A Study on Application of Supercritical Water Treatment to Segregated Recovery of Asphalt Pavement Intended for Use as Aggregates in Cement Concrete
By Keiki Yamamoto, Noboru Yuasa, Isamu Matsui and Shoichi Akiba

Concrete Research and Technology
Vol. 19. No. 1. Jan. 2008 (Issue 46)


Synopsis:
Supercritical water, a solvent with a very high decomposition efficiency, is especially applicable to waste treatment, requiring no organic solvents or incinerators. This paper discusses the technology to remove asphalt from the asphalt mixture by using Supercritical water aS well as the promising applications of the recycled aggregates for the manufacture of cement concrete. In this experiment, the strength and durability (drying shrinkage, carbonation and freezing and thawing) tests of concretes using recycled aggregates produced by supercritical water treatments were conducted to evaluate the applicability of the aggregates to cement concretes. The results reveal that the strength and carbonation behavior were similar to using virgin aggregate, however, the drying shrinkage and the scaling of the concrete with high water cement ratio tended to increase as compared to the use of the virgin aggregate.
Keywords:
Supercritical water, Segregated recovery, Asphalt pavement, Recycled aggregate, Recycled concrete

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