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The work in this thesis concerns the behaviour of cutting fluids used for drilling aluminium. A cutting fluid which is useful must neither corrode nor stain aluminum unduly. The compositional factors which lead to a successful cutting fluid have been investigated using electrochenucal techniques. Linear sweep and impedance measurements were used to assess the corrosion of pure alummium and aluminium alloys in contact with aqueous solutions in the pH range 8-11 , in the presence and absence of oxygen. It was found that a low corrosion rate required that the solution pH was kept lower than 9.5. Clear and stable cutting fluids were formulated with and without the use of amines and the corrosion of aluminium in contact with these cutting fluid emulsions was studied. The corrosion rate of aluminium was found to be a factor of ten times lower when in contact with a typical emulsion compared to contact with an aqueous borax solution of the same pH. The most important factor in respect of corrosion control was the pH. The presence/absence of amines did not significantly affect the corrosion rates. In order to simulate the drilling process,a glass cell was designed with a glass frit situated at the base onto which an aluminium rotating disc electrode was lowered, and electrochemical measurements were made, in situ in this way. Abrasion of the electrode caused the anodic process on the metal to be affected to a greater extent than the cathodic process. The electrochemical techniques used in this work have readily allowed us to assess the suitability of different cutting fluid formulations.

This research project represents a continuation of the research programme into Precast Concrete Pavement Units, "P. C. P. U. ", which is based in the Department of Civil Engineering at the University of Newcastle upon Tyne. The units were referred to as raft units throughout the thesis which focused on the use of raft units as a full concrete paving system for aircraft parking, taxiway, and other low speed areas, at airports. The physical full scale test model was designed and constructed to represent the applied loading from one of the dual wheel legs of the design aircraft, a Boeing 727-200, when it is taxiing over a raft unit paving system. It was only possible for the test model to be provided with a contact area of 200 mm square compared to the real life of 400 mm square. A theoretical correction was applied to allow for this difference. Sixteen raft units were tested in pairs using the test model. The tests were divided into three modules to investigate the effect of the raft unit dimensions, Module(M1); the reinforcement design, Module(M2); and the raft thickness, Module(M3). The twin loading assembly applied a repetitive dynamic load which was moved manually between four different loading positions to represent the aircraft moving across the raft units. The primary aim of the experimental programme was to identify for the first time the fatigue life and failure mechanisms of the raft units under the influence of twin dynamic moving loads, and provide experimental results to enable a more refined numerical design method to emerge for raft units, as well as to determine the causes of failures and to recommend remedial measures. Observations were made of vertical deflection, concrete strains, crack widths and crack patterns, failure load, and failure modes, each of which were described in detail. The test observations showed that by increasing each of the following variables, namely, the aspect ratio, the amount of steel bar reinforcement and the thickness of the raft units, resulted in each case in an extension of raft unit life. It was found that some form of uplift restraint on the raft unit should be added to improve the fatigue life for one of the loading positions and that fibre reinforcement should not be used. The ultimate load capacity of the raft units was influenced by the loading position, the applied load level and the number of load repetitions, together with the crack patterns. Using the results from the raft units that had failed within a specific module, it was possible to predict the ultimate and reserve load capacity of raft units within the modules that were only partially fatigued. Four important conclusions have been established during the research project. Firstly, based on the test results, an empirical relationship was derived using regression analysis, relating the number of load repetitions to the aspect ratio, the amount of reinforcement, the raft thickness, and the applied loading. This will need further verification, but it should eventually be very useful when estimating the fatigue life of these specific raft unit models. Secondly, a new design method has been proposed. The design methods for raft units proposed previously by Bull, Ismail, Annang, Ackroyd, and the British Port Association were reviewed. The test results enabled a new design method to be developed which was based on Bull's method but proposed new design charts and tables for each of the raft units considered in the research project which introduced the additional variables of contact pressure and the exact loading position. Thirdly, the measured strains were used to develop strain fatigue relationships for designing raft units and estimating the reserve design life in a raft unit paving system for the purpose of maintenance management by relating the accumulated number of load repetitions of a design load to the permissible concrete strain. The strain fatigue equations were generated for each of the raft units considered in this research project. Thus, the most realistic way to control raft unit distress is through the use of a predictive fatigue model. This should prove invaluable to those involved in the maintenance of raft unit paving systems. Finally, life cycle cost analysis was conducted for three types of construction pavement (paving blocks, PQC, and raft units). The analysis demonstrated that the precast concrete raft units will become a viable alternative to conventional pavement construction and a real competitive to the concrete paving blocks.

A new biaxial test procedure, known as the 'plate bending method' is investigated for thin multilayered generally orthotropic laminated plate structures. The method is evaluated with reference to the four criteria for a satisfactory biaxial test. A number of experiments have been performed to determine the applicability of the criteria to the new method. Surface strains, transverse displacements and visual observations have been recorded, from which the bending behaviour and failure mechanisms in the experiments are examined. A classical 2-dimensional thin plate finite element analysis has been developed to predict the stresses generated in the small (linear) and large (non-linear) deformation domains. To minimise computing effort in the analyse of non-linear bending, the formulation omitted the effects of shear deformation, shear stresses, material non-linearities and the exact position of the neutral axis. The omission of these factors has been examined and it is shown that the individual errors are small. Analytical solutions for simple isotropic, and, where available, laminated plate bending examples, have been used to establish the limitations of the finite element analysis. Numerical results have been compared with the measured surface strains and transverse displacements. From the comparison it is shown that the plate bending method can be accurately modelled by the linear analysis. However, the non-linear analysis is shown to be inaccurate when predicting the measured bending for reasons which are discussed.

The study of building stone decay is a field of increasing impOliance. Many previous studies have focused on limestone, and recently on sandstone. These studies can provide information on the spatial and temporal distribution of weathering forms and the degree of impact of polluted urban atmospheres. Several of these schemes rely on subjective visual appraisal by the examiner, which is unreliable and prone to measurement error. To counter these problems, and address the relative paucity of studies on granitic building stone, a novel semi-quantitative measure of rock quality was created. The creation of the Stone Deterioration Index (SDI) allowed the evaluation of longterm granitic building stone decay, while the short-term response of fresh granite to atmospheric exposure was examined through the use of microcatchment units (MCV' s). The measurement of run-off water and the physical response of fresh granite over a 91 week exposure period at three sites of varying pollution concentrations, allowed an assessment of the relative importance of surface roughness, composition and, dry & total deposition on deterioration rates. The exposure programme used MCV's containing granodiorite slabs with different degrees of surface roughness (finish) to collect run-off. This was measured for volume, pH, conductivity, and selected anion and metal concentrations. Run-off concentrations were measured by a Dionex 2000i ion chromatograph and a Perkin-Elmer ICP 40 inductively coupled plasma spectrometer respectively.Site was the most important factor in determining run-off concentrations showing significant variations between the urban and rural sites. Surprisingly, MCl) composition and surface roughness variations had little influence on component concentrations, and there were no systematic significant inter-finish variations. The MCV slabs showed no significant changes in weight, surface roughness or composition as a result of exposure. Granitic carousel tablets of varying composition, designed to assess the relative influence of dry and total deposition on granitic deterioration, also showed no systematic effects from exposure. The lack of significant variation between the pre- and post-exposure characteristics of the MCV slabs and carousel tablets could indicate that exposure length was not sufficient to generate measurable decay features. The assessment of long-term decay rates by the SDI, which was non-destructive and applied in situ, involved the measurement and rating of four parameters (surface strength, surface roughness, surface coatings and discolouration), to form a semi-quantifiable measure of rock quality. Eleven churches in Dartmoor, built between 1430AD-1896AD, were assessed by the SDI to provide a measure of long-term deterioration rates. Cross-church comparisons revealed no consistent effects on deterioration rates with increasing stone height. Aspect, however, did playa major role in influencing deterioration rates. The south facing walls (mean: 60 SDI points) showed the least amount of decay and had the slowest deterioration rate, while west (mean: 56 SDI) and north facing walls (mean: 53 SDI) deteriorated 6% and 14% faster than south facing walls respectively. Results suggest biological weathering was the major process in granite building stone deterioration in the Dartmoor region. These findings correspond to research by Robinson and Williams (1996) on sandstone churches. They ranked aspect by weathering scores derived from visual assessment of individual stone block, and found deterioration features were strongly affected by aspect, in the order; East>North>West>South. Although there is convergence in the decay pattern between aspects for the two stone types, the SDI index was formulated for coarse-grained igneous rocks, where it shows a strong statistical relationship between building age and rock quality (1=0.74). This allowed the formulation of an average linear deterioration rate for granite buildings in a clean, rural environment of 4.59 SDI points per hundred years.

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