Alkali Reactivity of Construction Spoil Gravel from Qingdao Jiaozhou Bay Subsea Tunnel
Abstract: Nowadays, a huge amount of concrete has been used as main construction material. This as a consequence will consume a large quantity of natural aggregates which quantity is not limitless. On the other hand, for instance, in the tunnel construction, a lot of spoil rocks could be produced. It will be beneficial both from the aspect of economy and ecology if these spoil rocks could be used as concrete aggregates. In this case, the alkali reactivity of the spoil aggregates will have to be determined to avoid the potential reaction between aggregates and cement. In this contribution, the spoil aggregates from Qingdao Jiaozhou Bay Subsea Tunnel have been used to prepared concrete specimens. And their alkali reactivity has been determined by swelling test. The results indicate that the swelling rates of all specimens made by spoil aggregates, both from 6 different places in underground part and from 13 places in subsea part of the Tunnel, are at most 0.08 %, which is not higher than the limit value of 0.1 % according to the standard. This means the tested spoil aggregates do not have potential alkali reactivity, and they can be used as concrete aggregates.
J. Gao et al., "Alkali Reactivity of Construction Spoil Gravel from Qingdao Jiaozhou Bay Subsea Tunnel", Applied Mechanics and Materials, Vols. 94-96, pp. 1391-1394, 2011