Experimental characterization of interstitial pore pressure in concrete under high confinement

Overview & Synopsis

This study focuses on measuring the pore pressure of concrete under high confinement. When concrete structures are subjected to an impact loading, material exhibits high triaxial compressive stresses which are highly influenced by the saturation ratio. In order to measure the interstitial water pore pressure inside the concrete under mechanical loading, a new experimental device was developed. Usually, specimens of 14cm in length and 7cm in diameter are tested using the GIGA press. In the new concept, the specimen length is reduced to 8cm and a pore pressure measurement cell of 6 cm in length is incorporated. The cell has micro-holes on its upper face, so that, when the specimen is loaded water pressure is transmitted from concrete to the cell where a cylindrical sensor equipped with a gage is placed. Preliminary results indicate that concrete pore pressure increases up to 200 MPa during an hydrostatic test at 300 MPa of confinement.