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2017WinterShotcreteEMag

Fig. 4: Mesh installed using gunite hooks Fig. 5: Soaker hose creating a saturated surface-dry surface on area to be repaired In each section of wall, a vertical expansion joint was placed to full depth at approximately 15 ft (4.5 m) spacing and a horizontal joint was placed 7.2 ft (2.2 m) up from the ground to help control any potential drying shrinkage that may occur from shooting these large concrete sections. A 7-day wet cure was specified to further reduce the potential for shrinkage cracking. Perforated water dripper hoses were installed at the top of the wall and turned on once the shotcrete reached final set. The specification originally called for burlap to hang down from the top of the wall, but this was Fig. 6: Soaker hose used to cure the dry-mix shotcrete Fig. 7: Shotcrete application and finishers removed from the plan as it could also provide a climbing device for the prisoners to escape. A specific sequence had to be followed to assure that the security personnel could still see and maintain order in the prison. The walking platforms that sat on the top of the walls had to be removed section by section, allowing work on only one section of the perimeter wall at a time. An entire section of the wall had to be completed and the walking platform had to be replaced before allowing work to begin on another section. 24 Shotcrete | Winter 2017 www.shotcrete.org


2017WinterShotcreteEMag
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