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2016FallShotcreteEMag

ASA President’s Message Elevated Training Over the past few weeks, I found myself in an array of diverse venues within the world of shotcrete. My first job duty took me 1000 ft (300 m) below surface elevation, just under the Hudson River to review a fiber-reinforced shotcrete application. We were doing underground, job-specific training for crew and nozzlemen working By Bill Drakeley on a shaft lining of a water tunnel. The project is using a proven mixture as its concrete material, which must follow a slow and narrow route before being delivered to the hopper. The following day, I was being deposed as an expert witness against a high-volume pool contractor in a large class-action suit involving nearly 20 pools with substandard shotcrete placement. Lastly, I flew across the country to give a presentation on how, in terms of water retention, wet- and dry-mix shotcrete can be used in lieu of cast-in-place and may, in some cases, have a superior bond to its properly prepared substrate. Why do I mention my recent activities? Well, as I stood in a shaft hole below the mighty Hudson River, I began to contemplate the quality of my immediate surroundings, as well as in the shotcrete industry as a whole. To be frank, one wrong move in the confined shaft I occupied could have led to injury or worse. As an expert witness, I wondered how one contractor can do things so wrong for so long and still be considered a viable shotcrete contractor. Quality and safety go hand in hand. While giving my presentation, I asked myself and the audience why many quality field applicators, engineers, and specifiers of concrete shy away from the shot product and its ideal placement methods in exchange for a straight-cast box or tank. One seemingly simple explanation to these questions is quality training, or lack thereof. Those reading this article already understand that industry training needs to be elevated and promoted. ASA does its job for its members. Speaking with the Executive Committee and our Executive Director, Charles Hanskat, we have noticed a considerable jump in technical questions asked by the public regarding swimming pools. In my opinion, this is a direct result of the Pool & Recreational Shotcrete Committee’s Position Statements on proper applications and the best practices for pool shotcrete placement. With this information publicly available on the web and in wide circulation, more consumers are questioning their contractor’s practice if it deviates from our written positions. The new ACI 506R-16, “Guide to Shotcrete” (prepared by ACI Subcommittee 506-C, Shotcreting-Guide, chaired and assembled by ASA member Lars Balck), aligns with ACI 506.2-13, “Specification for Shotcrete.” The coordination between the two documents lets the new Guide serve as a descriptive commentary to help explain the terse requirements of the Specification. These documents act as additional sources of reference on industry shotcrete, and along with other supporting ACI/ASA documentation, make up a comprehensive library of basic “how-tos” on proper placement. The fact that the available technical data is either very slow to disseminate or does not reach those in the field is a problem. We must encourage companies or individuals who have the goal of becoming an educated and well-versed shotcrete applicator to start with the program being developed by the Contractor Qualification Committee. This committee aims to establish key identifiers in determining contractors’ NForce-Fiber® for Performance & Sustainability. Developed by Industry Professionals, Tested by Industry Experts. For the First Time, a Shotcrete Fiber for not Only MIX STABILITY, COHESION, ADHESION, REBOUND & CRACK CONTROL... but A PERFECT FINISH!!! Effective in BOTH Wet and Dry Shotcrete. Technical Info / Expert Reports: www.canadiangreenfield.com Contact: info@canadiangreenfield.com 4 Shotcrete • Fall 2016


2016FallShotcreteEMag
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