The extraction of pore fluid from concrete using a heavy liquid extraction method

摘要

Concrete has an intricate pore structure comprising pores and voids. The pore fluid is held within the pore structure of the concrete and provides the transport mechanism for aggressive ions, such as chloride ions. Pore fluid analysis is the most representative and accurate method of analysis for the investigation of ion ingress, ion egress and related phenomena. The micro-techniques necessary for evaluating the ion concentrations contained in the small amounts of fluid obtained are well established. The traditional method for the extraction of concrete pore fluid involves crushing the concrete at high tri-axial pressures (>400 N/mm~2) in specially constructed pore fluid expression devices. A novel method devised at the University fo Ulster is presented and discussed.