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Title: New advanced shotcrete admixtures: Internal curing

Abstract

Tunnels and other underground construction projects have one of the worst curing conditions due to the ventilation that blows continuously dry (cold or hot) air into the tunnel. It can be compared with concrete exposed to a windy area. One would think that tunnels have ideal curing conditions with high humidity (water leakage), no wind and no sun exposure. However, this is not the case. MBT has developed a new system for more efficient and secure curing of wet shotcrete, repair mortars as well as concrete. Internal curing means that a special admixture is added to the concrete/mortar during batching as a normal admixture. This admixture produces an internal barrier in the shotcrete/concrete which secures safer hydration and better chemical resistance than the application of conventional curing agents. The benefits resulting from the new technology are impressive: The time consuming application and, in the case of various shotcrete layers, removal of curing agents are no longer necessary; curing is guaranteed from the very beginning of hydration; and there is no negative influence on bonding between layers. As a consequence of th is optimum curing effect, all other shotcrete characteristics are improved: density, final strengths, freeze/thaw and chemical resistances, watertightness, lessmore » cracking and shrinkage. In addition, MEYCO TCC 735 also improves pumpability and workability of shotcrete, even with low-grade aggregates. It particularly improves the pumpability of steel fiber reinforced shotcrete mixes. In combination with the MEYCO TCC system it contrives to even increase the beneficial effects of the slump killing system by further improving fiber orientation, reducing fiber rebound and thus raising toughness values.« less

Authors:
 [1]
  1. MBT Holding, Zurich (Switzerland). Underground Construction Group
Publication Date:
OSTI Identifier:
483906
Report Number(s):
CONF-9506349-
Journal ID: ISSN 1082-3530; TRN: IM9726%%299
Resource Type:
Conference
Resource Relation:
Conference: 7. conference on shotcrete for underground support, Telfs (Austria), 11-15 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Shotcrete for underground support 7: Proceedings; Klapperich, H. [ed.] [DMT, Essen (Germany)]; Poettler, R. [ed.] [Kling Consult, Krumbach (Germany)]; Willocq, J. [ed.] [Lafarge Fondu International, Paris (France)]; PB: 325 p.
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; CEMENTS; CURING; PROTECTIVE COATINGS; TUNNELS; ADDITIVES; PHYSICAL PROPERTIES; MECHANICAL PROPERTIES; CORROSION RESISTANCE

Citation Formats

Melbye, T A. New advanced shotcrete admixtures: Internal curing. United States: N. p., 1995. Web.
Melbye, T A. New advanced shotcrete admixtures: Internal curing. United States.
Melbye, T A. 1995. "New advanced shotcrete admixtures: Internal curing". United States.
@article{osti_483906,
title = {New advanced shotcrete admixtures: Internal curing},
author = {Melbye, T A},
abstractNote = {Tunnels and other underground construction projects have one of the worst curing conditions due to the ventilation that blows continuously dry (cold or hot) air into the tunnel. It can be compared with concrete exposed to a windy area. One would think that tunnels have ideal curing conditions with high humidity (water leakage), no wind and no sun exposure. However, this is not the case. MBT has developed a new system for more efficient and secure curing of wet shotcrete, repair mortars as well as concrete. Internal curing means that a special admixture is added to the concrete/mortar during batching as a normal admixture. This admixture produces an internal barrier in the shotcrete/concrete which secures safer hydration and better chemical resistance than the application of conventional curing agents. The benefits resulting from the new technology are impressive: The time consuming application and, in the case of various shotcrete layers, removal of curing agents are no longer necessary; curing is guaranteed from the very beginning of hydration; and there is no negative influence on bonding between layers. As a consequence of th is optimum curing effect, all other shotcrete characteristics are improved: density, final strengths, freeze/thaw and chemical resistances, watertightness, less cracking and shrinkage. In addition, MEYCO TCC 735 also improves pumpability and workability of shotcrete, even with low-grade aggregates. It particularly improves the pumpability of steel fiber reinforced shotcrete mixes. In combination with the MEYCO TCC system it contrives to even increase the beneficial effects of the slump killing system by further improving fiber orientation, reducing fiber rebound and thus raising toughness values.},
doi = {},
url = {https://www.osti.gov/biblio/483906}, journal = {},
issn = {1082-3530},
number = ,
volume = ,
place = {United States},
year = {Sun Dec 31 00:00:00 EST 1995},
month = {Sun Dec 31 00:00:00 EST 1995}
}

Conference:
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