Properties of Bolt-Grouting Mortar Modified with Mineral Bauxite by Chemical Activation
Publication: Journal of Materials in Civil Engineering
Volume 28, Issue 8
Abstract
In this paper, the authors study the properties of cement-based bolt-grouting mortar that has been modified by adding mineral bauxite and gypsum. The results showed that when the bolt-grouting mortar consisted of approximately 12.5% bauxite and gypsum with a 1.0% addition of Portland Cement Association (PCA) type 4 (polycarboxylate superplasticizers), with a water-binder ratio equal to 0.3, it had the ideal properties, including a setting time between 0.5 and 1.5 h. The expansion rate on the 3rd day was larger than 0.09%, and the long-term expansion rate after 28 days stabilized at around 0.18%; the values of compressive strength at the 3rd and 28th days reached 34 MPa and 68 MPa, respectively. The maximum pullout load measured on a 1-m-long specimen on the 14th day was 71 and 87 kN. The hardened mortar was dense, as expected. The microanalysis using mercury intrusion porosimetry (MIP) and X-ray diffraction (XRD) showed that the total porosity of hardened mortar was less than 2.5%. There were plenty of ettringite crystals in the hardened paste, which was found to be able to endure steadily for a long period of time. The properties of cement-based, bolt-grouting mortar can be significantly improved by adding mineral bauxite and gypsum.
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Acknowledgments
The authors greatly acknowledge the financial support from the State Key Laboratory of Materials-Oriented Chemical Engineering with Grant No. KL10-07; supported by Jiangsu Provincial Key Laboratory of Inorganic and Composite Materials with Grant No. Wjjqfhcl200802; and by the China Postdoctoral Science Foundation–funded project (2014M562586).
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Published In
Journal of Materials in Civil Engineering
Volume 28 • Issue 8 • August 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Apr 9, 2015
Accepted: Dec 3, 2015
Published online: Mar 11, 2016
Published in print: Aug 1, 2016
Discussion open until: Aug 11, 2016
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