This thesis contains a review of literature relevant to the use of chalk as common embankment fill, and the results of a considerable amount of testing to find the variability of the density and plasticity of the Chalk, its strength properties and compressibility. Various available empirical suitability tests are reviewed, and the final section concludes with six case records which illustrate practical experience and demonstrate the relevance of the research. In assessing the variability of the Chalk over 600 determinations of intact dry density and 200 plasticity tests have been carried out on samples collected from almost all parts of the outcrop in England. These tests indicate the extreme variability of the material, which during excavation may behave in extremes as a rock or a slurry. Strength tests have been carried out on remoulded Chalk using the triaxial and C. B. R equipment. It is shown that the undrained triaxial shear strength is strongly dependent on the remoulded liquid limit of crushed chalk and that the liquid limit approximately corresponds to the saturation moisture content and to the point at which the triaxial strength becomes negligible. Effective strength tests show that while the effective angle of friction varies only slightly for most remoulded chalks, it may increase with time as a result of recrystallization of aragonite within a fill. Compression tests on blocky chalk and on chalk fines above and below their liquid limit are reported, and indicate that few field problems are likely to arise from this type of compression. The collapse of chalk fill upon wetting has been modelled in the laboratory and is shown to provide a much greater threat to the satisfactory performance of embankments. The investigations into suitability have indicated that no completely satisfactory test exists to predict the performance of chalk in earthworks. The use of a simple hand dynamic penetrometer is proposed, and its results are correlated to those of the vibratory crushing test.

Excessive rutting, one of the major distress modes of bituminous pavements, is mainly caused by the accumulation of load-induced permanent deformation. However, current pavement design approaches against the excessive rutting are mainly developed using the theory of elasticity. Recently, a new pavement design approach based on the shakedown concept has attracted lots of attention because it can consider plastic properties of pavement materials. However, most of the existing shakedown solutions were developed for pavement foundations composed of granular materials and soils. Very limited work has been reported on bituminous pavements. Besides, current studies usually assume homogeneous, isotropic pavement materials obeying an associated plastic flow rule (termed as standard materials in the present study), which may not be realistic for pavement materials. In the present research, a step-by-step numerical approach was used to obtain numerical shakedown limits of pavement structures under repeated moving loads. Both two-dimensional and three-dimensional problems were considered. It was found that, under the assumption of standard materials, the obtained numerical shakedown limits and residual stress fields agreed well with the available theoretical data. A static (i.e. lower bound) shakedown approach for pavements with anisotropic, heterogeneous materials was developed based on Melan’s lower bound theorem and the critical residual stress method of Yu and Wang (2012). The influence of material plastic flow rules on pavement shakedown limits was also evaluated both numerically and theoretically. It was found that neglect of the inherent material properties (i.e. anisotropy, heterogeneity and non-associated plastic flow) could overestimate the real shakedown limits of bituminous pavements. A series of tests were conducted to validate the shakedown concept for the responses of bituminous pavements under traffic loads. Two distinct phenomena corresponding to shakedown and non-shakedown were observed. Triaxial tests and uniaxial compression tests were also undertaken to obtain the stiffness and strength parameters, from which the theoretical shakedown limits can be calculated. Comparison between the experimental results and the theoretical solutions revealed that the current 3D shakedown approach for standard materials may overestimate capacities of bituminous pavements. Finally, the lower bound shakedown approach was employed to design a typical bituminous pavement. A direct comparison was made between the shakedown-based design and the current UK design method. It demonstrated that the shakedown-based design for bituminous pavements can be conducted considering the maximum contact pressure and a relatively high air temperature.

The container transportation problem involves designing routing plans for a fleet of vehicles to accommodate requests from multiple ports. A request is a transshipment activity that involves loading a commodity at the source port and then unloading it at the destination port. This problem is closely related to the classic vehicle routing problem (VRP). This thesis investigates a real-world, multi-shift container transportation problem with a limited fleet size. In this problem, requests are sent from the customs office via declaration forms. Each declaration form contains several container transport tasks that share the same time window, source port and destination port. The time windows for container transportation in this problem can generally span across several shifts, thus container transportations can be arranged at any shift. Delaying some transportations to later shifts may cause the violation of time window constraints. As a result, strategies that prioritise tasks with closer deadline need to be developed to ensure that all tasks can be completed. This thesis presents the following research efforts towards the container transshipment problem. Firstly, two formulations have been proposed to describe the problem, in which the representation of transshipment requests are simplified as nodes. The network of the ports is then discussed and, based on the network, three sets of problem instances are introduced. This thesis then introduces several insertion-based heuristics, which are able to generate solutions that complete all container transshipment tasks. In order to further reduce the travelling distance in the solutions, two multi-neighbourhood algorithms are implemented and experimental results are presented. The characteristics of solutions are discussed to get a deeper understanding of the problem characteristics. The dynamic version of the problem, in which declaration forms arrive over time, is then studied. A discrete event simulation framework is developed to accommodate the experiment of various commodity holding strategies. This research leads to an intelligent container transportation system that automates the task assignment.

Road structures are important to the survival of nations. As the cost for the rehabilitation and maintenance of highways soars, civil engineers and administrators face the ever present difficulty of meeting current resurfacing and rehabilitation needs. The deterioration of road structures under growing traffic weight and volume is occurring faster than agencies envisaged coupled with increasingly scarce and expensive new materials required. It is now apparent that for planning, design and construction for road structures, the most efficient and cost effective processes, materials and practices available must be appropriately considered. The use of recycled materials as a sustainable alternative is gaining significant worldwide attention. The overall purpose of this research was to conduct an in-depth investigation and analysis into the design and optimisation of Cold Asphalt Emulsion Mixtures (CAEMs) incorporating high contents of Reclaimed Asphalt Pavements (RAP). To achieve the objectives of the research, four proportions of RAP aggregate materials in addition to Virgin Aggregates (VA) were used as categorised below: - Category 1: 0% RAP (no RAP, 100% VA) - Category 2: 50% RAP (50% RAP, 50% VA) - Category 3: 85% RAP (85% RAP, 15% VA) - Category 4: 95% RAP (95% RAP, 5% VA) The effect of mixing and compaction temperatures at 5°C, 20°C and 32°C and how cement at 0%, 1% and 3% OPC influenced the CAEMs was also investigated. This study presents a practical mix design procedure to act as a guideline for CAEMs incorporating high RAP contents by identifying critical parameters for the various categories of CAEMs which stemmed from the fact that currently there is no universally accepted mix design. The proposed mix design guideline is presented in this thesis. The effect of accelerated curing was investigated to study the effects of temperature, curing duration, conditioning and the influence of cement on the CAEMs. The research showed that an increase in curing temperature results in an increase in the stiffness and strength of the CAEMs. The thesis presents results on the mechanical and performance properties which provided vital information on expected performance of CAEMs incorporating high contents of RAP for use as a road base material. The research was able to highlight the purported effects of residual binder in RAP which could contribute positively to the mechanical and performance properties of the CAEMs. This points to the fact that treating RAP as “black rock” is not the right approach. The RAP needs to be evaluated for its inherent properties and suitability for purpose. The stiffness and strength were investigated using the Indirect Tensile Stiffness Modulus (ITSM) and Indirect Tensile Strength (ITS) tests which proved useful in ranking them. The addition of 1% OPC improved the stiffness of Categories 1-3 mixtures by 32% with Category 4 having the highest increase at 89%. The inclusion of 3% OPC, more than doubled the stiffness values. The Indirect Tensile Fatigue Test (ITFT) was used to investigate the fatigue characteristics. Results showed that if the CAEMs with cement at 1% and 3% experienced strains in the region of 200µε, they tend to fail suddenly soon after crack initiation due to reduced flexibility of the CAEMs. This was more pronounced for the CAEMs at 3% OPC. Resistance to permanent deformation was investigated using the Vacuum Repeated Load Axial Test (VRLAT) which showed that the mixing and compaction temperature influenced the permanent deformation characteristics of the CAEMs. Increasing OPC content to 1% for Categories 2 and 3 resulted in a decrease in permanent strains of 47% and at 3% OPC, the decrease in permanent strains was 54%. Wheel Tracking Test (WTT) was conducted to ascertain the susceptibility of the CAEMs to deform under loading, investigate crack propagation and number of cycles to failure. The test showed that the performance of the specimens was affected by the test temperature. Increased test temperatures resulted in an increased rate of rutting and eventual failure of the specimens. The test further highlighted the positive benefits of adding cement to the mixtures which resulted in reduced strains and an increased number of cycles to failure for the CAEMs. Structural design and modelling was conducted using KENLAYER which was able to account for the non-linearity of the CAEMs. This was crucial in having a total overview of these mixture types. Although, the structural design was based on practical hypothetical layer thicknesses, the results provided useful insight into the structural capabilities of the CAEMs. The RAP CAEMs generally had lower horizontal tensile strain values in comparison to the VA CAEMs. The design charts showed that an increase in the thickness of the base course and surfacing layer resulted in an increase in the overall fatigue life of the pavement structure. Overall, evaluating the complete findings of this research, CAEMs produced with high RAP contents especially at 50% and 85% RAP had considerably enhanced mechanical and performance properties and are suitable for inclusion as a base material for reconstruction and rehabilitation.

Roads form a key element for the expansion of economy and development of a country. As with most countries, Brunei Darussalam has been facing a rapid development to meet the economic growth that requires an efficient road network. Therefore, the scarcity of conventional road aggregates in Brunei Darussalam means that the country has a strong dependence on imported aggregates from overseas to construct quality roads. Further restrictions on local road specifications make it almost impossible to include low quality granular materials. The study reported in this thesis was undertaken on the basis that the dependence on overseas resources is not a viable long- term solution. The research task has been, therefore, to ascertain the quality of local sandstones for road construction and then to propose means to upgrade their performance quality for optimum utilisation in cost effective applications. This study focused on the road base layer since that is where most aggregate is used. The approach used for this study was to identify the common rock in Brunei Darussalam and review the candidate treatment methods. A weighted matrix for these candidate treatment methods was constructed to determine the overall ranking with selected key criteria on the basis of the local climatic condition, construction preferences and traditions. From the reviews, Foamed bitumen was selected as a feasible treatment method that can improve the sandstone characteristics under local conditions. Three curing conditions were adopted in this study, simulating extreme field conditions in Brunei Darussalam, to characterise the mechanical properties of foamed bitumen stabilised sandstone mixtures, termed 'foam mix'. The following tests were conducted: • The response of stiffness modulus behaviour in the foam mix produced at different levels of mixing moisture content and cement content under dry and wet conditions was measured to study the mixing moisture content (MMC) in foam mix design. • A humid curing study was performed to indicate the short term stiffness of foam mixes in order to aid in the prediction of the delay necessary before a road comprising these foam mixes could be opened to traffic, and to determine how curing time and moisture content affect the development of stiffness modulus with and without cement. • A preliminary investigation was carried out into the potential of coir fibres as a reinforcement agent in the foam mix, measuring its effect on stiffness modulus, tensile strength and permanent deformation. • Being sensitive to moisture, the climatic durability of foam mix was further assessed by studying the effect of dry/wet cycles on the stiffness modulus incorporating other additives such as hydrated lime and pre-blended bitumen with wet fix. • Microscopic analysis has been undertaken as a guide to characterise the microstructure of the foam mix incorporating additives such as cement and coir fibres in order to support the laboratory findings. The laboratory results confirmed that the stiffness behaviour of the foam mix could be influenced by the amount of MMC, cement content and humidity of the environment. It was found that the foam mix with 1% cement (by mass of dried aggregates) at MMC, 70% of OMC, produced a durable mixture with a high stiffness modulus value in both dry and wet conditions as well as when subjected to the effect of alternate dry and wet cycles. The investigation on the potential of coir fibre to reinforce the foam mix indicated that the fibre did help to prevent large cracks in the foam mixes but unfortunately the reinforced foam mixes were easily damaged under a wet environment.

The generic term Warm Mix Asphalt (WMA) refers to a variety of bituminous mixtures, which are produced through specific technologies, at temperatures approximately 15°C to 70°C lower than the typical production temperature range of conventional Hot Mix Asphalt (HMA) (i.e. 135°C to 160°C). The lower production temperatures of WMA offer a sustainable and environmental-friendly alternative to HMA via reducing the fuel consumption and greenhouse gas emission. Application of asphalt involves mixing, hauling, placement and compaction. As a general rule for HMA, if, during delivery and compaction, the mixture’s temperature drops below the minimum allowable production temperature at which adequate compaction can be achieved, then significant reductions in the performance of the resultant mixture is expected. In the case of WMA, it is expected that the effects of cool compaction on the properties and performance of the mixture will be less easily described than in HMA. This is due to the complicating presence of additives, which may modify the chemical, rheological and mechanical properties of the bitumen, as well as modifying the surface energy of both bitumen and aggregate, all of which can, consequently, affect the properties and performance of the resultant WMA mixture in a complex way not directly comparable to HMA mixtures. The overall goal of this research has been to investigate the effects and implications of temperature decline on the mechanical performance of WMA mixtures, produced in two different ways, included a ‘wax/organic additive’ technology (using a Fischer-Tropsch paraffin wax) and a ‘chemical additive’ technology (using a cationic surfactant liquid), along with determining the fundamental reasons for such effects. For this purpose, a devised comprehensive matrix of laboratory tests was performed on the produced wax-modified and chemical-additive-modified binders in order to provide the mechanical and rheological characterisation of the binders as well as their surface energy properties. The associated wax-WMA and chemical-additive-WMA, also different reference HMA mixtures were fabricated via mixing at recommended and adequate temperatures (according to the standard or the additive supplier’s advice) and compacting at a declining series of temperatures using two different compaction methods (i.e. gyratory compaction and roller compaction). A devised comprehensive set of laboratory tests was then carried out to fully characterise the manufactured WMA mixtures and their counterpart reference HMA mixtures via studying and understanding the influence of reduced production temperatures on their mechanical performance characteristics, including volumetric properties, stiffness modulus, fatigue resistance, rutting potential and viscoelastic behaviour representatives (complex stiffness modulus). The binder-aggregate dry bond strength of the various binder and aggregate combinations used in the asphalt mixtures was evaluated using the surface energy calculations combining the surface energy properties of the different binders and aggregates (pure and modified). Moreover, a mechanical assessment test was performed on different coating samples of the various binder and aggregate combinations to evaluate the binder-aggregate adhesive or binder cohesive tensile strength in different mixtures. The results show that compaction at lower temperatures does not have a considerable effect on the performance of asphalt mixtures, whether they contain additives or not, unless it occurs below 100°C (i.e. 80 and 85°C), in which case, in spite of some limited negative influences on asphalt performance, overall behaviour still remains in acceptable ranges. Moreover, it seems that overall, additives increase the sensitivity of asphalt mixtures’ properties to production temperatures variations. It was also found that gyratory compactors compact asphalt mixtures to a certain density regardless of the temperature (and probably material) because they are, in effect, strain-controlled. Thus, the compaction process in a gyratory compactor is widely insensitive to temperature. Therefore gyratory compaction is not a suitable method for investigating the performance of compaction site that imposes a fixed or set vibratory stress.

Moisture damage of the asphalt mixture is defined as the loss of strength, stiffness and durability due to the presence of moisture (in a liquid or vapour state) leading to adhesive failure at the aggregate-bitumen interface and/or the cohesive failure within the bitumen or bitumen-filler mastic. The presence of moisture can accelerate the distress of asphalt pavement in several different modes, such as rutting, fatigue cracking, thermal cracking and the formation of potholes. In the field, the moisture damage normally happens first at the interface of two pavement layers or at the bottom of pavement layers and develops gradually upward. Once moisture has come into contact and interacted with the asphalt mixture, moisture damage could be developed by the following mechanisms: detachment, displacement, spontaneous emulsification, pore pressure, and hydraulic scour. It should be mentioned that moisture damage is not limited to only one mechanism but is the result of a combination of several mechanisms. As mentioned previously, the common modes of moisture damage of asphalt mixtures are a loss of adhesion between the aggregate and bitumen and/or a loss of cohesion in the mixture. Among these two failures, the adhesive failure is recognised as the main mode of moisture damage. Hence, the physico-chemical interactions between aggregates and bitumen in the presence of moisture are believed to partially govern the moisture sensitivity of asphalt mixtures, which can also affect the serviceability, performance and durability of the asphalt pavement. This thesis describes the work that was carried out with regard to the moisture damage evaluation of aggregate-bitumen bonds through different procedures. The fundamental properties of the individual material such as the chemical composition and rheological properties of bitumen, moisture absorption, surface morphology and mineralogical composition of aggregates were first characterised. Two types of equipment, namely the dynamic contact angle (DCA) analyser and dynamic vapour sorption (DVS) system were used for determining the surface energy of the bitumen and aggregates, respectively. The obtained surface energy results were then combined thermodynamically to determine the work of adhesion between aggregate and bitumen, and the reduction in the adhesive properties if water is introduced into the system. Three established mechanical tests consisting of the standard peel test, Pneumatic Adhesion Tensile Testing Instrument (PATTI) test and a pull off test were developed and redesigned to make sure that these tests are practical, reliable and feasible to measure the bonding strength of aggregate-bitumen combined specimens. The composite substrate peel test (CSPT) was developed to prepare composite substrates using crushed coarse aggregates as a more practical replacement for the aggregate substrates prepared from aggregate boulders. Finally, the moisture damage results from mechanical tests and thermodynamic results were compared and correlated with the basic physico-chemical properties of the original materials. The results showed that in the dry condition, all techniques used in this research, including the mechanical tests and the surface energy tests led to similar results, with bitumen rather than aggregates dominating the bonding properties of aggregate-bitumen systems. After moisture conditioning, the four mechanical tests, including standard peel test, CSPT, PATTI test and pull-off test showed similar moisture sensitivity ranking and failure surface results demonstrating the good correlation between these four tests. In addition, based on the comparison conducted, the four mechanical tests are all considered to be reliable to evaluate the moisture sensitivity of different aggregate-bitumen systems. However, based on the aggregates considered in this research, the moisture sensitivity parameters obtained from the surface energy tests are suggested unreliable to evaluate the moisture sensitivity of aggregate-bitumen systems.

Standard techniques of random vibration analysis have been applied to the problem of determining the response of vehicle components to random road surface undulations. A simple road classification method, which will typify the general terrain inputs to vehicles is proposed and is based on the knowledge of the spectral density of any 1ongitudinal track. Finally, this work introduces a novel technique for simulating in the laboratory the response of a. vehicle to road profile excitation. Three analytical models of increasing complexity are used to describe the road surface roughness. The first considers the road as consisting of a cylindrical surface which can be defined by means of a single longitudinal track of (x), treated as a member function of a Gaussian random process.

This thesis investigates the impact of precipitation on the UK motorway network, with the aim of determining how speed, flow and accidents are affected. Climate change impact assessments require detailed information regarding the impact of weather in the current (baseline) climate and so this thesis seeks to address gaps in knowledge of current precipitation impacts to better inform future climate impact assessments. This thesis demonstrates that whilst precipitation does impact on traffic speeds, there is no universal significant single factor relationship. Indeed, a key threshold is identified at 0 mm hr-1 – the fastest speeds occur when there is no precipitation and speeds immediately decrease at the onset of precipitation. More detailed findings indicate the impact can be detected in both speed and maximum flow across much of the network as well as a downward reduction in the overall speed – flow relationship. In addition to speed flow, the impact of precipitation on road traffic accidents was also investigated. Fifteen percent of accidents in the UK occur in wet weather. Precipitation related accidents are shown to have a prolonged impact on the road network and can continue to cause a decrease in traffic speed and flow for up to three hours afterwards. With increased instances of heavy precipitation predicted as a result of climate change, these findings highlight the subsequent impact on journey speeds, travel times, traffic flows and the associated economic costs.

The author of this thesis deals with the issues of real time traffic management in junction areas and bottleneck sections on mainline railways in the event of service disturbances. A systematic methodology is proposed for modelling and solving real time train rescheduling problems in junction areas and bottleneck sections, including train re-sequencing and train re-timing. A formal mathematical model, the Junction Rescheduling Model (JRM) is proposed, based on a Mixed Integer Programming (MIP) to minimise a Weighted Average Delay (WAD). An innovative algorithm based on Differential Evolution algorithm, named DE_JRM is proposed for solving real time train rescheduling problems formulated with JRM. The performance of the algorithm DE_JRM has been evaluated with a stochastic method based on Monte-Carlo simulation methodology. The evaluation results show a good performance for both flyover and flat junctions compared with First Come First Served (FCFS) and a conventional ARS strategy. The author also extends the proposed methodology, including JRM and the algorithm DE_JRM, to model and solve real time train rescheduling problems for bottleneck sections of railway networks. Finally, an integrated system architecture for the traffic management and train control is introduced for system implementation of the proposed methodology of train rescheduling in junction areas and bottleneck sections on mainline railways.