediência do seu desejo em minha vida. Agradeço ao meu orientador, Prof. José Carlos T. de B. Moraes, pela oportunidade e incentivo para realização desde trabalho, onde aprendi valores importantes como pesquisador, profissional e ser humano. Agradeço aos irmãos da Fé, pela paciência, compreensão e pela motivação dada para conclusão deste trabalho, pois não é possível estar presente em dois lugares ao mesmo tempo.

Dedico este trabalho primeiramente a Ti, Senhor meu Deus, como forma de obediência do seu desejo em minha vida. Agradeço ao meu orientador, Prof. José Carlos T. de B. Moraes, pela oportunidade e incentivo para realização desde trabalho, onde aprendi valores importantes como pesquisador, profissional e ser humano. Agradeço aos irmãos da Fé, pela paciência, compreensão e pela motivação dada para conclusão deste trabalho, pois não é possível estar presente em dois lugares ao mesmo tempo.

This research explores the results of the most common laboratory based indirect tension strength methods over the range of UCS strengths 0.1 MPa (cemented paste backfill) to 100 MPa (concrete). The accuracy of each of the methods is considered through a comparison with direct strength measurements completed on the same material. The results
of 241 individual tests suggest that the use of indirect tension methods to determine tension strength for all geo-material strength ranges may provide misleading results unless a correction-factor is applied. Correction factors that relate splitting and flexure results to direct tension results are provided. The correction factors are based on the characteristic UCS of the material. A comparison of the traditional empirical relationship to derive tension from UCS is presented and an updated relationship is proposed that is relevant over the UCS strength range 0.1–100 MPa.

The present study focuses on the importance of characterization of waste/post consumer polymers. In recent years sophisticated instrumental techniques played an important role in identification and characterization of polymers. Advances in computer techniques have been combined with analytical instruments to give analytical speed, resolution and minimal sample requirements unimagined a few years ago. The present study deals with the development of modified binder formulations from plastomer and elastomer type waste with an aim to minimize nonbiodegradable the post consumer polymer waste as well as environmental hazard, to meet this objective ten different samples have been picked up from several kinds of waste so as to cover different categories of polymeric waste from the domestic, industrial as well as medical waste. The samples were characterized using thermal characterization techniques like DSC (differential scanning calorimetry) and TGA (thermo gravimetric analysis). The melting and oxidative degradation behavior of polymer waste helped in sustainable waste management through developing the various modified bitumen formulations of commercial importance for highway industry. Modified binder formulations were initially characterized as per the relevant standards (code of practice) to ascertaining their suitability for above said application. The physical properties of modified binders are within the specified limits. Marshall stability, indirect tensile strength and creep modulus behaviour have been evaluated and discussed in this study to prove their dual benefits like waste minimization and suitability of such binders to be used for durable roads.

Colloidal silica (CS) grouting is a soil improvement technique introduced as an innovative remedial measure against seismic liquefaction. It consists of injecting soils with a time-hardening, nanosilica-based solution forming a silica gel among soil particles. This paper presents the results of an experimental study on the effects of an initial static shear stress on the behaviour of a cyclically loaded clean sand stabilised with 5% CS. Undrained cyclic triaxial tests were performed to analyse the cyclic response of loose untreated and stabilised sand specimens, isotropically or anisotropically consolidated at the same initial mean effective stress. The consolidation stage was used to provide insight on the compressibility of stabilised soil. Stress–strain behaviour, pore water pressure response and cyclic shear resistance were investigated. The results showed that: (i) stabilised sand exhibits higher compressibility than the untreated one during isotropic consolidation; (ii) cyclic...

The present study focuses on the importance of characterization of waste/post consumer polymers. In recent years sophisticated instrumental techniques played an important role in identification and characterization of polymers. Advances in computer techniques have been combined with analytical instruments to give analytical speed, resolution and minimal sample requirements unimagined a few years ago. The present study deals with the development of modified binder formulations from plastomer and elastomer type waste with an aim to minimize nonbiodegradable the post consumer polymer waste as well as environmental hazard, to meet this objective ten different samples have been picked up from several kinds of waste so as to cover different categories of polymeric waste from the domestic, industrial as well as medical waste. The samples were characterized using thermal characterization techniques like DSC (differential scanning calorimetry) and TGA (thermo gravimetric analysis). The melting and oxidative degradation behavior of polymer waste helped in sustainable waste management through developing the various modified bitumen formulations of commercial importance for highway industry. Modified binder formulations were initially characterized as per the relevant standards (code of practice) to ascertaining their suitability for above said application. The physical properties of modified binders are within the specified limits. Marshall stability, indirect tensile strength and creep modulus behaviour have been evaluated and discussed in this study to prove their dual benefits like waste minimization and suitability of such binders to be used for durable roads.

Shear bands and compaction bands have been obtained in Vosges Sandstone cylinders tested in the laboratory under confining pressures of 30 to160MPa. The specimens have been heavily instrumented under load and subjected to pre-and post-deformation ultrasonic and Xray tomography. The primary purpose of this study is to add a detailed knowledge of the small-scale development of permanent dilational and compactional strains to our understanding of the mechanisms operative in shear/compaction band development and associated mechanical behaviours. This will inform predictions of changed fault zone permeability and lead to better prediction of fault seal or fault leakage under subsurface conditions. Samples were strain gauged and acoustic emissions were also recorded for some samples. Most were subjected to pre-and post-deformation ultrasonic and Xray tomography. Provisional assessment of the shear bands shows that material has densified but the velocities have also decreased. Open fractures are also seen on the processed Xray images. The samples show bulk compaction. The compaction band studies are less advanced, with acoustic emissions showing development of separated discrete bands that may have a shear component. This is an ongoing study and more robust conclusions, including thin section work, are expected by the Meeting.

Thermal response test (TRT) is a common procedure for characterization of ground and borehole thermal properties needed for the design of a shallow geothermal heat pump system. In order to investigate and to develop more accurate and robust procedures for TRT control, modelling, and evaluation in semi-permeable soils with large water content, a pilot borehole heat exchanger was built in the main campus of the Universitat Politècnica de València. The present work shows the results of the experiments performed at the site, analysing the improvements that have been introduced both in the control of the heat injected during TRTs and in the methods to infer the ground thermal parameter. Three models are compared: two based on the infinite-line source theory and one based on the finite-line source scheme. The models were tested under two possible configurations of the equipment, i.e., with and without strict control of injected heat. Our results show the importance of heat injection control for a robust parameter assessment and the existence of additional heat transfer processes that the used models cannot completely characterize and that are related to the presence of significant groundwater flow at the site. In addition, our experience with the current installation and the knowledge about its strengths and weaknesses have allowed us to design a new and more complete test-site to help in the analysis and validation of new ground heat exchanger geometries.

Abstract: Shear strength is the basic strength properties of soil which controls the stability of a soil mass under loads. The shear strength of soil helps to design the foundation of all the civil engineering structures, stability of slopes, earth retaining walls, embankments, man-made excavation etc. All the problems of soil engineering are related in one way or the other with shear strength of the soil. The triaxial shear test is one of the precise methods to determine the shear strength of the soil. Here the loading is more often triaxial than biaxial which simulates, the field loading. In field saturation level of soil may vary and depends upon climatic condition, drainage condition, porosity, density of particle etc., which may affect the shear strength of soils. The shear strength parameters of partially saturated to nearly saturated compacted soils under varying degree of initial saturation, S (%) were determined through triaxial shear test. In doing so consolidated undraine...

Numerous correlations have been developed in the literature relating the compression index Cc of soft soils to simple index properties that serve as a useful reality check on oedometer test results. However, many of these empirical correlations are specific to soils of a certain geographic region and/or geological origin and therefore may not be applicable in other contexts. Compression index data and corresponding index properties, specific to a good geographic spread of Irish soft soil sites, have been compiled in this paper. Of all the forms of correlation considered, the relationship between compression ratio Cc and the natural water content is the most fruitful in terms of allowing preliminary predictions of compression index to be made.

Understanding how forces propagate through granular media is broadly relevant in acoustic and non-acoustic warfare applications. For example, sediment type can impact acoustic propagation during bottom bounce events that undersea assets use for navigation. There is not yet a complete theory of force propagation in granular media due to several nonlinearities, like friction and Hertzian contact interactions. Of particular interest is the crossover region between linear and nonlinear regimes, where the propagating stresses are comparable to the initial confining stress in the system, as well as the shock regime, where stresses greatly exceed confining prestress. Aiming to develop more complete theories of force propagation in these regimes, we perform experimental impact tests and analyze how forces propagate in two-dimensional, frictional granular media. Assemblies of photo elastic disks are subjected to a vertical confining stress and then impacted from the side by a pendulum. Both ...

The quantity of plastics used throughout the world is increasing every year. Municipal solid wastes (MSW), manufacturing processes and service industries produce a lot of waste plastic materials. The increasing awareness among consumers about the environment has contributed to the concerns over disposal of generated wastes. The growing number of plastic materials every year and limited landfill conditions causes many alternatives exist for the disposal of plastic waste. This paper provides a summary of the study on the utilization of polyethylene terephthalate (PET) in road construction. Data from researcher show that PET can improve some properties of modified asphalt mixture. Having considered the economic and environmental prudent angles, utilization of PET as an additive to asphalt mixture is suitable to be used for road pavement.

The present study focuses on the importance of characterization of waste/post consumer polymers. In recent years sophisticated instrumental techniques played an important role in identification and characterization of polymers. Advances in computer techniques have been combined with analytical instruments to give analytical speed, resolution and minimal sample requirements unimagined a few years ago. The present study deals with the development of modified binder formulations from plastomer and elastomer type waste with an aim to minimize nonbiodegradable the post consumer polymer waste as well as environmental hazard, to meet this objective ten different samples have been picked up from several kinds of waste so as to cover different categories of polymeric waste from the domestic, industrial as well as medical waste. The samples were characterized using thermal characterization techniques like DSC (differential scanning calorimetry) and TGA (thermo gravimetric analysis). The melting and oxidative degradation behavior of polymer waste helped in sustainable waste management through developing the various modified bitumen formulations of commercial importance for highway industry. Modified binder formulations were initially characterized as per the relevant standards (code of practice) to ascertaining their suitability for above said application. The physical properties of modified binders are within the specified limits. Marshall stability, indirect tensile strength and creep modulus behaviour have been evaluated and discussed in this study to prove their dual benefits like waste minimization and suitability of such binders to be used for durable roads.

Desde el ano 2009, el Servei Municipal de Patrimoni Cultural de Castalla desarrolla el Proyecto de recuperacion social del Conjunt Patrimonial del Castell de Castalla, para gestionar todo el patrimonio cultural y natural localizado en el cerro de la fortificacion. Una de sus lineas de trabajo primordiales es el analisis de los materiales y/o elementos ineditos hasta la fecha. En este sentido, juega un papel relevante la caracterizacion de los geomateriales del castillo. Esta linea de trabajo se desarrolla, desde 2015, con el Instituto Universitario de Materiales de la Universidad de Alicante. El presente estudio recoge los resultados obtenidos tras analizar muestras petreas, ceramicas, de morteros y revestimientos procedentes del Pati d�Armes. Un espacio andalusi y cristiano cuya cronologia va desde el siglo XI hasta el XVI. Se trata, ademas, de una novedosa contribucion para conocer los castillos valencianos, que complementa la tradicional investigacion arqueologica, arquitectonica...

This paper appraises the efficacy of using an analytical radial approximation for different thermal pile heat exchanger geometries. Unsteady radial heat-flow from fluid in a pipe set within a grouted borehole into the external ground is well-documented and can be solved analytically very rapidly using Laplace Transforms (Javed & Claesson, 2011). By comparing the radial model with finite-element simulations including explicit pile geometries, this paper provides a provisional analysis of the accuracy of this approach. Initial findings suggest that the radial model may provide an appropriate approximation to pile behaviour for certain pipe configurations, albeit with small 'mid-time' error.

The theme worked entitled “Study of the impact of the use of the MAGA C212 grinding agent on the grinding process and the quality of cement at SCB-Cement BOUCLIER”. The methodology adopted consisted of conducting the tests on the mini-mill and extrapolating the results obtained to the main mill. The tests are summarized in the determination of the load of the mini-crusher with regard to the wear of the balls, the optimum flow rates of the mini-crusher without and with grinding agent using a test sample of cement or white sample, the optimum dosage of grinding agent for an optimum flow rate, the production of cement under the optimum conditions identified and the physico-chemical characterization of the cement produced, namely the loss on ignition and the percentage of SO3, the Specific Blaine Surface Area, the percentage of Refusal on 80 µm and 160 sieve µm, and the compressive strengths at 2, 7 and 28 days. Thus, thanks to the use of MAGA C212 as a grinding agent under production c...

The paper presents the application of cement stabilization in the world and in our country. In addition to the literature review, basic physicalmechanical tests of the pavement base without the use of hydraulic binder and with the use of hydraulic binder with different percentages of participation (2, 4, and 6%) were given. The hydraulic binder of the manufacturer LaFarge HRB 12.5 was used as a binder, and the material on which this binder was tested is a clay material taken in the vicinity of Belgrade. Using this binder, it was concluded that any percentage of binder leads to significant improvement of the placenta and thus improves the load-bearing capacity of the pavement structure.

abstract: This work presents a new technique of image reconstruction by backscattering ultrasound tomography using radial images. It is based on the fact that a B mode echographic image, although incomplete or noisy, always contains more information than an image obtained by a projection technique. The new technique is to reconstruct a slice from radial echographic images of this same slice using classic echographic probes. The new method of "Moyennes Maximisees" {maximized-aver ages) combines the advantages of the method of "Maxima " and the method of "Moyenne " (average). This method was tested and applied in-vitro for the reconstruction of a slice of a fetus thigh. It offers a better image quality that increases with the number of radial images N, and enables to distinguish between various anatomical parts of the slice.

This paper presents the state parameter approach in constitutive modeling of soils within the framework of critical state soil mechanics. It has been shown that the state parameter, representing the difference between the current void ratio and the critical state void ratio corresponding to the current mean normal stress, is an effective parameter for describing the stress-strain behaviour of soils. Constitutive models with the state parameter as an internal variable are simple, however they can capture details in soil stress-strain response. Also, the state parameter is more appropriate parameter to represent the in-situ state of sand than relative density.

All modern bituminous surfacings whether they are laid on an airfield runway, a Formula 1 racing circuit or an urban motorway are all expected to perform. This expectation is affected by the cumulative effect of in-service stressing conditions such as increasing axle loads and tyre pressures or sideways movement. For the last 50 years the most common type of surfacing mixture for motorways and other main roads in the United Kingdom has been Hot Rolled Asphalt (HRA)(BSI, 1992). However, in recent years its expectation to perform has been severely tested due to successive hot summers and ever-increasing volumes of heavy trafficking. Permanent deformation is now a serious problem in the UK. Elsewhere in Europe, the problem of permanent deformation at high stress sites has existed for many years. In Germany, the use of studded tyres and high binder content surfacing mixes resulted in unacceptable levels of rutting. This resulted in the development of Stone Mastic Asphalt (SMA) in 1968. SMA was found to be resistant to permanent deformation because of a stable gap-graded aggregate skeleton structure with voids filled with a mastic mortar of bitumen / crushed sand and filler. This paper considers the effect of stress on the performance of differing types of mixes highlighting how SMA with cellulose fibre can be designed to meet the requirements of modern traffic in any high stress location.

Changes in temperature in clays of low permeability typically induce excess porewater pressures. In the context of geothermal piles this effect has typically been overlooked since most installations have occurred in soils with higher values of permeability. A parametric study is presented that solves the governing differential equations one dimensionally in a pile to study the influence of the various parameters: permeability and soil compressibility. A new shaft resistance reduction ratio has been also defined to illustrate the loss of bearing capacity. The study shows that when the value of permeability is 1E-11 m/s or lower, combined with a soil compressibility in excess of 2E10 Pa, the excess porewater pressures can be comparable to typical mobilised shaft resistances. The solution applied to the case of the Lambeth College, London, also provides a plausible explanation to the observed loss of shaft friction of the tested pile. Title: Effect of temperature induced excess porewater pressures on the shaft bearing capacity of geothermal piles

This paper shows the scientific possibilities of computed tomography for the study of concrete porosity. The enormous technological advances in computed tomography equipment used in materials research, with increasingly higher energy, better resolution and smaller pixel size will allow, in the near future, viewing pore sizes that are currently unthinkable, competing in resolution with the traditional techniques of mercury porosimetry and nitrogen adsorption. The challenge at that time (and to a lesser extent today) will be how to extract as much information as possible from the large amount of data provided by computed tomography equipment. In this article, through the study of six cubic specimens of 40 mm sides, different techniques of extraction and presentation of the information are shown, which help us to better understand the characterization of the morphology and distribution of the pores inside the concrete matrix. This information is essential to understand some of the macr...

The present research concerns a comparative analysis of the possible methods for estimating soft silty clay permeability to be used in the analysis of consolidation. For this purpose the consolidation response of a thick and homogeneous, instrumented soft silty clay deposit, on which an embankment was constructed, is back-analyzed using the finite-element method. To model the consolidation process, permeability data are carefully determined both from laboratory and in situ piezocone tests. One-dimensional and triaxial permeability test data are compared with the results of piezocone dissipation tests, the latter interpreted using four different solutions. The effects of anisotropy on permeability characteristics influencing the consolidation rate are also discussed.

Utilization of waste plastic in road making is nowadays considered as one of the positive options available to improve the quality of the bituminous mixture and also help to reduce plastic pollution in the environment. Plastic bottles are mainly composed of polyethylene terephthalate (PET). PET has many uses and is commonly used in processes such as packing and protecting. PET is considered a non-biodegradable material but it can also contribute to environmental problem when disposed in large quantities. Therefore, the growing quantities of waste should be reduced by reusing them for other useful applications. This research has examined the effects of using PET in a road making application by investigating its potential prospect in improving bituminous mixture properties. By using dry process, this research sought to determine the optimum percent of PET content that should be added to coat the aggregate and its effects on the properties of the bituminous mixture compared to those of...

One of the most fundamental concerns of teaching English as a foreign language (EFL) is to maximize the opportunities of learner-learner talk. Digitalized technological facilities can motivate committed teachers to adapt and adopt innovative ways of teaching oral skills. This article reports on an action research project implemented during one semester with a group of 14 willing Master students at the

For the most part, geotechnical engineers have been reluctant to modernize their approach to site investigation, analysis, and design, thereby conveying the notion that it is a mature discipline without need for updating. In reality, acceptance and utilization of new technologies to improve and enhance our capabilities are quite necessary. The problem is exacerbated by many universities with outdated curricula and textbooks that promote an earlier historical basis in soil mechanics, primarily from a laboratory stance, whereas the preponderance of real world data are from field tests, including in-situ and geophysical methods. Over the past century, our discipline evolved through a combination of theoretical, analytical, intuitive, empirical, statistical, and probabilistic solutions towards construction involving geomaterials. Yet, a number of outdated tests, correlations, and methodologies remain in use today due to an unwillingness to leave the old behind and move forward. A high-tech enhancement to geotechnics would certainly benefit the profession with respect to education, professional image, and matters of litigation.