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process included bringing an excavator to the site to charge the batch plant with sand and stone. This excavator was towed with a tri-axle dump truck also loaded with thermal insulation blankets for the job. Raw materials were delivered to the site in dump trucks where truck exhaust passed through the body to keep the sand and stone from freezing along their over-60-minute trip to the site. The material was delivered free of frozen materials and then kept from freezing with more thermal blankets while on site. SSG limited material deliveries to reduce or eliminate the amount of material that had to be kept warm overnight, if there was any left over at the end of the day. It is common practice to start using jobsite hot water heaters once the cold weather sets in, but on this job, they got lucky and there was a hot water spigot on the side of the building that they were allowed to use. The weather was accommodated by washing everything down with hot water and then covering in the sections to be shot with thermal blankets. With this process, SSG was able to keep the substrate above 40°F (4°C) before shooting began. The nonfrozen raw materials were mixed together with 120°F (49°C) water and pumped down 100 ft (30 m) of 2.5 in. (63 mm) slick line to 60 ft (18 m) of 2.5 in. (63 mm) concrete hose to another 100 ft (30 m) of 2 in. (50 mm) concrete hose. Fig. 5: Completed pool At the end of every day, all the shotcrete placed that day was covered in thermal blankets, along with what was planned to shoot for the following days. In addition to the cold, they also had to deal with adjacent Atlantic Ocean creating problems with a brackish ground water on the site. Many submersible pumps were running continuously throughout the project to keep the ground water levels down. Every day before shooting in the deep end, all the reinforcing bar had to be thoroughly cleaned with pressure washers to get the residual salt coating off them. They shot all 550 yd3 (420 m3) of the project in 8 shooting days. On one day, over 120 yd3 (92 m3) was installed in one shift, which was exciting considering they were not allowed to start our equipment until 7:30 a.m. and needed to stop shooting by 4:00 p.m. to allow enough time to finish, clean up, and cover everything before it got too dark. Light towers were used to help with the final finishing and cleanup, but they try not to shoot under the lights unless it is truly necessary as, by that time, the crew starts to get fatigued and the shadowing makes it a bit more difficult. The equipment for this project included a Cemen Tech portable batch truck, Cemen Tech portable cement silo, a Western Shotcrete Warrior 3050HP shotcrete pump, a CAT 315 excavator, and Gunite Supply shotcrete finishing tools. www.shotcrete.org Winter 2017 | Shotcrete 35


2017WinterShotcreteEMag
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