Abstract
Recently, the amount of waste materials such as muds obtained from construction and/or hedoro obtained from dredging, has been increasing according to increasing demands of construction as a results of industrial development, economic growth and need for constructing better environments. It is, therefore, very important to use them as construction materials, from the viewpoint of natural resource preservation and environmental impact mitigation.
The main purpose of this paper is to present a method for improving properties of hedoro soils by using cement group hardening materials added with CAS materials and gypsum, and to clarify the utilizing feasibility of the hedoro soils for construction materials.
As a result, it is found that the strength of the treated hedoro is affected by water content, grain-size characteristics and the clay minerals in hedoro, and reduces due to the existance of humic acid. However, the hardening effect is magnified due to cement group hardening materials added with CAS reagents and gypsum. Especially, the strength appearance in an early age is remarkable. It is concluded that the treated hedoro can be applied as subgrade, embankment and so on. Furthermore, it is clear that Ettringite, which is considered as the dominant reaction product, contributes to the development of strength of hedoro.
