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2015FallShotcreteEMag

Technical Tip of heat production based on cement thickness, crete nozzleman will spray water before the Tek- calorimetry measurements for reaction time of crete Fast and will thereby quickly remove any dust CSA cement phases, slant-shear test, pulloff accumulation; or wet, regardless of temperature. tests, and time-of-set were a few of the additional These features are ideal for use by first-responders, tests also used during the project. as there is usually little time to prep the surface to After years of research, Tekcrete Fast was dev- be sprayed. It can also be used to repair bridges and eloped. Worldwide patents have been filed jointly roadways, overpasses and runways, and more. by the University of Kentucky and Minova USA Tables 1 and 2 show the average compressive Inc. Tekcrete Fast is a CSA-based, fiber-reinforced strength and flexural strength for Tekcrete Fast. material that achieves structural strengths in minutes—that is, a beam in a bag. It can be used in Equipment and Delivery Vehicle conventional, dry-process shotcrete equipment as a one-bag system. As mentioned previously, it also Development has the ability to adhere to any structural surface, We have found that there are many issues to be whether it is fractured; dusty, as the dry-mix shot- addressed in determining which shotcrete delivery Table 1: Average compressive strength for Tekcrete Fast in MPa (psi ) Specimen type Compressive strength, MPa (psi) 15 minutes 30 minutes 1 hour 3 hour 1 day 7 days 28 days Cores 17.2 (2500) 24.1 (3500) 31.0 (4500) 41.4 (6000) 55.2 (8000) 62.1 (9000) 75.8 (11,000) Table 2: Average flexural strength for Tekcrete Fast in MPa (psi) Specimen type Flexural strength, MPa (psi) 3 hours 1 day 7 days Cores 17.2 (2500) 24.1 (3500) 31.0 (4500) Sustainability of Shotcrete SSpecifiers regarding construction materials and placement strategies. “Sustainabilityustainability continues to grow as a driving force in the decision making of Owners and Sustainability of Shotcrete” is a timely and valuable resource to promote the shotcrete process and of Shotcrete educate potential clients and owners. The document can also be submitted with project bids to identify and substantiate the sustainability advantages of the shotcrete process. This 10-page, full-color brochure identifies and discusses the numerous shotcrete sustainability advantages and also includes case studies demonstrating these advantages in both new construction and repair. The brochure’s content was originally developed by the ASA Sustainability Committee for use in the United States Green Concrete Council (USGCC) book titled The Sustainable Concrete Guide—Applications. The full book can be ordered from www.concrete.org. Copies of “Sustainability of Shotcrete” can be ordered by calling (248) 848-3780 or from the ASA website at www.shotcrete.org. For orders outside of North America, please contact ASA directly. Order Code: SUTAIN Single copies: ASA Members: $4.95 Nonmembers: $6.95 Bundles of 10 ASA Members: $39.95 Nonmembers: $54.95 Bundles of 25 ASA Members: $69.95 Nonmembers: $99.95 40 Shotcrete • Fall 2015


2015FallShotcreteEMag
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