Journal Published Online: 25 January 2019
Volume 8, Issue 1

Using Neutron Radiography to Quantify the Settlement of Fresh Concrete

CODEN: ACEMF9

Abstract

Specifications have been implemented for concrete bridge decks in North America that restrict the use of higher slump concrete mixtures primarily because of concerns about differential settlement and settlement cracking. However, the use of higher slump mixtures is frequently desired by contractors motivated by pumping and placement concerns. Research is needed to determine whether specifications that limit slump are appropriate for modern concrete mixtures. This article investigates plastic settlement and water movement in fresh concrete using neutron radiography. Mortar mixtures were examined with different slump values that were obtained by either varying the water-to-cement ratio (w/c) or using a high-range water reducer (HRWR). Results showed that the addition of an HRWR to improve workability in low w/c mixtures has a minor impact on plastic settlement. Therefore, results from this study suggest that specifications that limit the use of higher slump concrete mixtures to control plastic settlement cracking may require re-examination. Settlement appears to be largely related to water content.

Author Information

Moradllo, Mehdi Khanzadeh
School of Civil and Construction Engineering, Oregon State University, Corvallis, OR, USA
Reese, Steven R.
School of Nuclear Science and Engineering, Oregon State University, Corvallis, OR, USA
Weiss, W. Jason
School of Civil and Construction Engineering, Oregon State University, Corvallis, OR, USA
Pages: 17
Price: $25.00
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Details
Stock #: ACEM20180086
ISSN: 2379-1357
DOI: 10.1520/ACEM20180086