Reported in this paper are the results from a study carried out to investigate the quality of concrete cast using slit steel form. Such forms are made of steel and have well-ordered slender ceramic coated slits. Since surplus water and air can escape through these slits, the concrete cast using slit steel form has increased strength, an improved performance in shutting off corrosion promoting materials, such as carbon dioxide and chloride ions, reduced permeability and absorption of water, etc.. Further the use of slit steel shuttering reduces “pockmarking” on the surface, which is of special importance in the concreting of tunnel linings. This paper includes the results of the field application of this type of shuttering in the lining concrete for shield tunneling.

View full abstract

Recently, in railway bridge crossing over roads, there are many cases that are restricted to height of girders. In that case, through type girder bridges are ordinary employed. A new construction system of the precast prestressed concrete through type girder bridge is discussed, and it is consist of main girders and slabs that are erected as precast members and combined with prestressing strands on site. In this system, the cost and time of construction can be saved. The design method and construction process of the system are described and the confirmation test results of scaled-model of the bridge are reported.

View full abstract

[in Japanese]

View full abstract