Title: Microstructural Changes Due to Alkali-Silica Reaction during Standard Mortar Test

Abstract

The microstructural development of mortar bars with silica glass aggregate undergoing alkali-silica reaction (ASR) under the conditions of American Society for Testing and Materials (ASTM) Standard Test C1260 was analyzed using scanning electron microscopy and qualitative X-ray microanalysis. Cracking in the aggregate, the hydrated paste, and the paste-aggregate interface was important in the development of the microstructure. Cracks were characterized according to their location, their relationship to other cracks, and whether they are filled with ASR gel. Expansion of the bars was approximately 1% at 12 days and 2% at 53 days. They fell apart by 63 days. The bars contained two zones, an inner region that was undergoing ASR and an outer and much more highly damaged zone that extended further inward over time. Evidence of ASR was present even during the period when specimens were immersed in water, prior to immersion in NaOH solution.

Authors:

Shin, Jun-Ho ^[1]; Struble, Leslie ^[1]; Kirkpatrick, R. ^[1]

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+ Show Author Affiliations

1. Univ. of Illinois, Urbana, IL (United States)

Publication Date:

Tue Dec 01 00:00:00 EST 2015

Research Org.:

Univ. of Illinois at Urbana-Champaign, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1240599

Grant/Contract Number:  

FG02-07ER46453

Resource Type:

Accepted Manuscript

Journal Name:

Materials

Additional Journal Information:

Journal Volume: 8; Journal Issue: 12; Journal ID: ISSN 1996-1944

Publisher:

MDPI

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; alkali-silica reaction; backscattered electron imaging; silica glass; ASTM C1260; microcracking; microstructure