Curing time effect on compressive strength and incremental leaching rates of Cs-137 and Co-60 in cement immobilized sludge

Abstract

In this experiment, after 180 days of measuring, the compressive strength development for various curing histories was investigated with particular regard to the influences of curing time points with the incremental leaching rates of Cs-137 and Co-60 from evaporator concentrates. For this purpose, three different compositions and different points of curing time were considered with an individual interval of 30 and 60 days, under the reference curing condition of 20 degrees C. In this paper we also prove that increasing the amount of bentonite causes a significant reduction in the leaching rate, because of its good sorption characteristics and ion selectivity. The results presented in this paper are examples of results obtained in a 25-year concrete testing project which will influence the design of the engineer trenches system for a future central Serbian radioactive waste storing center. (C) 2006 Elsevier Ltd. All rights reserved.