Nondestructive Integrated CT-XRD Method for Research on Hydrated Cement System

Abstract

A nondestructive integrated CT-XRD method has been developed and used to study hydrated cement system. In this research, a beam line (BL) at the third-generation synchrotron radiation facility, SPring-8, in Japan, was used. First, X-ray computed tomography (CT) was employed to obtain three-dimensional (3D) images and select a region of interest (ROI) in a given plane section of the hardened cement paste. Then, X-ray diffraction analysis (XRD) was conducted on the specified region. These operations were implemented in situ without the removal of specimen from the stage inside the BL. The hardened cement paste was precracked and then leached by continuous water flow through the specimen, and the integrated CT-XRD method was conducted before and after the leaching test. In this way, the change in the hydrated cement system was characterized over time using the same specimen. CT observation provides the location of cracks and air voids as well as high and low density substances present in the hydrated cement system. ROI is arbitrarily determined at a set of coordinates at which one likes to evaluate the change in the cement system using XRD. This newly developed technique enables the evaluation of the presence of calcium hydroxide (portlandite) over time and space.

Advancing Concrete Durability Research through X-ray Computed Tomography

“…A non-destructive integrated computed microtomography and X-ray diffraction (CT-XRD) method was developed in 2013, and since then, the CT-XRD system has been improved while being applied to explore new aspects in the hydrated cement system of concrete (Sugiyama et al 2014;Takahashi and Sugiyama 2016). This innovative measurement system is constructed in the beamline of 28B2 at SPring-8 in Japan.…”

“…Non-destructive integrated CT-XRD method was used to investigate the alteration of cracked cement paste due to flowing water (Sugiyama et al 2015). Ordinary Portland cement (OPC) paste was used in this study.…”

“…This will explore new applications of nano-CT and micro-CT as being integrated with other spectroscopic techniques such as X-ray microbeam diffraction map-Fig. 33 Identified rich zones of portlandite (left) and calcite (right) based from CT-XRD analysis (Sugiyama et al 2015).…”

“…Fig. 32 Results of non-destructive integrated CT-XRD analysis of cracked cement paste subjected to leaching (Sugiyama et al 2015).…”

Application of non-destructive integrated CT-XRD method to investigate alteration of cementitious materials subjected to high temperature and pure water

“…This study aims to investigate the effect of carbonation on high temperature alteration behavior and the change of microstructure of fire-damaged concrete before and after immersion in pure water by using newly micro-tomographic method called nondestructive integrated CT-XRD method [11]. Powder X-Ray diffraction (XRD) was conventionally utilized to identify the cement hydration system before and after heating [12,13].…”