|
|
Framework for judging the environmental impact to soil and groundwater An important aspect of the project is the synthesis of collected information and the development of a proposal for the evaluation of impact in different scenarios with regard to environmental quality criteria, as this is the only way to decide if alternative fuels and alternative raw materials can be accepted in view of impacts to soil and groundwater. A framework approach in environmental impact assessment to soil and groundwater has wider applicability than just concrete:
References:
The binding mechanisms of trace elements in the hardened cement paste determine the release rate and mechanisms of "dangerous" substances from cement based products. In particular the incorporation in cement phases, like the ettringite substitution of oxyanions is of relevance. In addition, the mineralogy of cement pastes is hardly relevant from an environmental point of view as surface formed minerals control the leachability of trace constituents. The pH gradient in the surface of a cement-based specimen in particular has far reaching consequences for net release due to interface precipitation. Modelling chemical speciation
In the framework of the preparations
of a new HORIZONTAL TC CEN TC 351 dealing assessment of environmental
impact under the CPD a scenario approach for different utilization
options and the life cycle stages of cement-based materials is addressed.
The approach is however generic, which implies that it is equally
relevant for blended cements, for aggregates as well as for pavement
material. A database expert system has bee developed to make access
to the currently widely scattered data easier. This database/expert
system LeachXS, which still needs further development, is now available
for users.
© Copyright 2003 by ECOserve
|
