Coal combustion residues valorisation:Research and development on compressed brick production

This paper presents the results of an experimental investigation on compressive strength of unfired compressed brick obtained with coal combustion residues (CCRs) produced by the Niger Coal Society. Preliminary physical and optical (XRD and SEM) characterisation of coal slag, including lixiviation tests, have been carried out. Cement powder, lateritic clayey soil and sand have been chosen as stabilizing agents for bricks. 12 dosages have been tested and about 300 bricks have been produced with a hand-operated press. Results show uniaxial compressive strengths (UCSs) ranging from 4 MPa to 27 MPa for the highest cement stabilisation ratio. UCS higher than 7.5 MPa have been observed for stabilisation with 20% of laterite +10% cement after 45 days of curing. Obtained bricks showed good mechanical resistance and low weight. No health threat has been detected for the obtained samples. Study developments are oriented towards the analysis of Pozzolanic properties of CCRs, properties of hydrated lime stabilisation, thermal properties and durability assessment.© 2012 Elsevier Ltd. All rights reserved.

Possible futures for social work with children and families in Australia, the United Kingdom and the United States

There has been considerable interest in recent years in comparing the operation of social work services to children and families internationally, particularly between Australia, the United Kingdom and the United States. Reviewing the respective policy environments and drawing on recent research experience in these three nations the author speculates as to how such services may be placed to respond to a converging agenda to tackle the high social and economic costs of social exclusion. It is argued that a conspiracy of circumstances have led child and family social work away from its more general child welfare objectives of the past and created consolidation of functions in relation to child protection work. This has left services ill prepared to play a central role within a new and resurgent child welfare agenda.