For the period of several centuries, the influence of several distinct cultures produced rich and diverse cultural heritage that we see today in East Africa countries. The most tangible remains of these heritages are stone built buildings and structures including, palaces, mosques, residential houses and tombs. At present, these heritages are in different physical state, some are in relatively good condition while many are in an appalling condition. The presence of these historical monuments has benefited these countries economically and culturally therefore, it is essential to ensure that these monuments continue to exist. Material characterisation of the historical buildings and associated structures was used to develop a suitable method of intervention that is sympathetic to the original materials. Mortar is the most damaged material therefore, historical mortar from Stone Town historical buildings and associated structures has been characterised by visual examination, optical microscopy, x-ray diffraction and hydrostatic weighing and the results have been compared. The historical mortar is mainly comprised of calcite, quartz and feldspar. The mortar condition has been divided into hard mortar, soft mortar and, soft and friable mortar. The deteriorated mortar that required consolidation is soft mortar and, soft and friable mortar with a porosity of approximately 27%. Calcium hydroxide solution (limewater) has been selected as consolidant and the consolidation procedure involves two steps. Firstly a limewater impregnation procedure has been developed and secondly, the effect of limewater treatment has been determined. For the application procedure it has been observed that, when limewater comes into contact with calcium carbonate a precipitation reaction occurs and that is the cause of poor penetration ability of calcium hydroxide solution. Major influencing factors on the penetration ability of calcium hydroxide solution have been established as, application method and absorption capacity of the treated material during the impregnation process. Optimization of the penetration ability of calcium hydroxide solution has been achieved by impregnating from the middle of the impregnated specimen. Sugar has been used to study the influence of additive on enhancing calcium hydroxide solubility. It has been verified that solubility of calcium hydroxide in a solution of sugar is proportional to the amount of sugar in the solution. Porosity and strength tests have been used to study the effectiveness of calcium hydroxide treatment. Under the conditions studied no appreciable change of porosity has been detected. It is postulated that the calcium hydroxide was deposited at the binder/aggregate interface and at the secondary pores. In terms of strength, evidence has been found to suggest the strength increment varies quantitively with the amount of calcite crystals deposited. / QC 20100803

Corrosion of reinforcing bars is the major cause of deterioration of reinforced concrete (RC) structures in North America, Europe, the Middle East, and many coastal regions around the world. This deterioration leads to a loss of serviceability and functionality and ultimately affects the structural safety. The objective of this research is to formulate and implement a general stochastic finite element analysis (SFEA) framework for the time-dependent reliability analysis of RC beams with corroding flexural reinforcement. The framework is based on the integration of nonlinear finite element and reliability analyses through an iterative response surface methodology (RSM). Corrosion-induced damage is modelled through the combined effects of gradual loss of the cross-sectional area of the steel reinforcement and the reduction bond between steel and concrete for increasing levels of corrosion. Uncertainties in corrosion rate, material properties, and imposed actions are modelled as random variables. Effective implementation of the framework is achieved by the coupling of commercial finite element and reliability software. Application of the software is demonstrated through a case study of a simply-supported RC girder with tension reinforcement subjected to the effects of uniform (general) corrosion, in which two limit states are considered: (i) a deflection serviceability limit state and (ii) flexural strength ultimate limit state. The results of the case study show that general corrosion leads to a very significant decrease in the reliability of the RC beam both in terms of flexural strength and maximum deflections. The loss of strength and serviceability was shown to be predominantly caused by the loss of bond strength, whereas the gradual reduction of the cross-sectional area of tension reinforcement was found to be insignificant. The load-deflection response is also significantly affected by the deterioration of bond strength (flexural strength and stiffness). The probability of failure at the end of service life, due to the effects of uniform corrosion-induced degradation, is observed to be approximately an order of magnitude higher than in the absence of corrosion. Furthermore, the results suggest that flexural resistance of corroded RC beams is controlled by the anchorage (bond) of the bars and not by the yielding of fully bonded tensile reinforcement at failure. This is significant since the end regions can be severely corroded due to chloride, moisture, and oxygen access at connections and expansion joints. The research strongly suggests that bond damage must be considered in the assessment of the time-dependent reliability of RC beams subjected to general corrosion.

This research assessed the influence of hydrologic gradients on woody debris dynamics in a Cumberland Plateau watershed, eastern Kentucky, U.S.A. Although the breakdown of wood can be attributed to several different processes, including leaching, biological decay, fragmentation, and transport, the influence of differing flow regimes has been unstudied. The objectives of this study were to examine how stream channel type (temporary vs. perennial) affected wood processing dynamics (i.e., mass loss and macroinvertebrate colonization and standing stock patterns). Two questions were addressed: (1) do mass loss rates of wood differ across hydrological gradients in stream channels?, and (2) do macroinvertebrate colonization and standing stock patterns vary in relation to hydrologic gradients? Although within each channel type both dry mass and ash free dry mass loss followed a negative exponential model (p < 0.05), there wasn’t a significant between-channel difference in mass loss rates (p > 0.05). Breakdown rates (-k) ranged from 0.133 – 0.194year-1 for perennial streams compared to 0.103 – 0.170year-1 in the temporary streams. Collector-gathers comprised the greatest proportion of macroinvertebrates, accounting for 65.5% (temporary) and 59.3% (perennial) of all taxa colonizing wood bundles, followed by shredders (16.1%, 16.8%), predators (16.8%, 20.1%), (scrapers < 0.1% in both reaches) and filtering collectors (1.2%, 3.7%). Overall, there were no significant between-channel differences for total macroinvertebrate abundance, total macroinvertebrate biomass, and similarly for abundance and biomass of all functional groups. There was a trend, however, of decreasing density and biomass over time of collector-gathers and shredders on wood. Overall, hydrological gradients had no effects on short-term breakdown rates of woody debris or macroinvertebrate colonization patterns. Studies of wood breakdown have been shown to require long study periods (≥ 5 years), therefore, future studies of hydrological gradient may show differing results for woody debris breakdown.

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The risk-based life-cycle management of engineering systems in a nuclear power plant is intended to ensure safe and economically efficient operation of energy generation infrastructure over its entire service life. An important element of life-cycle management is to understand, model and forecast the effect of various degradation mechanisms affecting the performance of engineering systems, structures and components. The modeling of degradation in nuclear plant components is confounded by large sampling and temporal uncertainties. The reason is that nuclear systems are not readily accessible for inspections due to high level of radiation and large costs associated with remote data collection methods. The models of degradation used by industry are largely derived from ordinary linear regression methods. The main objective of this thesis is to develop more advanced techniques based on stochastic process theory to model deterioration in engineering components with the purpose of providing more scientific basis to life-cycle management of aging nuclear power plants. This thesis proposes a stochastic gamma process (GP) model for deterioration and develops a suite of statistical techniques for calibrating the model parameters. The gamma process is a versatile and mathematically tractable stochastic model for a wide variety of degradation phenomena, and another desirable property is its nonnegative, monotonically increasing sample paths. In the thesis, the GP model is extended by including additional covariates and also modeling for random effects. The optimization of age-based replacement and condition-based maintenance strategies is also presented. The thesis also investigates improved regression techniques for modeling deterioration. A linear mixed-effects (LME) regression model is presented to resolve an inconsistency of the traditional regression models. The proposed LME model assumes that the randomness in deterioration is decomposed into two parts: the unobserved heterogeneity of individual units and additive measurement errors. Another common way to model deterioration in civil engineering is to treat the rate of deterioration as a random variable. In the context of condition-based maintenance, the thesis shows that the random variable rate (RV) model is inadequate to incorporate temporal variability, because the deterioration along a specific sample path becomes deterministic. This distinction between the RV and GP models has profound implications to the optimization of maintenance strategies. The thesis presents detailed practical applications of the proposed models to feeder pipe systems and fuel channels in CANDU nuclear reactors. In summary, a careful consideration of the nature of uncertainties associated with deterioration is important for credible life-cycle management of engineering systems. If the deterioration process is affected by temporal uncertainty, it is important to model it as a stochastic process.

The risk-based life-cycle management of engineering systems in a nuclear power plant is intended to ensure safe and economically efficient operation of energy generation infrastructure over its entire service life. An important element of life-cycle management is to understand, model and forecast the effect of various degradation mechanisms affecting the performance of engineering systems, structures and components. The modeling of degradation in nuclear plant components is confounded by large sampling and temporal uncertainties. The reason is that nuclear systems are not readily accessible for inspections due to high level of radiation and large costs associated with remote data collection methods. The models of degradation used by industry are largely derived from ordinary linear regression methods. The main objective of this thesis is to develop more advanced techniques based on stochastic process theory to model deterioration in engineering components with the purpose of providing more scientific basis to life-cycle management of aging nuclear power plants. This thesis proposes a stochastic gamma process (GP) model for deterioration and develops a suite of statistical techniques for calibrating the model parameters. The gamma process is a versatile and mathematically tractable stochastic model for a wide variety of degradation phenomena, and another desirable property is its nonnegative, monotonically increasing sample paths. In the thesis, the GP model is extended by including additional covariates and also modeling for random effects. The optimization of age-based replacement and condition-based maintenance strategies is also presented. The thesis also investigates improved regression techniques for modeling deterioration. A linear mixed-effects (LME) regression model is presented to resolve an inconsistency of the traditional regression models. The proposed LME model assumes that the randomness in deterioration is decomposed into two parts: the unobserved heterogeneity of individual units and additive measurement errors. Another common way to model deterioration in civil engineering is to treat the rate of deterioration as a random variable. In the context of condition-based maintenance, the thesis shows that the random variable rate (RV) model is inadequate to incorporate temporal variability, because the deterioration along a specific sample path becomes deterministic. This distinction between the RV and GP models has profound implications to the optimization of maintenance strategies. The thesis presents detailed practical applications of the proposed models to feeder pipe systems and fuel channels in CANDU nuclear reactors. In summary, a careful consideration of the nature of uncertainties associated with deterioration is important for credible life-cycle management of engineering systems. If the deterioration process is affected by temporal uncertainty, it is important to model it as a stochastic process.

Pavement Management Systems (PMS) are widely used by transportation agencies to maintain safe, durable and economic road networks. PMS prioritize the maintenance and rehabilitation of pavement sections by evaluating pavement performance at the network level. There are many PMS software packages that have been developed over the past decades for provincial/state road agencies. However, sometimes due to lack of budget and experience, adopting the existing PMS for a road agency is not cost effective. Thus, it is important to introduce a simple, effective, and affordable PMS for a local agency and municipality. This research is carried out in partnership between the City of Markham and the Centre for Pavement and Transportation Technology (CPATT) located at the University of Waterloo. For the purpose of developing a PMS for local agencies, an extensive literature review on PMS components was carried out, with emphasizing data inventory, data collection, and performance evaluation. In addition, the literature review also concentrated on the overall pavement condition assessment. In July 2011, a study on “Evaluation of Pavement Distress Measurement Survey” was conducted as a part of this research and was distributed to cities and municipalities across Canada. The study focused on the current state-of-the-practice in pavement distress and condition evaluation methods used by local agencies to compare the results from the literature review. The components of the proposed PMS framework are also developed based on the literature review with some modifications and technical requirements. The City of Markham is selected as a case study, since it represents a local agency and provides all the data, to illustrate the validation of the proposed PMS framework.

The development of hemodialysis clinics in Taiwan has been rapid for about 17 years. In early days, many patients with no health insurance had to get hemodialysis at their own expense. Therefore, they often suffered pulmonary edema caused by breathing difficulties, and quickly rushed into medical centers and then stayed almost all night in the emergency of dialysis. Dialysis clinics were not very popular in communities at that time. Dialysis payment firstly was paid by civil servant insurance then Labor Insurance came second; followed by Agricultural Insurance, and eventually developed into the National Health Insurance. Among them, those dialysis patients are actually the primary beneficiaries. The National Health Insurance gives rise to a large number of community-based dialysis clinics to set up massively. The free competition creates a high-quality dialysis environment. The Japanese people are impressed by both the hardware and software of dialysis clinics. Japan dialysis payment is about 3.75 times of Taiwan. In recent years, the financial deterioration of health care benefits caused a decline in the value of pay- points! And the discussion about health insurance rates is not rationally debated by our society .As a result, the survival of dialysis clinics is really becoming a serious issue. The Taiwanese hemodialysis clinics are still able to provide high-quality dialysis services to the community. Such a successful experience in the Chinese region will surely set a practical example for China, which is in its rapid economic development and has a gradual increase in health insurance coverage now. Besides, the difficulty that faces China is the long serious shortage of basic dialysis medical supplies! So we hope to bring our experience in Taiwan to China dialysis clinics for the future planning in primary health care in the operation and management of dialysis. This research has done the literature review, expert interviews, and service pathway system. According to the three key elements, we analyze and find that Taiwan's experience in China is based on the critical success factors from expert opinions and clinics operation core. This study summarizes and organizes in the paper the following points: 1.service pathway system 2. hemodialysis clinics in communities 3. hemodialysis clinics resource management 4. safety planning and implementation in health care 5. education and training for the medical care personnel 6.cooperate communicate and develop with other organizations to improve management pattern continuously 7. The support from China government health organs

Exposure to atmospheric conditions results of deterioration in historic monuments. and their stones. Limestone conservation presents many problems that have to be investigated in detail. In this study, limestone deterioration and development of its conservation treatments were investigated through examination of the statues carved from karstic limestones in Nemrut Dag Monument. The decay mechanisms that had major roles in their deterioration during two thousand years of exposure to atmospheric conditions and the development of their conservation treatments involved several types of analyses that were carried out in the field and in the laboratory. Exposed surfaces of limestones having karstic veins, interior crack surfaces were examined and compared with relatively undeteriorated interior parts. Similar limestones from the geological formations nearby were artificially deteriorated by salt crystallization and were also examined for comparison. Standard physical and physicomechanical tests, petrographical analysis, XRD, SEM-EDX and FTIR were used during those examinations. Swelling nature of clays in limestones and their control were quantified by CEC measurements. The micro structure of limestone was observed to be composed of micritic calcite with karstic veins of sparitic calcite crystals. Some karstic zones were found to be preferred sites of dissolution and precipitation of calcium carbonate where swelling action of clays and widening of cracks occurred. Iron oxides that moved through those zones, as well as biological activity were also found to contribute to those phenomena. Preparation of high concentrations of nanodispersive calcium hydroxide solutions was achieved for the conservation treatments of the deteriorated limestone. Success of treatments with nanodispersive Ca(OH)2 solutions targeted to the decay zones were discussed in terms of their ability to control the swelling action of clays, carbonation of nanodispersive solution, and improvement in the physicomechanical properties of treated limestone.

In this study, it was aimed to develop conservation methodologies for the historic sandstones using the case of Nemrut Mount Monument to help their survival in open air conditions. The main conservation approach of this study was holistic as well as aiming at minimum intervention targeted to the problem areas. The most important weathering forms of Nemrut Sandstones were material loss due to loss of scales and granular disintegration as well as detachments by scales, back weathering due to loss of scales, cracking, granular disintegration, rounding/notching and discoloration/biological deposition. Deterioration mechanisms of sandstones were studied on deteriorated and relatively sound sandstones by nondestructive methods of UPV and QIRT, and by microstructural analyses using thin section, XRD and SEM-EDX analyses. In addition, the changes in physical and physcomechanical properties such as, color, bulk density, effective porosity, hydric, hygric and thermal dilatation and CEC of clays were determined. Sandstone deterioration was caused by swelling of clay minerals distributed in their matrix and clay accumulations between the detaching scales. Considerable thermal dilatation characteristics was also an important decay factor. Iron oxides caused discoloration at the surfaces, their phase changes was thought to be important in decay. The use of surfactant DAA, to control clay swelling was found to decrease the hydric dilatation by 40%. The consolidation treatments with nanosilica and silicate dispersions namely Funcosil KSE500STE, SytonX3, KSE300 and KSE100 have improved physicomechanical properties as followed by UPV measurements and decreased hydric dilatation. Their long term behaviour needed to be further investigated.