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A complete and detailed analysis of the microstructural development during ageing in an 8090 (Al-2.3Li-1.2Cu-1Mg-0.1Zr) alloy, an 8090/20wt%SiC p MMC, an Al-1.5Li-Cu-Mg MMC and an Al-Cu-Mg MMC (all with similar Cu and Mg contents) has been performed. Volume fractions of all precipitates relevant for precipitation strengthening of the alloys (δ' phase, S' phase and GPB zones) have been determined using a recently derived method based on differential scanning calorimetry (DSC). The volume fractions have subsequently been successfully fitted using a novel model for transformation kinetics. The sizes of these precipitates have been analysed using newly derived expressions consistent with the latter model. As a result of dislocation generation around misfitting SiC particles the volume fractions of both GPB zones and S' phase depend strongly on the presence of these particles. Also the amount of Li present in the alloys influences the volume fractions of the phases significantly. The sizes of S' are similar for the four alloys. Introduction AimsMonolithic Al-based alloys for structural applications are generally strengthened by 4 basic mechanisms: precipitation strengthening, solution strengthening, grain and subgrain strengthening and strengthening by dislocations. The first two mechanisms depend strongly on composition of the alloy and on heat treatment and are generally employed in a metastable state, whilst the latter two mechanisms depend mostly on thermo-mechanical processing routes. In metal matrix composites (MMCs) additionally load transfer to ceramic inclusions in the matrix can increase the strength of the alloy (see e.g. [1,2]). Apart from this direct effect the presence of ceramic inclusions will also influence the precipitation in the matrix [1,3,4] and thus influence strengthening in an indirect way. The main aim of the present work and the companion paper [5] is to derive and validate a complete microstructure-property model for reinforced and unreinforced Al-Li-Cu-Mg type alloys and link this model with a novel model for the kinetics of microstructure development.

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Trenchless technologies (TT), unlike open cut trenching, offer the potential to install, maintain and refurbish buried utilities without the need to close long stretches of carriageway. Recent studies indicate that carbon emissions associated with trenchless installations are far smaller, and trenchless installations are more sustainable, than trenching. Yet utility companies, and their contractors, routinely shun trenchless technologies due to the perceived risk of damaging previously undetected third party assets. Mapping the Underworld (MTU) seeks to create a multi-sensor tool, and a new philosophical approach to underground mapping, to mitigate such risks and facilitate the routine adoption of TT. The novel approach is now being developed through the proof of concept stage towards field trials and the results of these proving trials form the basis of this paper. Moreover such street works, like all construction, repair, renewal and maintenance projects, must be reviewed in terms of a sustainability assessment framework to explore their real costs and benefits to the society on behalf of which, as ultimate 'users' of the facilities, the works are being carried out. This paper seeks to integrate the findings of a highly multi-disciplinary technology-based project with a wider research programme on the context of effective and efficient working in the streets. The lessons drawn from this programme of research extend to all aspects of pipeline engineering. ICPTT 2011