Study of Deterioration on Tunnel Lining Concrete Using Cement Substitute Material

Abstract

This paper presents an investigation on deterioration mechanism of a tunnel lining concrete constructed in around 1928. In this tunnel, the surface area of the concrete changed in quality into a powder and became weak. It was found that diatom earth was mixed in the concrete as a cement substitute material. Investigation by using concrete specimens suggested that compressive strength of diatom earth blended concrete declined with carbonation. Study results showed that the tunnel lining concrete was deteriorated by carbonation of diatom earth contained as a cement substitute material.