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Crack-resistant cement–bentonite cut-off wall materials incorporating superabsorbent polymers

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Chen, J 
Al-Tabbaa, A 

Abstract

jats:p Preserving the integrity of cement–bentonite cut-off walls, particularly in aggressive environments, is critical to their serviceability in polluted sites. The hardened cement–bentonite material in cut-off walls is highly susceptible to desiccation and wet–dry cycles, commonly leading to cracking. The objective of the work presented in this paper was to develop crack-resistant cement–bentonite cut-off wall materials subject to wet–dry cycles. Superabsorbent polymers (SAPs), which are cross-linked polymers that can absorb and retain a large amount of water and swell as a result, were employed for this purpose. It is found that the added SAPs increased the compressive strength by decreasing the water-to-cement ratio and that the strain at failure also increased due to energy dissipative and reinforcement effects. In addition, crack resistance was greatly improved under the imposed wet–dry cycles as the matrix suction was reduced as a result of the reduction of the contact between the free pore water and cement–bentonite particles and the increase of the pore size in the matrix. The morphology and microstructure of the interconnected foam network formed by the SAP films in the matrix were identified with SEM-EDX and micro-CT scan analyses. The results demonstrated the significant potential for SAPs in the development of crack-resistant cement–bentonite cut-off wall materials. </jats:p>

Description

Keywords

cement-bentonite, crack resistance, superabsorbent polymer, wet-dry

Journal Title

Canadian Geotechnical Journal

Conference Name

Journal ISSN

0008-3674
1208-6010

Volume Title

58

Publisher

Canadian Science Publishing

Rights

All rights reserved
Sponsorship
Engineering and Physical Sciences Research Council (EP/P02081X/1)