World-wide globalization of aircraft transportation has promoted to construct new airports or to expand current airports for aiming a status of hub airport in regional areas. As airport requires huge area space for facilities, some of recent airports are constructed on a reclaimed land at coastal area. Relatively large ground settlement may take place after opening of airport due to consolidation in soft ground. In order to mitigate the adverse settlement effect, the Up-Lift Method was developed in which PC slabs are lift up and grouting material is injected in openings beneath the pavements for compensating the ground settlement. The strength and deformation characteristics of the grouting material should be precisely designed to assure safety trafiic of aircrafts.
　In several years ago, some PC pavements were severely damaged where the grounting material was broken into pieces and squeezed up onto the pavement by repeated aircraft passings. The authors conducted a series of cyclic loading tests to investigate the cause of the damage and develop the countermeasure, while the breakage of the grouting material similar to that found in-situ was observed in
several test cases. Based on the observations in the tests, new grouting materials are developed to assure the sufficient strength, even though they are injected into the water remained beneath the PC slabs. In this article, a series of the cyclic loading tests on the current grounting materials and on the new-developed grouting