CT Measurements of SAP Voids in Concrete

Published

August 15, 2010

Author(s)

Sara Laustsen, Dale P. Bentz, Marianne Hasholt, Ole M. Jensen

Abstract

This paper describes how X-ray computed tomography (CT) scanning can be used to determine the void distribution in hardened concrete. Three different approaches are used to analyse a binary data set created from CT measurement. One approach classifies a cluster of connected, empty voxels (volumetric pixel of a 3D image) as one void, whereas the other two approaches are able to classify a cluster of connected, empty voxels as a number of individual voids. Superabsorbent polymers (SAP) have been used to incorporate air into concrete. An advantage of using SAP is that it enables control of the amount and size of the created air voids. The results indicate the presence of void clusters. To identify the individual voids, special computational approaches are needed. The addition of SAP results in a dominant peak in two of the three air void distributions. Based on the position (void diameter) of this peak, it is possible to calculate the liquid absorption of the SAP within the fresh concrete. This estimated liquid absorption is in agreement with measurements carried out in previous studies.

Proceedings Title

Use of Superabsorbent Polymers and Other New Additives in Concrete

Volume

PRO 74

Conference Dates

August 15-18, 2010

Conference Location

Lyngby, DK

Pub Type

Conferences

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Keywords

Air voids, Concrete, Superabsorbent polymer, X-ray computed tomography

Citation

Laustsen, S. , Bentz, D. , Hasholt, M. and Jensen, O. (2010), CT Measurements of SAP Voids in Concrete, Use of Superabsorbent Polymers and Other New Additives in Concrete, Lyngby, DK, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=906106 (Accessed October 11, 2025)