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deteriorated substructure and required them to be 3/8 in. (10 mm) river rock. Safety, time, and in place until the specified 14-day compressive quality all significantly contributed to the very strength tests of the shotcrete was met. The use successful use of shotcrete by the Chicago Depart- of shotcrete and its versatility had many advan- ment of Transportation (CDOT) on “The 606” tages over form-and-place. One advantage was project. The general contractor and the subcon- the ability to remove the shoring towers long tractor are also proud of their safety record of zero before the 14-day compressive strength require- accident reports while working in one of the most ment when the pre-bagged shotcrete material congested parts of the city. All work was done to reached 70% of its strength. This allowed for OSHA regulations and CDOT environmental reopening the streets in compliance with the City requirements. All of the compressive strength test of Chicago’s permit requirements. Another advan- results exceeded the specification’s requirement tage in using shotcrete was repairing the retaining and the shotcrete solution resulted in a long-term, walls adjacent to private backyards, including that affordable repair with minimum impact on the of a well-known chef. ACR staged the shotcrete surrounding community. equipment on the opposite side of the trail and ran the shotcrete hoses up and over the trail as opposed to through the yard and gardens. In addi- Kevin Doyle graduated from tion, this set-up eliminated the need for tradesmen The Ohio State University in to access the yards to set-up and strip formwork 2009 with a bachelor’s degree for a form-and-place operation, thus completely in construction management. preventing the damage or inconvenience that Having worked for a privately access could create. Using the shotcrete method owned government contractor also meant that there was no possibility of a form out of college, Doyle gained the blowing out during casting and damaging the experience from the owner’s yard. The shotcrete process also allows a visual perspective that would prove valuable once he confirmation of encapsulation of the reinforcing joined American Concrete Restorations, Inc., in bar throughout the shotcrete placement process, April 2013. Doyle brought his understanding of while cast-in-place work requires casting into a the necessity for strong communication and team- closed form where incomplete consolidation and work between a contractor and owner to this resulting voids aren’t evident until stripping the project and helped to ensure project progress forms. After the shotcrete was placed, a double remained on track. “The 606”-Bloomingdale layer of curing compound was applied, thus Trail is his first major project in which he helped eliminating the need to impede on private prop- manage, and thus Doyle is extremely proud that erty for any form removal, grinding, or patching. it has been awarded ASA’s 2014 Outstanding3The scope of work resulted in over 15,000 ftRepair and Rehabilitation Project.3) of removal and replacement with high-(425 m quality shotcrete. All the shotcrete was placed by ACI-certified Nozzlemen employed by a qualified The Outstanding Repair shotcrete contractor. The shotcrete was placed & Rehabilitation Project with a 0.42 water-cementitious materials ratio, along with the addition of 10% by weight of Project Name 606-Bloomingdale Trail | Viaduct Repairs Project Location Chicago, IL Shotcrete Contractor American Concrete Restorations, Inc.* General Contractor Walsh Construction Architect/Engineer Transystems Material Supplier/Manufacturer SPEC MIX*, Putzmeister Shotcrete Technology* Project Owner City of Chicago—Department of Transportation *Corporate Member of the American Shotcrete Association 34 Shotcrete • Winter 2015


2015WinterShotcreteEMag
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