Bonding old and new cement-bonded masses - with older core exposed and subjected to intervening cement slurry layer

摘要

The process is for bonding together two masses containing cement of different ages, such as flooring being laid on a hard-set concrete base, where firm adhesion is usually difficult to attain, with hollow-sounding spaces left at various points. The core of the older hard-set mass is exposed by chemical or mechanical means. An intervening layer composed of a cement slurry is then applied, and the new cement-bonded mass is immediately applied to this fresh layer, which may be of fine cement slurry or plastic and cement slurry. The core is mechanical and exposure may be by means of high-pressure water.