Dissertations / Theses on the topic 'Engineering Properties'

This thesis explores the concept of metamaterials; a fairly recent concept in the literature which has attracted the attention of researchers due to their abnormal electromagnetic properties. We will particularly consider one dimensional version of a metamaterial made of layers. At the first glance, layered metamaterials are simply multi-layer thin films. The distinguishing feature of layered metamaterials is that they usually incorporate metals whereas most thin film structures in the past have only incorporated dielectrics. The immense interest in certain layered configurations of metals and dielectrics, particularly when the thicknesses are really thin compared to the wavelength, is due to their exhibition of seemingly counter-intuitive or impossible properties such as refraction to the same side of normal (negative refraction), evanescent wave amplification, or light focusing with a flat interface (flat lensing). The simple configuration of layered metamaterials and their interesting properties are the prime motivations of this work. In this thesis, we first start with a very generic electromagnetic description of the optical properties of layered structures. This general description appears to be novel due to presenting theory in new form. We use this understanding to explain how and why certain layered structures can exhibit negative refraction or flat lensing. This investigation has also led to several new predictions of new optical properties of layered metamaterial structures. We conclude this work by various experimental studies which validate the predictions of the work and also explore fabrication challenges in the making of layered metamaterials.
Applied Science, Faculty of
Engineering, School of (Okanagan)
Graduate

Amorphous and semi-crystalline poly(arylene ether sulfone) homo- and copolymers and related structures were systematically synthesized via nucleophilic, aromatic substitution reactions using the potassium carbonate/N-methylpyrrolidone synthesis route. In particular, deuterated poly(arylene ether sulfones) were synthesized in order to investigate molecular motion via deuterium NMR. The mechanical, dynamic mechanical and fracture properties of these materials were also examined. Polysulfones were characterized to be tough, ductile materials and it was found that polysulfone-poly(dimethylsiloxane) block copolymers blends with homopolysulfone serves to further increase their ductility as indicated by fracture toughness K_I,C measurements. In addition, it was demonstrated that functionalized polysulfone was an excellent thermoplastic modifier for brittle epoxy networks. The morphology and properties of these copolymers and copolymer-homopolymer blends were studied as a function of molecular weight and chemical structure. A number of techniques were utilized to elucidate the possible toughening mechanisms that are operative.
Ph. D.

In this thesis the properties of graphene and its few-layers are engineered to make them highly conductive. Two different approaches were implemented to achieve this goal. One approach was to increase the concentration of charge carriers by intercalation of acceptor FeCl3 molecules between graphene planes. This resulted in a highly conductive yet transparent material which can be useful for applications. Another approach was to increase the mobility of carriers by means of removing surface contamination in the current annealing process. Optimal annealing parameters were found and a reproducible cleaning method was suggested.

Prediction as a tool in engineering has been used in taking right judgement in many of the professional activities. This being the fact, the role and significance of prediction in geotechnical practice needs no emphasis. Bulk of all man made structures are either made of soil or are resting on natural soil, involving large quantities of soil. Thus, it is often necessary for the geotechnical engineer to quickly characterize the soil and determine their engineering properties, so as to assess the suitability of the soil for any specific purpose. Obtaining these properties requires undisturbed samples, which involves time and money, and also elaborate laboratory procedures. Thus, it is desirable to find simpler and quicker methods of testing, using the data of which the engineering properties can be predicted satisfactorily especially so, for preliminary design purposes. Most often this can be achieved from simple tests known as inferential tests, and the engineering properties namely, compressibility, swell/collapse, hydraulic conductivity, strength and compaction characteristics can be obtained from empirical/semi-empirical correlations. The index tests namely the Atterberg limits form the most important inferential soil tests with very wide universal acceptance. These tests are relatively simple to perform and have provided a basis for explaining most engineering properties of soils in geotechnical practice. In this direction, this investigation has been carried out to correlate the engineering properties with the simple index properties and their indices, namely, the liquid limit, plastic limit, shrinkage limit, plasticity index and shrinkage index (liquid limit - shrinkage limit). Any good correlation in the prediction of engineering properties with the index properties will enhance the use of simple test for prediction purposes. This thesis is an attempt towards this direction. It is often necessary to identify the basic mechanisms controlling the engineering properties from a micro-mechanistic point of view and correlate with the index properties, thereby facilitating prediction of engineering properties better. Though attempts have been made in the past to predict the engineering properties of soils from the index properties/indic­es, they are not quite satisfactory. This thesis is an attempt to predict the engineering properties of fine-grained soils from the index properties taking into consideration the mechanisms controlling them. Since, the index properties are used for prediction of engineering properties, the existing methods of determining the same have been examined carefully and critically. It's satisfactory determination is found important because other indices namely plasticity index, Ip and shrinkage index, Is = (wL - ws), are determined based on it. Also the liquid limit is one of the important and widely used parameter in various existing correlations. In this direction, two new methods of determining the liquid limit have been developed, namely (i) absorption water content and liquid limit of soils and (ii) liquid limit from equilibrium water content under Ko-stress. In the absorption water content method, the water absorbed by an oven dried soil pat at equilibrium gives a good correlation with the liquid limit of soils. Here, the water holding capacity at equilibrium goes well with the mechanism of liquid limit, which is also the water holding capacity of a soil at a particular small but measurable shear strength. A good relationship is found to exit between the absorption water content, wA and the liquid limit, wL, and it is given as : WA = 0.92 wL (i) In the second method, namely, the liquid limit from equilibrium water content under K0-stress, which is the equilibrium water content under a Ko stress of 0.9 kPa is found to be equal to the liquid limit obtained from the cone penetration method of determining the liquid limit It is found that this method of determining the liquid limit overcomes the limitations of the conventional methods of determining the liquid limit, also easy to determine with a simple apparatus and has good repeatability. Determination of plastic limit of the soils by the rolling thread method often poses a problem especially when the soil is less plastic. Hence, to overcome this problem, a new method has been proposed to predict the plasticity index in terms of the flow index. The relationship between the plasticity index and the flow index by the cone penetration cup method is found to be better than by the percussion cup method. Since, the cone penetration method of the liquid limit determination is more popular than the percussion cup method, the flow index from the cone method is recommended to determine the plasticity index from the correlation as given below: (/p)c = 0.74 Ifc (ii) Thus, the plastic limit can be determined with the plasticity index, thereby dispensing with the determination of plastic limit by the thread method. The determination of consolidation characteristics form an important aspect in the design of foundations and other earth retaining structures. The determination of consolidation characteristics namely the compression index, the coefficient of consolidation and the coefficient of secondary compression is time consuming. So, researchers have resorted to correlating the compressibility behaviour with simple index properties. While attempts have been made in the past to correlate the compressibility behaviour with various index properties individually, all the important properties affecting the compressibility behaviour has not been considered together in any single study to examine which of the index property/properties of the soils correlates better with the compressibility behaviour, especially with the same set of test results. Number of existing correlations with the liquid limit alone as a primary index property correlating with the compression index have limitations in that they do not consider the plasticity characteristics of the soils fully. The index parameter, shrinkage index, Is has a better correlation with the compression index, Cc and also the coefficient of volume change, mv than plasticity index. Coefficient of consolidation, Cv has also shown to correlate well with shrinkage index than the plasticity index. Even the coefficient of secondary compression, Cαε has shown to have a better correlation with shrinkage index than the plasticity index. However, liquid limit has a poor correlation with all the compressibility characteristics. The correlation of Cc and Cv with shrinkage index, Is is as given below: Cc = 0.007 (Is + 18) (iii) Cv = 3x10-2 (Is)-3.54 (in m2/sec) Further, to reduce the testing time of conventional consolidation test in order to obtain the compressibility characteristics, a new method known as rapid method of consolidation has been proposed, which is very effective in enormously reducing the time of consolidation without sacrificing the accuracy of the end results. The time required in the rapid method of consolidation testing could be as low as 4 to 5 hours to complete the whole test as compared to 1 to 2 weeks as the case may be by the conventional consolidation test. Using any curve fitting procedure the degree of consolidation, U for any pressure increment can be found out. Thus, the effective pressure at that stage can be calculated and further the pressure incremented without further delay. This procedure is repeated for every pressure increment with a load increment ratio of unity till the desired pressure level is reached. Even for a highly compressible soil like BC soil with a liquid limit of 73.5 %, the consolidation test could be completed within 5 hours by the rapid method, without any sacrifice of the accuracy of the results as compared to 7 days by the conventional method to reach a pressure of 800 kPa. Hydraulic conductivity is one of the basic engineering properties of soils. Of late hydraulic conductivity of fine-grained soils has assumed greater importance in waste disposal facilities. From the present investigation it is found that hydraulic conductivity with water for each pair of soils having nearly the same liquid limit but different plasticity properties is found to be vastly different, but found to correlate well with shrinkage index. A method to predict the hydraulic conductivity of fine -grained soils as a function of void ratio is proposed with the use of shrinkage index as given below: k = C [ ] (in m/sec) (v) 1 + e C = 2.5 x 10-4 (/s)-5.89 and n = 4 (vi) It has also been brought out that as the dielectric constant of the pore fluid decreases; there is a drastic increase in the intrinsic permeability of soil. These changes are attributed to the significant reduction in the thickness of diffuse double layer, which in turn is mainly dependent on the dielectric constant of the pore fluid. The quantification of the change in the hydraulic conductivity with the change in the pore fluids of extreme dielectric constant, i.e., from water to carbon tetrachloride could be expressed in terms of the volume of water held in the diffuse double layer and the same has a good correlation with shrinkage index. With the advancement in the knowledge of the engineering behaviour of fine-grained soils, there is an increasing trend toward larger involvement of fine-grained soils in earth structures and foundations. Though extensive work has been done in the past to understand the swelling behaviour of expansive soils and the mechanisms involved therein, it is yet not satisfactory. From the literature it can be seen that lot of work has been done to correlate the swell potential with various physical properties. The simple means of identifying the swelling type of soils is by means of free swell tests with the ratio of free swell with carbon tetrachloride to the free swell of water. The same has found to correlate well with the percent swell/collapse of the ten soils used in the present investigation. However, it was found that shrinkage index has a better correlation with the swell/collapse behaviour of fine-grained soils, compared to the liquid limit or the plasticity index. In this study, it is also shown that neither the liquid limit nor the plasticity index can qualitatively describe the swell/collapse behaviour of fine-grained soils. This has been attributed primarily to two different mechanisms governing montmorillonitic and kaolinitic soils separately. Even swelling pressure has shown to have a good correlation with shrinkage index. It is found that the compression index of the samples consolidated from the swollen condition correlates well with the shrinkage index. Laboratory determination of the compaction characteristics are very much important for use in earth work constructions. It is found that only the plastic limit bears a good correlation with the compaction characteristics namely optimum moisture content and maximum dry unit weight. This conclusion is also supported by the data from the literature. The correlations are given as: OMC = 0.92 wp (in percent) (viii) and ydmax = 0.23 (93.3 - wp) (inkN/m3) (ix) Liquid limit, plasticity index and shrinkage index do not bear any correlation with the compaction characteristics. It is quite possible that, the plastic limit, which is the optimum water content of a saturated soil at which it behaves as a plastic material, and thus can be moulded to any shape, thereby the soil can be compacted or moulded to the densest possible state at that water content. Hence, possibly the good correlation. A simple method to predict the compaction curve is proposed based on the plastic limit of the soils. Of all the important engineering properties, both volume change (compressibility and swelling) and hydraulic conductivity have good correlation with the shrinkage index. However, the compaction characteristics correlate well with the plastic limit. Herein, an hypothesis is proposed to possibly explain why shrinkage index has shown to be a better parameter to correlate with most of the engineering properties with the exception of the compaction characteristics. The liquid limit is a parameter which takes part of the plasticity characteristics of a soil. Recently it has been well brought out that shrinkage limit is primarily a function of how the varying grain sizes are distributed in a soil. Thus, shrinkage limit takes care of the gradation of the soil fractions in it. Thus, by considering the shrinkage index, which is the difference of the liquid limit water content on one end and shrinkage limit water content on the other end, the primary physical properties of the soils namely the plasticity and the grain size distribution are considered. This possibly explains the good correlation of shrinkage index with the engineering properties of fine-grained soils. However, compaction being a moulding of the soils into a compact state, it has a good correlation with the plastic limit, which is the optimum water content of a saturated soil at which it behaves as a plastic material, and thus can be moulded to any shape, thereby the soil can be compacted or moulded to the densest possible state at that water content. Hence, the good correlation. As the present investigation gives the correlative equations to predict the engineering properties of fine-grained soils from the appropriate index properties, which are obtained from simple and quick laboratory tests, it is hoped that this will go a long way in being a handy tool for a practicing geotechnical engineer in the preliminary assessment of fine-grained soils and thereby take appropriate judgement in various aspects of geotechnical constructions with it.

Prediction as a tool in engineering has been used in taking right judgement in many of the professional activities. This being the fact, the role and significance of prediction in geotechnical practice needs no emphasis. Bulk of all man made structures are either made of soil or are resting on natural soil, involving large quantities of soil. Thus, it is often necessary for the geotechnical engineer to quickly characterize the soil and determine their engineering properties, so as to assess the suitability of the soil for any specific purpose. Obtaining these properties requires undisturbed samples, which involves time and money, and also elaborate laboratory procedures. Thus, it is desirable to find simpler and quicker methods of testing, using the data of which the engineering properties can be predicted satisfactorily especially so, for preliminary design purposes. Most often this can be achieved from simple tests known as inferential tests, and the engineering properties namely, compressibility, swell/collapse, hydraulic conductivity, strength and compaction characteristics can be obtained from empirical/semi-empirical correlations. The index tests namely the Atterberg limits form the most important inferential soil tests with very wide universal acceptance. These tests are relatively simple to perform and have provided a basis for explaining most engineering properties of soils in geotechnical practice. In this direction, this investigation has been carried out to correlate the engineering properties with the simple index properties and their indices, namely, the liquid limit, plastic limit, shrinkage limit, plasticity index and shrinkage index (liquid limit - shrinkage limit). Any good correlation in the prediction of engineering properties with the index properties will enhance the use of simple test for prediction purposes. This thesis is an attempt towards this direction. It is often necessary to identify the basic mechanisms controlling the engineering properties from a micro-mechanistic point of view and correlate with the index properties, thereby facilitating prediction of engineering properties better. Though attempts have been made in the past to predict the engineering properties of soils from the index properties/indic­es, they are not quite satisfactory. This thesis is an attempt to predict the engineering properties of fine-grained soils from the index properties taking into consideration the mechanisms controlling them. Since, the index properties are used for prediction of engineering properties, the existing methods of determining the same have been examined carefully and critically. It's satisfactory determination is found important because other indices namely plasticity index, Ip and shrinkage index, Is = (wL - ws), are determined based on it. Also the liquid limit is one of the important and widely used parameter in various existing correlations. In this direction, two new methods of determining the liquid limit have been developed, namely (i) absorption water content and liquid limit of soils and (ii) liquid limit from equilibrium water content under Ko-stress. In the absorption water content method, the water absorbed by an oven dried soil pat at equilibrium gives a good correlation with the liquid limit of soils. Here, the water holding capacity at equilibrium goes well with the mechanism of liquid limit, which is also the water holding capacity of a soil at a particular small but measurable shear strength. A good relationship is found to exit between the absorption water content, wA and the liquid limit, wL, and it is given as : WA = 0.92 wL (i) In the second method, namely, the liquid limit from equilibrium water content under K0-stress, which is the equilibrium water content under a Ko stress of 0.9 kPa is found to be equal to the liquid limit obtained from the cone penetration method of determining the liquid limit It is found that this method of determining the liquid limit overcomes the limitations of the conventional methods of determining the liquid limit, also easy to determine with a simple apparatus and has good repeatability. Determination of plastic limit of the soils by the rolling thread method often poses a problem especially when the soil is less plastic. Hence, to overcome this problem, a new method has been proposed to predict the plasticity index in terms of the flow index. The relationship between the plasticity index and the flow index by the cone penetration cup method is found to be better than by the percussion cup method. Since, the cone penetration method of the liquid limit determination is more popular than the percussion cup method, the flow index from the cone method is recommended to determine the plasticity index from the correlation as given below: (/p)c = 0.74 Ifc (ii) Thus, the plastic limit can be determined with the plasticity index, thereby dispensing with the determination of plastic limit by the thread method. The determination of consolidation characteristics form an important aspect in the design of foundations and other earth retaining structures. The determination of consolidation characteristics namely the compression index, the coefficient of consolidation and the coefficient of secondary compression is time consuming. So, researchers have resorted to correlating the compressibility behaviour with simple index properties. While attempts have been made in the past to correlate the compressibility behaviour with various index properties individually, all the important properties affecting the compressibility behaviour has not been considered together in any single study to examine which of the index property/properties of the soils correlates better with the compressibility behaviour, especially with the same set of test results. Number of existing correlations with the liquid limit alone as a primary index property correlating with the compression index have limitations in that they do not consider the plasticity characteristics of the soils fully. The index parameter, shrinkage index, Is has a better correlation with the compression index, Cc and also the coefficient of volume change, mv than plasticity index. Coefficient of consolidation, Cv has also shown to correlate well with shrinkage index than the plasticity index. Even the coefficient of secondary compression, Cαε has shown to have a better correlation with shrinkage index than the plasticity index. However, liquid limit has a poor correlation with all the compressibility characteristics. The correlation of Cc and Cv with shrinkage index, Is is as given below: Cc = 0.007 (Is + 18) (iii) Cv = 3x10-2 (Is)-3.54 (in m2/sec) Further, to reduce the testing time of conventional consolidation test in order to obtain the compressibility characteristics, a new method known as rapid method of consolidation has been proposed, which is very effective in enormously reducing the time of consolidation without sacrificing the accuracy of the end results. The time required in the rapid method of consolidation testing could be as low as 4 to 5 hours to complete the whole test as compared to 1 to 2 weeks as the case may be by the conventional consolidation test. Using any curve fitting procedure the degree of consolidation, U for any pressure increment can be found out. Thus, the effective pressure at that stage can be calculated and further the pressure incremented without further delay. This procedure is repeated for every pressure increment with a load increment ratio of unity till the desired pressure level is reached. Even for a highly compressible soil like BC soil with a liquid limit of 73.5 %, the consolidation test could be completed within 5 hours by the rapid method, without any sacrifice of the accuracy of the results as compared to 7 days by the conventional method to reach a pressure of 800 kPa. Hydraulic conductivity is one of the basic engineering properties of soils. Of late hydraulic conductivity of fine-grained soils has assumed greater importance in waste disposal facilities. From the present investigation it is found that hydraulic conductivity with water for each pair of soils having nearly the same liquid limit but different plasticity properties is found to be vastly different, but found to correlate well with shrinkage index. A method to predict the hydraulic conductivity of fine -grained soils as a function of void ratio is proposed with the use of shrinkage index as given below: k = C [ ] (in m/sec) (v) 1 + e C = 2.5 x 10-4 (/s)-5.89 and n = 4 (vi) It has also been brought out that as the dielectric constant of the pore fluid decreases; there is a drastic increase in the intrinsic permeability of soil. These changes are attributed to the significant reduction in the thickness of diffuse double layer, which in turn is mainly dependent on the dielectric constant of the pore fluid. The quantification of the change in the hydraulic conductivity with the change in the pore fluids of extreme dielectric constant, i.e., from water to carbon tetrachloride could be expressed in terms of the volume of water held in the diffuse double layer and the same has a good correlation with shrinkage index. With the advancement in the knowledge of the engineering behaviour of fine-grained soils, there is an increasing trend toward larger involvement of fine-grained soils in earth structures and foundations. Though extensive work has been done in the past to understand the swelling behaviour of expansive soils and the mechanisms involved therein, it is yet not satisfactory. From the literature it can be seen that lot of work has been done to correlate the swell potential with various physical properties. The simple means of identifying the swelling type of soils is by means of free swell tests with the ratio of free swell with carbon tetrachloride to the free swell of water. The same has found to correlate well with the percent swell/collapse of the ten soils used in the present investigation. However, it was found that shrinkage index has a better correlation with the swell/collapse behaviour of fine-grained soils, compared to the liquid limit or the plasticity index. In this study, it is also shown that neither the liquid limit nor the plasticity index can qualitatively describe the swell/collapse behaviour of fine-grained soils. This has been attributed primarily to two different mechanisms governing montmorillonitic and kaolinitic soils separately. Even swelling pressure has shown to have a good correlation with shrinkage index. It is found that the compression index of the samples consolidated from the swollen condition correlates well with the shrinkage index. Laboratory determination of the compaction characteristics are very much important for use in earth work constructions. It is found that only the plastic limit bears a good correlation with the compaction characteristics namely optimum moisture content and maximum dry unit weight. This conclusion is also supported by the data from the literature. The correlations are given as: OMC = 0.92 wp (in percent) (viii) and ydmax = 0.23 (93.3 - wp) (inkN/m3) (ix) Liquid limit, plasticity index and shrinkage index do not bear any correlation with the compaction characteristics. It is quite possible that, the plastic limit, which is the optimum water content of a saturated soil at which it behaves as a plastic material, and thus can be moulded to any shape, thereby the soil can be compacted or moulded to the densest possible state at that water content. Hence, possibly the good correlation. A simple method to predict the compaction curve is proposed based on the plastic limit of the soils. Of all the important engineering properties, both volume change (compressibility and swelling) and hydraulic conductivity have good correlation with the shrinkage index. However, the compaction characteristics correlate well with the plastic limit. Herein, an hypothesis is proposed to possibly explain why shrinkage index has shown to be a better parameter to correlate with most of the engineering properties with the exception of the compaction characteristics. The liquid limit is a parameter which takes part of the plasticity characteristics of a soil. Recently it has been well brought out that shrinkage limit is primarily a function of how the varying grain sizes are distributed in a soil. Thus, shrinkage limit takes care of the gradation of the soil fractions in it. Thus, by considering the shrinkage index, which is the difference of the liquid limit water content on one end and shrinkage limit water content on the other end, the primary physical properties of the soils namely the plasticity and the grain size distribution are considered. This possibly explains the good correlation of shrinkage index with the engineering properties of fine-grained soils. However, compaction being a moulding of the soils into a compact state, it has a good correlation with the plastic limit, which is the optimum water content of a saturated soil at which it behaves as a plastic material, and thus can be moulded to any shape, thereby the soil can be compacted or moulded to the densest possible state at that water content. Hence, the good correlation. As the present investigation gives the correlative equations to predict the engineering properties of fine-grained soils from the appropriate index properties, which are obtained from simple and quick laboratory tests, it is hoped that this will go a long way in being a handy tool for a practicing geotechnical engineer in the preliminary assessment of fine-grained soils and thereby take appropriate judgement in various aspects of geotechnical constructions with it.

Gelfill (GF) is made of tailings, water, binder and chemical additives (Fillset, sodium silicate gel). The components of GF are combined and mixed on the surface and transported (by gravity and/or pumping) to the underground mine workings, where the GF can be used for both underground mine support and tailings storage. Thermal (T), hydraulic (H), and mechanical (M) properties are important performance criteria of GF. The understanding of these engineering properties and their evolution with time are still limited due to the fact that GF is a new cemented backfill material. In this thesis, the evolution of the thermal, hydraulic, mechanical, and microstructural properties of small GF samples are determined. Various binder contents of Portland cement type I (PCI) are used. The GF is cured for 3, 7, 28, 90, and 120 days. It is found that the thermal, hydraulic and mechanical properties are time-dependent or affected by the degree of binder hydration index. Furthermore, a relationship is found between the compressive strength and the saturated hydraulic conductivity of the GF samples. The unsaturated hydraulic properties of GF samples have also been investigated. The outcomes show that unsaturated hydraulic conductivity is influenced by the degree of binder hydration index and binder content, especially at low suction ranges. Simple functions are proposed to predict the evolution of air-entry values (AEVs), residual water content, and fitting parameters from the van Genuchten model with the degree of hydration index (α). Furthermore, two columns are built to simulate the coupled thermo-hydro-mechanical (THM) behaviour of GF under drained and undrained conditions. The obtained results from the GF columns are compared with the small samples. It is observed that the mechanical properties, hydraulic properties (suction and water content), and temperature development are strongly coupled. The magnitude of these THM coupling factors is affected by the size of the GF. The findings also show that the mechanical, hydraulic and thermal properties of the GF columns are different from samples cured in plastic moulds.

1.2 Objective This study investigated the effects of sulfate exposure on the mechanical properties of Portland cement concrete. Concrete specimens cast from mixtures composed of locally available aggregate and cement were exposed to a 10% (67,600 ppm) sodium sulfate solution for periods up to 2 years. During this exposure, the specimens were periodically tested for compressive strength, tensile strength, and dynamic modulus of elasticity to determine how the sulfate environment influenced the mechanical properties of concrete. 1.3 Scope This report presents a study intended to evaluate changes in mechanical properties of concrete deteriorating due to sulfate attack. Chapter 2 presents a literature review for sulfate attack on concrete. Mechanisms and characteristics of sulfate attack are explained, and previous works by other investigators are summarized to provide insight to the accelerated testing methods used in the current study. Chapter 3 explains the experimental procedures used in this study, the materials used in the study, the mixing procedure, and the testing procedures. Results obtained from the laboratory tests are presented and discussed in Chapter 4. Chapter 5 presents a summary of the study and the conclusions derived from the test results.
v, 120 leaves

Kyoto University (京都大学)
0048
新制・課程博士
博士(地球環境学)
甲第19387号
地環博第143号
新制||地環||29(附属図書館)
32401
新制||地環||29
京都大学大学院地球環境学舎環境マネジメント専攻
(主査)教授 勝見 武, 教授 高岡 昌輝, 准教授 乾 徹
学位規則第4条第1項該当

The facile synthesis of engineering thermoplastics enabled the development of structure-morphology-property relationships for a wide range of applications. Utilizing step-growth polymerization techniques, a myriad of reaction conditions probed various polymer families including polysulfones, polyesters, polyimides and polyureas. Copolymers ranging from random to segmented sequences provided insight into the influence of segment length on physical properties. Melting temperatures, glass transition temperatures, and mechanical properties responded systematically to segment length and morphology. Leveraging several complementary analytical techniques identified critical segment lengths required for phase separation and crystallization within these copolymers. Introduction of hydrogen bonding further complicated the interrelationships between thermal and mechanical properties, and possible co-crystallization between dissimilar segments occurred. Finally, branching out from linear copolymers to other topologies determined the influence of branch length on rheological and mechanical properties. The commercially-viable synthesis of these various thermoplastics further highlights the immediate impact on state-of-the-art materials, and the fundamental development described herein provides a road map for future development in this field.
Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.
Includes bibliographical references (p. 145-154).
Many applications demand materials with seemingly incompatible optical characteristics. For example, immersion photolithography is a resolution enhancing technique used to fabricate the ever-shrinking nanostructures in integrated circuits but requires a material that has-at the same time--a large index of refraction and negligible optical loss. Other applications require devices that have optical properties that seem exorbitant given the constraints posed by the geometry, materials, and desired performance of these devices. The superconducting nanowire single-photon detector (SNSPD) is one such device that, on the one hand, needs to absorb and detect single telecom-wavelength photons (A = 1.55 pm) with near-perfect efficiency, but on the other hand, has an absorber that is subwavelength in its thickness (A/390). For both cases, it is simply not enough to look for alternative materials with the desired optical properties, because the materials may not exist in nature. In fact, it has become necessary to engineer the optical properties of these devices and materials using other means. In this thesis, we have investigated how the optical properties of materials and devices can be engineered for specific applications. In the first half of the thesis, we focused on theoretical schemes that use subwave-length, resonant constituents to realize a material with interesting optical properties. We proposed a scheme that can achieve high index (n > 6) accompanied with optical gain for an implementation involving atomic vapors. We then explored the applicability of this high-index system to immersion lithography and found that optical gain is problematic. We solved the issue of optical gain by proposing a scheme where a mixture of resonant systems is used. We predicted that this system can yield a high refractive index, low refractive index, anomalous dispersion, or normal dispersion, all with optical transparency. In the second half, we studied the optical properties of SNSPDs through theoretical and experimental methods. In the study, we first constructed a numerical model that predicts the absorptance of our devices. We then fabricated SNSPDs with varying geometries and engineered a preprocessing-free proximity-effect correction technique to realize uniform linewidths. We then constructed an optical apparatus to measure the absorptance of our devices and showed that the devices are sensitive to the polarization of single photons.
by Vikas Anant.
Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.
Includes bibliographical references (leaves 287-292).
by Sergio Covarrubias Fernández.
M.S.

This thesis aims to measure the mechanical properties of ceramics on the microscale using microcantilever beams. Focussed Ion Beam milled triangular cross-sectional beams (approximately 3 x 5 x 20µm) were fractured using a nanoindenter to measure the Young’s modulus, fracture strength, and fracture toughness. By developing the technique with a sapphire bicrystal, it was found that the mechanical properties could be successfully ascertained if correction factors were used. Experiments and theoretical work showed that sapphire and polycrystalline alumina beams undergo moisture assisted sub-critical crack growth when tested in air. Whilst corrections for the Young’s modulus have been previously reported, this is the first reported attempt to correct for the notch tip residual stress and the first to consider sub-critical crack growth. Once these factors were characterised using the sapphire bicrystal, the technique was applied to a range of different ceramics, such as polycrystalline α-alumina and silicon nitride. These are the first reported direct measurements the grain boundary toughness of these ceramics using microcantilever beams. The grain boundary toughness was correlated with the macroscopic fracture properties and the characteristics of the ceramic (grain boundary composition, impurities, and fracture mode). Two grades of α-alumina were used and the macro- and micro-scale properties extensively compared. The damage evolution during uniaxial compression of alumina was investigated in depth, and compared to a previous reported microcrack evolution model using the measured grain boundary toughness. Investigation of whether deformation twins formed during loading was undertaken and the phenomenon was shown to not occur.

Cette thèse s’intéresse aux relations entre les caractéristiques du Caoutchouc Naturel, ses propriétés de mise en oeuvre et les propriétés mécaniques d’échantillons vulcanisés, en considérant une sélection de grades représentatifs. Des techniques de spectroscopie, physicochimiques et de rhéologie ont été utilisées, ainsi que des mesures de propriétés mécaniques sur des mélanges vulcanisés. Les résultats montrent que, telles quelles, les techniques spectroscopiques ne révèlent pratiquement aucune différence entre les divers grades étudiés. Cependant, en utilisant une technique de polarisation croisée de l’angle magique de spin 13C, on peut distinguer les composants mobiles et immobiles qui montrent des différences entre les grades. Les grades feuilles fumées (RSS) ont les taux de gel les plus élevés, en accord avec leur masse molaire, leur viscosité Mooney et leur module complexe. Parce qu’elle fournit des informations détaillées sur le comportement viscoélastique non-linéaire, la rhéométrie à Transformée de Fourier se révèle capable de discerner les différents grades étudiés. Par exemple, tous les grades présentent une région linéaire jusqu’environ 60% de déformation mais les échantillons de RSS montrent une non-linéarité intrinsèque (c. A. D. Induite par la structure du matériau) tandis que les grades à viscosité stabilisée sont extrinsèquement non-linéaire (nonlinéarité induite par la déformation), comme la plupart des polymères simples. Les effets de mastication ont été étudiés sur des échantillons de RSS3 et de SMR10CV60 et on a trouvé que les premiers requièrent plus d’énergie que les derniers. La viscosité Mooney et la masse molaire décroissent avec l’augmentation de l’énergie de mélangeage. Il apparaît que la mastication détruit le contenu en gel, de sorte que le module complexe diminue, de même que la sensibilité à l’histoire du cisaillement. Les mélanges chargés au noir de carbone avec les grades latex des champs (STR5L, RSS3 et RSS3E) ont des modules complexes plus élevés que les grades à viscosité stabilisée (OMNR, STR5CV60 et SMR10CV). Pour une même formule, mais des grades différents de caoutchouc naturel, les propriétés physiques des caoutchoucs vulcanisés ne montrent aucune différence significative
This thesis investigates the relationships between the characteristics of Natural Rubber, its processing properties and the mechanical properties of vulcanized specimens by using a selection of representative grades. Spectroscopic, physico-chemical and rheological techniques were used, as well as mechanical testing of vulcanized compounds. Results show that, as such, spectroscopic techniques are not able to reveal significant differences between the various investigated NR grades. However, by using 13C cross-polarization magic angle spinning (CP-MAS) technique, mobile and immobile components can be distinguished, so highlighting differences between grades. Ribbed Smoked Sheet (RSS) grades exhibit the highest gel content, in agreement with molecular weight, Mooney viscosity and complex modulus. Thanks to the very detailed information it provides regarding the nonlinear viscoelastic behavior, Fourier Transform rheometry is shown to clearly distinguish between the various NR grades. For instance all tested samples exhibit a linear region up to around 60% strain but RSS samples exhibit intrinsic nonlinearity (i. E. Morphology-induced) whilst viscosity stabilized grades show essentially extrinsic non-linearity (i. E. Strain-induced), like most simple polymers. Mastication effects on samples of RSS3 and SMR10CV60 were studied and the former were found to require higher mixing energy than the latter. Mooney viscosity and molecular weight decrease with increasing mixing energy. The mastication process appears to destroy the gel content of NR, so that the complex modulus is decreased as well as all strain history sensitivity. Carbon Black filled compounds with field latex grades (STR5L, RSS3 and RSS3E) are found to exhibit higher complex modulus than viscosity stabilized grades (OMNR, STR5CV60 and SMR10CV). Physical properties of cured rubber for the same formula but different rubber samples show no significant difference

Surfactant coated microbubbles are widely used as contrast agents (UCA) in medical ultrasound imaging, due to their high echogenicity and non-linear response to acoustic excitation. Controlling the stability of microbubbles in vivo represents a considerable challenge. Understanding the characteristics of the bubble surface and how they change with production method, composition and environment is key to addressing this problem. The aim of this thesis is to investigate viscosity, bubble dissolution, and acoustic response as functions of their composition, manufacturing method and environment. Bubbles were made using combinations of phospholipid and an emulsifier in different molar ratios. Adding the emulsifier decreased both the size and the surface viscosity of the bubbles and caused changes in the scattered pressure amplitude of bubbles under ultrasound. To increase microbubble stability, solid inorganic nanoparticles were adsorbed on to the microbubble surface. These particles behaved as Pickering stabilisers, and deterred Ostwald ripening. The nanoparticles also enhanced the nonlinear behaviour of bubbles at low acoustic pressures. Three manufacturing methods (sonication, cross-flow and flow focusing) were investigated in order to verify stability differences. Sonication produced bubbles with surface viscosities hundreds of centipoise greater than those produced by microfluidics. Both pressure amplitude and harmonic content for sonicated bubbles were found to be much larger due to a higher liposomal adhesion rate at the surface. Solution temperature and bubble age were also investigated. When the solutions were heated above the phospholipid gelling temperature, microfluidic bubbles showed an increased surface viscosity, due to increased liposome adhesion caused by the increased temperature. Bubble composition, manufacturing method and environment were found to vary the surface characteristics of the microbubbles. Further investigations into the affects of the filling gas, in vitro studies, and low temperature TEM characterisation should be conducted to produce a microbubble with the full range of desired characteristics.

碩士
國立成功大學
土木工程學系碩博士班
97
For the roadway of long span bridges, stiffened and lightweight orthotropic steel bridge deck could effectively resist loading and reduce self-loading. Also, steel deck has advantage of rapid- practicing construction and easy-controlling accuracy and precision. Guss asphalt (Guss) has a great compatibility against deformation, an excellent fatigue crack resistance and a fine water-proof property. Guss possesses fluid property in high temperature mixing so that Guss could completely combine with steel deck and be impervious to water. Steel deck is a low stiffness and relatively flexible structure; therefore repetitive deflection causes fatigue crack of Guss on the steel deck. Guss has high percentage mastic content, so the resistant ability almost depends on stiffness of Guss mastic. It is important that influence of aging and rutting for Guss. In this research, mixing design of Guss, simulating aging effect of Guss, engineering and fatigue properties of Guss were conducted. This research mainly concerned issue of rutting in high temperature and fatigue life of decision for Guss. The results indicate that mixing design of Guss were different optimum mastic content by aggregate of cold and hot feed bins, mastic content had prominent influence on fluid property and dynamic stability of Guss, increased ability of resistance to rutting by aging effect, but quality and durability of Guss decreased with aging time increased. Furthermore, performed under same temperature, frequency and strain controlled loading condition, these results of fatigue test indicate that, fatigue life of Guss were longer than modified III type asphalt dense mixtures and AC-20 asphalt dense mixtures. Failure criteria included the use of traditional fatigue life, stiffness curve, and dissipated strain energy. These were used as the failure criterion.

Thesis (M.S.)--University of Wisconsin--Madison, 1991.
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碩士
國立臺灣科技大學
營建工程系
100
In this study, the slag and metakaolin which contain rich elements of silica and aluminium were used to manufacture three types of composite geopolymer: Type A (70% metakaolin and 30% slag), Type B (30% metakaolin and 70% slag) and Type C (100% slag). Both the sodium hydroxide and sodium silicate solution were used as the activators. Type A composite geopolymer uses three water glass moduli of 0.6, 0.8 and 1.0, three concentrations of alkali activator (11, 13 and 15%) and three water-to-solid ratios (0.55, 0.60 and 0.65), while Types B and C use the water glass moduli of 0.6 and 0.7, the e amount of alkali activator of 9% and 7%, and the water-to-solid ratios of 0.45 and 0.33, respectively. The engineering properties of flowability, initial and final setting times and polymerization temperature at the fresh state and the compressive strength, dynamic elastic and shear moduli, ultrasonic pulse speed, dry shrinkage and thermal properties at hardened for Type A composited geopolymer were studied. But only the engineering properties at hardened state for Types B and C were investigated. The results of study show that: 1. The flowablity of Type A composite geopolymer increases with the increase of the concentration of activator and water-to-solid ratio to reach a best flowability ratio of 125%. The increase of water glass modulus and activator concentration and decrease of water-to-solid ratio tend to reduce the setting times and increase the polymerization temperature with a shortest final setting time of 1.8 hours and a highest temperature of 81oC. 2. The dynamic elastic and shear moduli, ultrasonic pulse speed and thermal conductivity of Types A, B and C geopolymer increase with the increase of sand content with 15%, 96%, 74%, and 11%, 110%, 73%, and 21%, 16%, 9%, and 100%, 48%, 65%, respectively. But both the compressive strength and dry shrinkage decrease with the increase of sand content with 23%, 10%, 22%, and 74%, 35%, 62%, respective. 3. Type A composite geopolymer exhibits a state of uniform shrinkage, but Types B and C show a state of uneven shrinkage.

碩士
國立交通大學
土木工程系所
103
The purpose of curing is to prevent excessive evaporation of water from the concrete to achieve full hydration to improve quality of the concrete. With today’s environmental consciousness of human being, the progress of material technology and economic needs, the use of mineral admixtures (slag, fly ash) often replace part of cement, but pozzolanic reaction of mineral admixture is in the later age than the hydration reaction of cement. This makes curing more important to guarantee the effectiveness of pozzolans. This study use different water cementitious ratio with the addition of SCA to test the fresh and hardened concrete’s properties, including mechanical properties, volume stability and durability. Several curing regimes were employed for comparison. And multi-variable regression analysis was executed. It is found that different w/cm ratios exhibit different performince in terms of strength, shrinkage, water loss, RCPT, and surface electrical resistance. In addition, it is also found that steel rebar can effectively restrain the shrinkage, and better for higher steel ratio.

碩士
國立成功大學
土木工程學系碩博士班
98
Porous asphalt concrete is an alternative to traditional hot mix asphalt and is produced by eliminating the fine aggregate from the asphaltmix. Rain that falls on the friction course drains through the porous layer to the original impervious road surface at which point the water drains along the boundary between the pavement types until the runoff emerges at the edge of the pavement. Porous asphalt concrete overlays are used to improve drivability in wet weather conditions and to reduce noise from highway traffic. The void space in porous asphalt concrete overlay layer generally is 15-25%. Taiwan special climatic environment, enables porous asphalt concrete to have the opportunity to be at the moist condition for a long time. This research uses the same porous asphalt concrete mix design result, coordinates three kind of different asphalt to make the mixture: AR-8000 asphalt, high viscosity asphalt and modified III asphalt. And soaks mixtures in water on 60℃ several days: 0, 1, 3 and 7 days. Mixtures after the immersion condition function carries on the project experiment: The indirect tensile test, the static creep test, the dynamic creep test, the track test, and the resilient modulus test, to appraise the different immersion condition function to influence of the porous asphalt concrete mixture. This ratio of parameters affected by moisture conditioning to the control state is referred to moisture damage ratio. Demonstrated according to the result that without immersion condition, three kind of mixture's indirect tensile are close. After immersing 1 day-long condition function, the indirect tensile of AR-8000 asphalt mixture drop is 0.8 time, the indirect tensile of modified III asphalt mixture drop is 0.86 time, the indirect tensile of high viscosity asphalt mixture drop is 0.89 time. And immerses 3, 7 day-long condition functions to present the same tendency, the high viscosity asphalt mixture has the higher moisture damage ratio, and the AR-8000 asphalt mixture has the lower moisture damage ratio. Other test result all presents the same tendency. Synthesizes each result, the high viscosity asphalt mixture and modified III asphalt mixture are highly resistant to moisture damage, and AR-8000 asphalt is lowly. In addition antistrip additive was effective to decrease the moisture damage in AR-8000 asphalt mixture.

碩士
國立屏東科技大學
土木工程系所
101
Post-installed anchors include chemical adhesive anchors and mechanical anchors. The post-installed anchor is relatively easier than pre-installed anchor due to on-site construction requirement during installation. M12 chemical anchor, one a half inch mechanical expansion anchor bolt (drop-in anchor), and M12 mechanical screw-in Anchor (Concrete screws) were used in the study. ASTM E488-96, ASTM E1512-01, ICC AC58, ICC AC308 are the reference standards. A comparison tensile test was conducted in dry and wet conditions for the chemical anchor. Tensile test using expired chemical grout was also performed to evaluate the aging behavior of the chemical bonding agent. The tensile strength for the chemical anchor in wet condition was about 15.4% lower than the dry condition. The tensile strength for those anchors installed using expired bonding agent showed no influence. Sliding failure occurred at the interface between anchor and concrete at near 63% of its ultimate tensile strength for the test expansion anchors. The diameter of the concrete failure cones for the screw-in anchor were extended around 4 times of its installation depth which is wider than the data showed in ASTM standard. The shear strength for chemical anchor, expansion anchor bolt, and screw-in anchor was controlled by the shear strength of steel bars. Minor concrete compression failure was also observed near the edge of steel bar during the shear test of screw-in anchor. No torsion failure was observed at 200 N-m torque force for the chemical anchor and screw-in anchor. However, the average torque strength was 78 N-m for the expansion anchor. According to the ICC AC308 standard, 55% UTS tensile force was used for the creep test for the chemical anchor. No creep failure and linear creep strain curve in semi-log scale were observed for the creep tests.

The aim of the Project is to find out the geo-engineering properties of fly ash, which can act as a stabilizer to many soils in geo-engineering field. The project describes the use of local fly ash in construction industry in a way to minimize the industrial waste. Their been serious shortage of natural material, which are used in Highway or Earth dam construction. Due to soil excavation, deforestation occurs which affects the bio-diversity. Industrial waste such as fly-ash, slag etc can be effectively used in soil stabilization. Several geo engineering Labrotory experiments were performed on fly ash to determine its properties, which may be used in road construction, earth dam construction, soil stabilization etc. If these materials can be used in highway or dam construction, it will be a great effort in minimizing the industrial pollution. Fly ash was collected from captive power plant from the dump pad of Rourkela steel plant. These are stored in air tight container after being oven-dried. Experiments such as determination of compaction properties, CBR analysis, Un-confined compressive strength test, permeability etc are done in order to determine the geo-engineering properties of fly ash, which can taken account in the construction field. A brief comparison is made between fly ash and other soil properties which are used as sub-grade, base in Highway construction.

碩士
朝陽科技大學
營建工程系碩士班
92
The main purpose of this study is to study the influence of soil gradation and slag cement content on the engineering properties of soil cement. The soil was taken from Wu-xi river bank, the sample of soil passed the sieve number 200 of 10% and uniformity coefficients of 2, 10, 20 and 30. The soil was mixed with various slag cement contents to make soil cement specimens. To study the durability, strength and permeability properties of soil cement, laboratory tests, including the wetting and drying test, unconfined compression test, Brazilian tensile test, and high pressure permeability test for soil cement, were performed. The results of the study show that the well-graded soil cements have the highest dry densities and the lowest optimum water contents. The higher uniformity coefficient of soil cement is, the less optimum water content is. As the mixed cement content increased, the durability of soil cement increased during the wetting and drying test. The compression or tension strength of soil cement is dependent on curing time and the mixed cement content. The 28-day compression strength of the soil cement is 1.68 times larger then the 7-day compression strength, and 1.3 times for the tension strength. The relation between the strength and time is approximately linear from the results of this study. Modulus of elastic, unifined compression strength, and tension strength of the well-graded soil cement are higher than those for poor-graded soils. Soil cement is a near impermeable material from the results of high pressure permeability tests, and the permeability coefficient decreased as the mixed cement content of soil cement increased.

碩士
國立屏東科技大學
土木工程系碩士班
91
ABSTRARCT The effects of geosynthetic reinforcement on uniform Quartz sand using a polypropylene silt-film geotextile and a rigid biaxial geogrids were studied. The medium particle size (D50) of the Quartz sand is 0.78 mm. The effect of reinforcement on soil-geosynthetic formed composite material was investigated by load plate tests, conventional triaxial tests, and small strain cyclic triaxial tests. The load plate test results indicated that great majority reinforcement effect is contributed from the top layer of geosynthetics. Placing geosynthetics at the location 0.28 load plate diameter below the ground surface showed the best reinforcement effect. The increase of number reinforcing layer within 20-cm diameter triaxial specimen will proportionally increase the shear strength of the reinforced material. Geotextile showed better interlocking and reinforcement effect with the Quartz sand than that due to the test geogrid. The results of small strain cyclic triaxial tests showed that the Young’s modulus decreased as strain increased, however the damping ratio of the test samples increased as strain increased for pure sand and reinforced sand. The placing reinforcing geosynthetic layer will increase the Young’s modulus and decrease the damping ratio of the specimen. Young’s moduli of the reinforced specimen with 100 kPa confining pressure ranged from 130 Mpa to 150 Mpa for strain at 3x10-4% to 8x10-4%. When axial strain greater than 0.01%, Young’s moduli of the reinforced specimen is greater than 100MPa. Young’s moduli of the sand specimen is smaller than 100MPa. The results of small strain cyclic triaxial tests showed that the Young’s modulus increased as lay reinforced materials. Key Words: reinforcing soil, Young’s modulus, damping ratio, loading plate test.

博士
國立成功大學
土木工程學系
104
Gussasphalt (Guss) is mainly used in the steel deck bridge, of which designed goals are the high fluidity and zero porosity to protect steel deck . The strength of Guss is mainly related to asphalt mastic. Therefore, this study firstly focused on Guss paste to investigate its basic properties, and then stimulated the aging effect on its mixing in the lab in order to implement the basic engineering property testing and strain-controlled fatigue testing for Guss. In addition, the results of the high-temperature rutting analysis and the fatigue life definition could be provided as the reference for the pavement material and construction specifications for Guss. The research results of Guss paste indicated that the increase of Trinidad Lake Asphalt (T.L.A.) and aggregate content and the aging effect resulted from the mixing time would increase the stiffness of mastic; however, the aging effect on the phase angle was more significant than T.L.A. and aggregate content to the phase angle. Moreover, different types of asphalt were applied to be the binding materials to mix with T.L.A., and there’re several differences existed in the paste properties. The study results of Gussasphalt showed that differences in temperature and asphalt content had high sensibility to Guss fluidity, and the asphalt content had a significant effect on the dynamic stability. Furthermore, the results of fatigue test showed that Guss’s fatigue life was longer than traditional asphalt mixtures. In terms of defining fatigue life, it should be based on the definition of traditional fatigue life and stiffness change curve to obtain a consistent fatigue life. The actual engineering case, Guoxing Bridge of National Freeway No. 6, is adopted as the subject for analysis and investigation, in order to propose the explanation and introduction to domestic Guss material property, mix design and engineering technology, as references to the engineering specifications of current Guss construction.

碩士
國立臺灣大學
土木工程學系
86
Waste tire is worth recycling. We can use shredded tire chips as light weight embankment. In order to verify the geotechnical properties of waste tire chips, this study proceeds the constant head permeablity test and triaxial permeability test to measure the permeability of waste tire chips. Besides, this study experiments the direct shear test and triaxial consolidate-drain test to gain the shear strength of waste tire chips. In this study, we also use direct loading consolidation instrument to understand the compression behavior of waste tire chips, and forecast the creep behavior of waste tire chips by analyzing with Gibson and Lo model.

碩士
國立中央大學
土木工程研究所
82
Since the space available for land fill of refuse is limited, incineration treatment to reduce the amount of refuse has become a major method for the future. In Taiwan area, according to the current plan, by 1998, there will be 22 incineration plants constructed and operating.Then, the incinerator residue generated will be around 22000 tonnes per day. Such a huge quantity of residue will alsopose disposal problems. Incinerator residue is composed of fly ash and slag (button ashes). Fly ash, which contributes a smaller portionin the residue, perhaps contains heavy metals and notsuitable for the engineering applications. But for slag,which is the major component in the residue, there is no such apprehension. Base on gradation analysis, fly ash could be categorized assilty sand and slag and may be classified aswell-graded gravel with sand. Both of them have the potential of pozzolanic reaction with cement or lime due to the characteristics of chemical compositions and crystal structure. The test results have indicated slag can be compacted easily and its peameability is similar to fine sand or silt. It also possesses low compressibility and high strength characteristics because of the angularity and surface roughness of particles. However,the shape and sedimental structure of particles may cause large settlement of loose slag landfill in earthquake. If the density is increased adequately, the settlement could be controlled.The investigation of liquefaction potential has indicated that local liquefaction may occur if the drainage path of slag landfill is limited and the grain size is smaller than No.4 sieve. Generally, the phenomenon of liquefaction may not occur in its original grain size distribution of unsieved slag. The test results previously described show that slag can be a promising source of fill material, if compaction is adequately performmed. The utilization of slag would help alleviate the incinerator residue disposal problems and produce usable lands.

碩士
正修科技大學
營建工程研究所
102
In this paper, oyster shell powder, mudstone powder, waste liquid crystal display powder, swell, flux material allocation, after drying and made into globular tile aggregate of different diameters through the processes of water spray , rolling and granulating, then this ratio were used in eight kinds of sintering, and select the best ratio of firing into a lightweight aggregate, Hwang’s densified mixture design as a concrete mix design, made of poured concrete. Then concrete is made to discuss the relations among curing time, compression strength, elasticity modulus, and thermal conductivity ratio. A series of tests are made to obtain the regression curves as references for engineering and construction. The research results show that, in the granulation sintering mix ratio, cylinder compressive strength limits between 25.09kgf/cm2 and 127.42 kgf/cm2, water absorption falls between 1.57% and 12.84%, loose unit weight limits between 1.19g/m3 and 1.48g/m3, Among them, for M10-TFT64-S20-Na3-NaH3-950 mixture ratio has lowest cost, high cylinder compressive strength , low water absorption ratio, In all concrete mixture ratio, its elasticity modulus, dynamic elasticity modulus, dynamic shear stress modulus, compression stress velocity and shear stress velocity all increase with the growth of the square root of compression strength, Thermal conductivity falls between 0.205 and 0.258, Its thermal conductivity is only half the normal weight concrete, indicating that this kind of green building material is good material.

Hydrogels are of interest to the biomedical field because the hydrated networks can provide a physiological environment where biological species can survive or grow. Genetic engineering of protein polymers—a synthetic technique which provides a superior level of synthetic control without compromising natural composition—was used to prepare materials of the general architecture, rod-coil-rod. A naturally occurring motif, the leucine zipper, describes the rod domain. The leucine zipper can self-assemble when two amphipathic helices come together and are stabilized by contact along their hydrophobic face. The acidic leucine zipper domain, denoted ‘A,’ contains mostly glutamic acid in residues which flank the hydrophobic interface. A polyelectrolyte protein, of the repetitive sequence [(AG)3PEG], defines the coil domain, denoted ‘C.’ AC10Acys displayed reversible gelation as a function of pH and temperature, thus three aspects of the viscoelastic behavior were investigated. The gelation properties were studied by single particle tracking, which monitors the Brownian motion of fluorescent particles imbedded in a protein hydrogel or suspended in a protein solution. First, the physical crosslinks in an AC10Acys hydrogel network were diplaced by the addition of a leucine zipper domain, Atrp. A 2.23 mM AC10Acys hydrogel behaved as an elastic gel at pH 8.5, but upon addition of 1.13 mM Atrp, a viscous solution was obtained. Second, the effect of charge of the leucine zipper domains were examined using, AC10Acys, and BC10Bcys, where ‘B’ denotes a basic leucine zipper domain. Both protiens form viscous solutions at 1.78 mM, pH 8.5 or pH 7.4, however, upon combination of AC10Acys and BC10Bcys, a stiff elastic gel is formed. Finally, a series of triblock proteins with increasing midblock length were genetically engineered to study the influence of midblock length on the gelation behavior of triblock proteins. The pH and concentration dependences of gelation of ACxAcys, where x = (20, 30, 40, 50), were examined by single particle tracking. Whereas AC10Acys was found to gel around 2.23 MM, pH 8.0, the concentration required for gelation decreases to 1.27 mM for the protein with the longest midblock length, AC50Acys.

碩士
國立屏東科技大學
土木工程系所
103
The objective of this study is to investigate the engineering properties of concrete use post installed mechanical anchors. M8 and M10 screw anchors and M8 undercut expanded anchor were used in the studied. Tensile and shear strength, and seismic tensile and shear test of single anchor, and edge effect and spacing effect of multiple anchors under tension and shearing loading conditions were investigated. Un-cracked concrete with nominal compression strength of 20.6 MPa and 51.5 MPa were used. ASTM E488 standard test methods, ACI 355.2 standard, and ETAG 001 guideline were followed in the test program and analyses. Concrete strength of each test was normalized according to ACI code in the analyses. Nominal installation depths of 70 mm, 80 mm, and 50 mm were used for M8 and M10 screw anchors, and M8 undercut expanded anchor. Installation depth of 50 mm for M8 screw anchor was also used for comparison studied. Preliminary brittleness of concrete screw anchor was also investigated. Because the test screw anchors are made from harden steel, the average tensile strengths for the M8 screw anchor were 35.46 kN and 20.86 kN for 70 mm and 50 mm embedment with concrete cone breakout failure mode, respectively. 70 mm embedment was found to be appropriate for the test M8 screw anchor. The average tensile strength was 22.32 kN with 50 mm embedment for the expansion anchor. 50 mm embedment seems to be sufficient for the test M8 sleeve expansion screw. Similarly, due to the M8 screw anchors is made from harden steel, the average shear strength of the screw anchor was 25.90 kN and is much higher than that, 14.87 kN, for the M8 sleeve expansion anchor. No reduction on the residual tensile strength and shear strength were observed for both M8 screw and expansion anchors after subjected to ACI specified seismic loadings. Both anchors can be classified as Type 1 anchors under tension and shear seismic loading conditions. The results of the edge effect test showed that condition with edge distance of 160 mm with C/hnom ratio of 2.0, the strengths for tension test and shear test are all similar to those for the reference conditions. The spacing effect test anchors were installed with edge distance of 80 mm. The tensile strength for the spacing of 240 mm was almost double to that of reference condition. In addition, the shear strength with the spacing distance of 320 mm was about twice of that for single anchor condition. The suggested installation spacing ratios s/hnom with edge distance of 80 mm condition subjected to tension load and shear load are 3.0 and 4.0, respectively. Preliminary brittleness study was conducted for the M10 screw anchor with the nominal compression strength 51.5 MPa concrete. Further study is continued.

博士
國立成功大學
土木工程學系碩博士班
93
Development of novel concrete materials using soil is an emerging discipline of research both domestically and internationally. The prospect of this new discipline is the creation of a wide range of engineering materials for the use in ecological construction methods and materials that can be used perpetually. Three soil materials are being developed under this research. The first material named ready-mixed soil material can be used for backfilling to underground structures. The second material named modified ready-mixed soil material, is resistant to shrinkage cracks and can be used above ground for non-structural purposes. The third material named environmental soil material has strengths up to 20 MPa, and can be used in main structures. The results of the study indicate: (a) Ready-mixed soil material has a number of advantages such as safe to use, friendly to the environment, low cost, rapid speed of construction and the ability to re-excavate at a later date. (b) The modeling of cementation between mudstone and gypsum in a natural Yadan topology has lead to the development of a modified soil material. Such material calls for the addition of gypsum to clayey soils as modifying agent. By further mixing cement to this modified soil, the modified ready-mix soil material is resistant to the development of dry shrinkage cracks. (c) By calcinating soil minerals to high temperatures and adding active minerals, silicate and aluminate monomers in soil are disintegrated by use of strong alkalis. Na2SiO4 is used to synthesize a soil polymer that resembles the structure of zeolite. Such material can be fully recycled as an environment friendly soil material that can be further developed for use in main structural members.

博士
國立臺灣海洋大學
材料工程研究所
104
This study is focus on the utilization of by-product materials included the combination of CFBC ash, WIBA, AIBA, PIBA, IBA, GGBS and silica fume mixed following the designed proportions as green cement-based materials, and the engineered properties included mechanical properties, permeability, corrosion behaviors, pore distribution as well as SEM observation were conducted in order to verify the feasibility of those by-product materials mixtures used as the application of green cement-based materials such as controlled low strength materials. Test results indicate that those by-product materials can be processed by melting to regain reactive pozzolanic activity, which may be used to partially replace cement. And CFBC also can be used to partially replace fine aggregates as controlled low strength materials. In addition, inclusion of silica fume into steel fibers concrete results in a significant increase in compressive strength and abrasion resistance. Cement-based materials containing above-mentioned by-product materials as green cement-based materials display better perfoemance on mechanical properties, permeability, corrosion resistance and denser micro-structure. In conclusion, the utilization of above-mentioned by-product materials is important to sustainable development in concrete industry and is suitable for a composition of green cement-based materials.

Thesis (M.S.)--University of Wisconsin--Madison, 1999.
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Age and disease can cause changes in the mechanical properties of ocular tissues, which compromise visual acuity and can lead to blindness. Thus, there is great interest in understanding the mechanical properties of ocular tissues and in developing appropriate therapeutic strategies. The goal of this thesis is to discover and manipulate the molecular mechanisms that determine the bulk physical properties of the vitreous and the cornea. Both tissues are ordered biocomposites of fibrous collagen embedded in soft matrices of proteoglycans (PGs) and glycosaminoglycans (GAGs). The hydration state, mole fraction, and organization of these components determine the mechanical properties of their respective tissues. We describe the use of a novel "cleat geometry" for rheometry in shear to quantitatively measure the rheological properties of vitreous and other soft biomaterials. Where as the mechanical strength of these tissues has traditionally been attributed to their collagenous components, results from coordinated mechanical and biochemical analyses suggest that PGs and GAGs also make significant contributions. We hypothesize that hyaluronan contributes to the mechanical properties of the vitreous through a Donnan swelling mechanism that induces a state of tension in the collagen network. We hypothesize that the PG/GAG matrix plays a significant role in the mechanics of the cornea by restricting the translation and deformation of the collagen fibrils.

Our therapeutic goal in the vitreous is liquefaction: we seek pharmacological agents capable of separating the vitreous from the retina and destabilizing the network without damaging the adjacent tissues (retina and lens). We present evidence that using urea to disrupt hydrogen bonds may provide clinical benefits by inducing posterior vitreous detachment and reducing the shear modulus of the vitreous.

Our therapeutic goal in the cornea is to stabilize its mechanical properties against the softening associated with keratoconus. We report a clinically-relevant rise in the modulus of corneas treated with glyceraldehyde to induce crosslinking through glycation. We hypothesize that the mechanically-relevant crosslinks are those that change the properties of the soft PG/GAG matrix and its coupling to the collagen fibrils, rather than the much more numerous crosslinks that form within fibrils.

碩士
淡江大學
土木工程學系
84
The slurry consolidation is a way to prepare high-quality specimens in the soil mechanics laboratory. The specimens produced by the slurry consoolidation have the characteristics of being homogeneous in engineering properties and the known stress history. This project mixes the kaolinite with the water to make the slurry for consolidation, the factor of de-air and consolidation time are considered. The cakes, after slurry consolidation, was then divided into three layers. Three specimens can be trimmed from each layer for conventional and constant rate of strain consolidation tests. Rests show that (1) Consolidated cakes are very homogeneous, (2) The primary consolidation time for slurry can be completed within one day, (3) At the void between 1.9 and 2.1, the excess pore water pressure of the slurry begin to dissipate quickly, (4) The coefficient of consolidation decreases initially with the degree of consolidation, then reaches a constant value, (5) For preconsolidation pressure determination, the Casagrande's method is superior than the log-log meyhod, (6) The primary consolidation time, the settlement, and the preconsolidation pressure are prolonged, reduced, and decreased, respectively, for the de-aired specimens, and (7) The preconsolidation pressure, compression index, and the swelling index are different for constant rate of strain and conventional consolidation test specimens.

碩士
國立高雄科技大學
土木工程系
107
The diatomite is a cerium oxide particle containing fine and amorphous. The diatomite skeleton is highly porous, light in weight, chemically stable and inert. This study investigated the engineering properties of diatomite replaced cement to make cement mortar. The test variables include water/cement ratio (W/C) of 0.4, 0.5 and 0.6, and the substitution amount of diatomite is 0%, 5%, 10% and 20%. The curing age is 3, 7,28,and 56 days,and the high temperatures are 300°C, 500°C, and 700°C, respectively.The test results show that the freshening time, fluidity and twist of the fresh-mixed nature are both reduced in workability and shorter setting time as the amount of substitution of the diatomite increases. Compressive strength, flexural strength and ultrasonic pulse velocity of hard and solid properties. Under different water-cement ratios, the compressive strength and flexural strength decrease with the increase of the substitution amount, and the pulse velocity of the ultrasonic pulse velocity decreases. When the substitution amount is 5%, the intensity approaches the 0% control group, and the ultrasonic pulse velocity has a ultrasonic pulse velocity when the 5% substitution amount is used. The durability water absorption rate increases as the substitution amount increases, and the sulfuric acid resistance decreases as the substitution amount increases, and the heat transfer coefficient substitution amount decreases. The high temperature properties show that the residual strength after high temperature at 300°C and 500°C is higher than the original strength of the control group, and the strength is greatly reduced after high temperature at 700°C. After the high temperature, the ultrasonic pulse velocity is lower than that of the control group, and the pulse velocity is attenuated more significantly with the temperature increase. The microscopic OM analysis showed that the substitution amount of diatomite increased and the surface porosity increased. SEM analysis showed that the substitution of diatomite increased the C-S-H colloid in the test sample.

The development of any country depends on increasing the industries and agriculture, which is governed by adequate power supply. In India major source of power generation is by coal based thermal power plants. Present day’s coal based thermal power industries are increasing day by day. Coal available in India is low grade coal with ash content of 30-45% in comparison to imported coal which has low ash content of 10-15%. In India, total 145 coal based thermal power plants are existed by the year of 2014-2015. Thermal power plants are major sources of ash generation. Typically these plants are produces two types of ash materials: Fly ash and Bottom ash. These two types of ash are mixed thoroughly with large quantities of water and sluiced to onsite storage ponds called ash ponds. Massive utilization of pond ash in engineering field requires thorough understanding of its geotechnical properties, especially strength characteristics. In the present study, a detailed experimental investigation was carried out on the strength and other geotechnical properties of pond ash samples mixed with different bentonite content. The main focus of the study was to evaluate the engineering properties of pond ash-bentonite mixes and assessing its suitability in various geotechnical constructions mainly the land fill liner. The Pond ash and bentonite samples are characterized and analyzed for the various geotechnical properties. The various experimental works were carried out to determine the index and engineering properties of pond ash with and without bentonite content. Index properties such as density index, plastic limit, liquid limit and engineering properties such as compaction and consolidation characteristics, shear strength were found by conducting various experiments accordingly. All the experiments were conducted by adding bentonite ranging from 5 to 30% at 5% interval to the pond ash and results were compiled in the graphical form to observe the trends in various parameters.