Date

2017

Document Type

Thesis

Degree

Master of Science

Department

Structural Engineering

First Adviser

Stephen Pessiki

Abstract

This research investigates the effect of adding high atomic number photon attenuating inclusions (PAI) within cementitious grout used in post-tensioned structures. Because of its advantageous attenuation characteristics, PAI can improve void detection in the target material by increasing contrast in radiographic images. The research involved three experimental tests of grouts made with various ingredients of PAI materials; compression strength tests, bleed tests, and x-ray attenuation tests. In the grout compression tests, cementitious grout specimens were made with conventional grout as well as 10% and 20% weight fraction of PAI materials (BaCO3 and Fe2O3) and 20% of Ottawa Sand, and tested at three different ages. In the bleed tests, tubular specimens were made for conventional grout and grout made with 20% weight fraction of BaCO3, and their bleeding values were recorded up to two hours. In the radiography test, cylindrical specimens were made with concrete specimen as well as conventional grout and grouts made with 10% and 20% weight fraction of BaCO3, and they were exposed to x-ray radiation for certain different times. It was found that the tested PAI materials (BaCO3 and Fe2O3) as well as Ottawa Sand do not have an adverse effect on the grout compression strength. From the bleed tests, it was found that adding barium carbonate within grout decreases significantly the amount of bleed water, comparing to conventional grout. Moreover, it was found that adding barium carbonate within grout increases its ability to attenuate the incident x-ray radiation.

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