Title: External Repair of Cracked Grain Silos
Author(s): Michael P. Collins; Perry Adebar; Phil T. Seabrook; Daniel Kuchma; and Philip Sacre
Publication: Concrete International
Appears on pages(s): 22-28
Keywords: cracking; defects; epoxy resins; grouting; impact echo,
rehabilitation, reinforced concrete, repair, shotcrete, silos;
Reinforced concrete silos with wide vertical cracks were repaired by constructing reinforced concrete (shotcrete) jackets around the exterior of silo clusters. No repair was made to any interior silo walls, however an operational limitation was implemented to prevent overloading buttress walls between exterior silos. The new concrete was attached by hook anchors which were epoxy-grouted into the buttresses and the base slab. Compared with alternative schemes, the selected repair resulted in less disruption to the facility, and better corrected deficiencies by thickening exterior walls and providing a second layer of horizontal reinforcement near the exterior face. An extensive survey of the original silo walls using the impact-echo method revealed small cracks in the plane of the reinforcement, but no large delaminations.