Metal Matrix Composites (MMC) is a material which has been widely used in the aerospace and automobile industries since the 1980s, and has been classified as a hard to machine material. During the intervening years only a limited amount of research has been conducted into the cutting action of MMCs. As with traditional materials it is important to understand the wear mechanisms that contribute to tool wear reducing tool life. This review has been carried out to establish the optimum machining parameters vital to maximizing tool life whilst producing parts at the desired quantity and quality. The objective of this research is to evaluate the effectiveness of the machining parameters for these hard to machine material MMC.

No abstract

There is a need for a method for assessing the results from changes in the potential durability of road materials due to the inclusion of reclaimed and secondary component materials in the manufacture of new road materials. Such changes will have an effect on the cost of the construction maintenance, both financially to the client and environmentally to society in general, and any savings may be transitory. A site trial has been laid of mixtures with and without reclaimed asphalt and work started to assess their durability from early-life properties. The trials are being monitored for their initial performance whilstlaboratory trials are concentrating on the combined effect of ageing and moisture damage on the performance of asphalt mixtures on the trial. All three strands are being used to develop life-cycle analysis models to customise them for the effect of using alternative component materials on the availability of the network and their overall financial and environmental cost, both initial and whole-life. The costs will be identified as being direct (of the construction and maintenance) and indirect (on society in general, such as congestion).Keywords:Recycling, Secondary aggregates, Durability, Whole-life costs. RésuméIl existe un besoin de trouver une méthode pour évaluer les résultats de la variation de la durée de vie potentielle de matériaux routiers en raison de l'inclusion des matériaux de construction recyclés et secondaires dans la fabrication de nouveaux matériaux routiers. Ces changements auront un effet sur le coût de l'entretien de la construction, à la fois financièrement concernant la clientèle et de l'environnement pour la société et les économies réalisées peuvent être éphémères. Un essai du site a été fait avec des mélanges avec et sans enrobés et des travaux ont été entrepris afin d'évaluer leur durabilité et les propriétés en début de la vie. Les essais sont surveillés pour leur performance alors que les essais en laboratoire se concentrent sur l'effet combiné des dommages causés par le vieillissement et de l'humidité sur la performance des enrobés bitumineux sur le procès. Les trois brins sont utilisés pour développer des modèles d'analyse du cycle de vie pour les adapter à ll'utilisation des matériaux des composants alternatifs sur la disponibilité du réseau et leur coût global financier et environnemental, que se soit pour l'état initial que pour la vie entière. Les coûts seront identifiés comme étant directe (de la construction et de l'entretien) et indirects (sur la société en général, tels que la congestion).

Potholes are a major problem in many parts of the world. The approach to the repair of these defects is varied because they occur on different types of road and their causes can be very different. As a result, many different techniques and products are offered for the repair of potholes, all of which have advantages and disadvantages. The relative effectiveness of the different techniques and products can vary from site to site. This paper describes a Scottish study that aims to provide a consistent approach to selecting a pothole repair material or technique from treatments currently available. The new guidance is based on consultation with a range of practitioners from Scottish road authorities involved in repairing potholes. The resulting discussions and information gathering led to the development of ideas for the selection process outlined in the guide. A simple procedure utilising flowcharts has been developed to assist users to identify an appropriate pothole material or technique to treat potholes located in different situations. Whilst it is impossible to identify the unique "best" option for each situation, it is intended that the guidance will lead to the most appropriate option being selected.

No abstract