Study on the Recycling System of Lightweight Fiber-Stabilized Landfill Materials from High-Water Content Construction Sludge

摘要

Construction sludge is the typical high water-content mud and is produced more than 10 million ton per year from the construction sites in Japan. However, the recycling rate of the construction sludge is extremely low. Therefore, we have already developed a new recycling system of high water-content mud by using the paper debris and polymer in order to increase therecycling rate of the construction sludge. By using this system, 200-500% water content mud has been modified to the landfill materials by 20 minutes mixing process. The modified mud has several features and one of the features of the modified mud is lightweight. The fields where lightweight landfill materials are effectively applied will be as follows:1) The large scale reclaimed works:2) A tree-planting on the rooftop to prevent heat island:3) Measures works for landslides:In this paper, a concept of producing the lightweight landfill materials from the construction sludge is described. In order to use the modified mud as the lightweight landfill materials, it is very important to know the density of the modified mud. Furthermore, the estimation of watercontent is also important to use the modified mud as vegetation soils. Therefore, theoretical considerations were carried out and the models to estimate the density and water content of modified mud by using above recycling system were developed. In order to examine the accuracy of the model, the specimen were made by using the imitation mud and actual construction sludge,and the density and water content of the modified mud were measured. It was confirmed that these models are almost reasonable by comparing the estimated values and actual ones of the modified mud. By using these models, the production of lightweight landfill materials which satisfy the necessary strength and density for the construction work will be possible by adjusting the water content of initial construction sludge.