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resulting lining is more acid- and abrasion-resistant and more impermeable than ordinary concrete. The STI custom-designed system is operated via remote control with cameras, using a “spinner” or double nozzle that uniformly sprays the material onto the surface and will fit through an opening as small as 3 ft (1 m) in diameter so no excavation is needed. A crew of three can place up to 500 ft (152 m) per day of 1 to 2 in. (25 to 50 mm) thick under normal circumstances. After the lining is in place, it is ready within hours of placement with no adverse effect on the environment. SHAFTLINING SUCCESS • In December 2015, Pan American Silver was raise boring a 2011 x 20 ft (613 m deep x 6 m wide) I.D. shaft in Zacatecas, Mexico. The upper 689 ft (210 m) was in questionable ground, so it was decided to raise a smaller 10 ft (3 m) I.D. bore, shotcrete the shaft, and then excavate from the top and down. • The day after the bore machine was removed, STI lowered a camera down and marked where 3 in. (75 mm) of shot crete was needed—a total of 240 ft (73 m) in various areas. • At 11:00 a.m., we started lining a flash coat top to bottom. We then lined 3 in. (75 mm) of shotcrete where needed and by 6:00 p.m. the same day, we had completed the shaft lining—a total of 39 yd3 (30 m3) was in place! • The STI Shaft Lining Mix was made on site using local material and an on-site batch plant. • There was no noticeable rebound and this structural shotcrete would reach 3191 psi (22 MPa) in 24 hours. Our process-oriented approach includes helping you from mixture design and specification to material handling, logistics, equipment selection, and training. Total support from the ground up! Shotcrete Technologies, Inc. 1431 Miner Street PO Box 3274 Idaho Springs, CO 80452 Website: www.shotcretetechnologies.com Phone: 303-567-4871 E-mail: info@shotcretetechnologies.com www.shotcrete.org Spring 2017 | Shotcrete 67


2017SpringShotcreteEMag
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