Commercial Building Complex

Barton Street – Stoney Creek, Ontario

Defective Construction of Load Bearing 240 mm Thick (10 in. nominal) Reinforced Concrete Block Masonry Walls

The 240 mm thick load bearing reinforced concrete block masonry walls have unrestrained heights of 5,300 mm to 6,100 mm (17 ft. 4 ½ in. to 20 ft. 0 in.). Typically, one 20 M vertical Rebar was to be installed in grouted cells of the concrete block masonry walls at 2,400 mm c/c (10 ft. c/c).

A corbel exists at mid height of the load bearing exterior walls. The corbel is offset 50 mm. The Cowie Engineering site investigation revealed the following:

1. A significant amount of vertical reinforcing steel was missing.

2. Where vertical reinforcing steel was installed it however, did not extend continuously from the bottom of the wall to the top of the wall. Typically, the vertical reinforcing steel was; (a). installed in short lengths, (b). not continuous and (c). did not extend through the corbel located at mid height of the wall.

3. In many instances vertical reinforcing steel existed within empty cells of the concrete block masonry units because of the absence of grout caused by improper grouting procedures.

4. Typically, the cells of the hollow concrete block masonry units of the corbel remained open throughout the continuous length of the corbel. The cells of the corbel should have been filled with grout.

Urgent temporary lateral stabilization (out of plane) was required for most exterior masonry walls of the building. In the interest of life safety, the walls required temporary lateral stabilization until permanent strengthening could be implemented. Cowie Engineering prepared design drawings and specifications for temporary stabilization of the exterior walls of the building.

In the interest of expediency and to avoid major disruption to the tenants of the building, most of the work was done from the exterior of the building. In general, the temporary stabilization consisted of installing vertical hollow structural steel (HSS) members extending from the foundation to the roof. The bottom of each HSS member was anchored to the foundation wall and the top of each HSS member was anchored to the roof framing. Lateral (out of plane) stability of the masonry walls was provided by chemically bonded threaded rods with anchorage to the vertical HSS members. 

Cowie Engineering provided alternative permanent restoration designs.

 



01. One storey office complex (offices in the front with storage and loading doors in the back) with a factory building located at the North end. Viewing Northwest. The exterior reinforced concrete block masonry load bearing walls were provided lateral (out of plane) restraint by the installation of chemically bonded anchors into the concrete block masonry with connection to the vertical spanning hollow structural steel members.




02. One storey office complex with their front entrances facing East. A two storey office building is located at the South end of the complex.




03. Factory building located at the North end of the complex. Viewing Northwest. 


 


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HALIFAX OFFICE
1046 Barrington Street, Suite 200
Halifax Nova Scotia B3H 2R1
(902) 422 4493

TORONTO OFFICE
c/o Konsolidated Structural
306 - 2968 Dundas Street West
Toronto Ontario M6P 1Y8
(416) 762-3224

This email address is being protected from spambots. You need JavaScript enabled to view it.


HALIFAX OFFICE
1046 Barrington Street, Suite 200
Halifax Nova Scotia B3H 2R1
(902) 422 4493

TORONTO OFFICE
c/o Konsolidated Structural
306 - 2968 Dundas Street West
Toronto Ontario M6P 1Y8
(416) 762-3224