In this paper, the properties of the grouting material are investigated. First, laboratory tests were conducted on the material prepared in accordance with the current specification after surverying the condition of the pre-cast PC slab pavement in service. Next, the load-induced stress on the material was calculated. Finally, the possibility of new materials was examined minutely.
　As a result, the following conclusions were obtained.
1)The lack of the durability of grouting material lead to the distress such as faulting in case of the pre-cast PC slab pavement constructed earlier. The material, however, had the sufficient strength against the repeated loading of 20,000 cycles with the amplitude of 60% of the specified strength.
2)As the items required for the specification on the grouting material, the liquidity, its retaining time, strength, shrinkage and bleeding must be included. In addition, the durability in the submerged condition must be also specified.
3)New kinds of materials investigated in this study were possibly used.