The paper sludge which is generated during paper manufacturing processes is incinerated to reduce its volume, and then the paper sludge ash is produced. The greater part of the paper sludge ash has been disposed to landfills and an effective utilization of the paper sludge ash has not been promoted. From view point of the effective utilization of industrial wastes, the authors have proposed that the granulated materials made of the paper sludge ash are used for concrete aggregate and evaluated the applicability of paper sludge ash to concrete. The concrete using the granulated paper sludge ash is lighter, and its water absorption is much higher than those of ordinary concretes. The drying shrinkage strain is larger than that of ordinary concretes.
The lightweight precast materials used for such as forms have a merit of the cost reduction of transportation and construction. In this study, the applicability of the mortar using granulated paper sludge ash for aggregate (PS mortar) to precast lining form is examined. Firstly, the flowability and the strength of the PS mortar are examined and the curing performance of the PS mortar form is indirectly evaluated by measuring strength and air tightness of back filling concrete. Secondly, the drying shrinkage of the PS mortar is measured and its prediction equation is proposed. Finally, Practicality of the PS mortar to precast materials is evaluated by observing deformation and crack occurring of the precast PS mortar walls constructed tentatively in this study. From results of the above examinations, it is found that the PS mortar form has a high curing performance. However, the PS mortar may not be unconditionally utilized because its drying shrinkage strain is relatively large.
