Embodied carbon dioxide in concrete: Variation with common mix design parameters

The transition towards a low-carbon infrastructure requires an understanding of the embodied carbon (eCO 2) associated with concrete. However, much current work on eCO 2 underestimates the complexity of its relationship with concrete mix design. This paper demonstrates how eCO 2 of concrete is not a simple function of strength. Rather, for a given strength, considerable eCO 2 savings can be made by careful attention to basic mix design. Replacement of cement with PFA (pulverised fuel ash) can achieve considerable savings; additionally, using a concrete of lower workability, employing a superplasticiser, using crushed rather than rounded aggregate and using a higher strength of cement can have comparably significant effects. The analysis is presented in terms of embodied carbon per unit strength; this shows that there is an optimum strength for all concretes (with regard to minimising eCO 2 per unit of structural performance) of between 50 and 70 MPa

Understanding the costs of investigating coliform and E. coli detections during routine drinking water quality monitoring

Bacteriological failure investigations are crucial in the provision of safe, clean drinking water as part of a process of quality assurance and continual improvement. However, the financial implications of investigating coliform and Escherichia coli failures during routine water quality monitoring are poorly understood in the industry. The investigations for 737 coliform and E. coli failures across five UK water companies were analysed in this paper. The principal components of investigation costs were staff hours worked, re-samples collected, transportation, and special investigatory activities related to the sample collection location. The average investigation costs ranged from £575 for a customer tap failure to £4,775 for a water treatment works finished water failure. These costs were compared to predictions for US utilities under the Revised Total Coliform Rule. Improved understanding of the financial and staffing implications of investigating bacteriological failures can be used to budget operational expenditures and justify increased funding for preventive strategies

Time domain modelling in sewage treatment control

SIGLELD:1576.573(ARD--13) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Public water supplies 1991-1992 Water resources survey

SIGLEAvailable from British Library Document Supply Centre- DSC:MFE 1169(CH--93.2148)(microfiche) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Water pollution control in Scotland Recent developments

SIGLELD:GPB-2888 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Public water supplies in Scotland Water resources survey

SIGLEAvailable from British Library Document Supply Centre- DSC:6969.729(1992/93) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

The 1984 drought in Scotland Its effect on river systems and public water supplies

SIGLEAvailable from British Library Document Supply Centre- DSC:GPB-7504 / BLDSC - British Library Document Supply CentreGBUnited Kingdo