Title:
Failure of Latex-Modified Shotcrete
Author(s):
Stella L. Marusin
Publication:
Concrete International
Volume:
12
Issue:
10
Appears on pages(s):
39-42
Keywords:
bleeding (concrete); bonding; cracking (fracturing); failure; latex; shotcrete; General
DOI:
Date:
10/1/1990
Abstract:
Discusses causes of extensive cracking in latex-modified shotcrete structures due to a failure of bond between the shotcrete layers. Field and laboratory investigations showed that latex can migrate to form a polymer-rich film that hardens on the surfaces of previously applied layers and prevents proper bonding of freshly sprayed shotcrete. This film can be caused by entrapped air bubbles, bleeding during curing, applying relatively thick fresh shotcrete layers, and ambient temperature at the time of spraying. Shotcrete delamination also causes further development of cracks already present, allowing water to enter the structure. Water movement, development of crystals in the cracks, and freezing and thawing can contribute to further cracking and disruption of the shotcrete.