Title: Durability of Shotcrete

Author(s): Ernest K. Schrader and Richard A. Kaden

Publication: Symposium Paper

Volume: 100

Issue:

Appears on pages(s): 1071-1102

Keywords: admixtures; air entrainment; concrete durability; shotcrete; freeze-thaw durability; latex (plastic); permeability; placing; General

DOI: 10.14359/3744

Date: 4/1/1987

Abstract:
The normally high cement factors, low water-cement ratio, and good compaction of shotcrete typically produce strong, dense, and well-bonded materials when properly applied by either the wet- or dry-mix process. However, the dry-mix process is incapable of reliably, predictably, and routinely providing an adequately air-entrained hardened material that will withstand freeze-thaw cycles under conditions of saturation. Wet-mix process also has had its problems associated with conveying/pumping. Latex modifiers can be added to shotcrete that will produce a freeze-thaw durable material. The modifiers should not be used directly as a bonding agent. Very good bond can be achieved between shotcrete layers and to a concrete substrate by unmodified shotcrete placed against a surface that is near or somewhat below a saturated surface dry condition. Durability is directly related to permeability of shotcretes.