Advances in Computed Tomography for Geomaterials: GeoX 2010

Sealing Behavior of Fracture in Cementitious Material with Micro-Focus X-ray CT

D. Fukuda¹ — Y. Nara¹ — D. Mori² — K. Kaneko¹

¹Hokkaido UniversityKita 13 Nishi 8, Kita-ku, Sapporo 060-8628 [e-mail]

 

² Taiheiyo Consultant Corporation2-4-2, Osaku, Sakura [e-mail]

ABSTRACT. High strength and ultra low permeability concrete (HSULPC) has been studied for an alternative technology for long term confinement of Carbon14 (C-14) in geological disposal in geological disposal of transuranic radio waste (TRU waste). Thus knowledge of time-dependent fracturing and permeability is important. For cementitious materials, precipitation of calcium compound can occur on the surface. This can affect the time-dependent crack growth and permeability. In this study, the sealing behavior of cracks and pores in HSULPC submerged in water was observed by using micro-focus x-ray CT. It was shown that cracks and pores were sealed by precipitation of the calcium carbonate. Furthermore, it was shown that the sealed volume increased with increasing elapsed time and sealing rate was calculated. It is concluded that x-ray CT is useful for quantitative estimation of sealing of cracks and pores in cementitious material.

 

KEYWORDS: fracture sealing, cementitious material, micro-focus x-ray CT, image subtraction

1. Introduction

For geological disposal of radioactive wastes, the intensity ...