Schöck ComBAR®, the only possible option…von Christian Witt
The Christie Street Bridge is located in the heart of the town of Grimsby in the Niagara Region in Ontario, crossing the CN Rail Tracks. The Niagara Region is currently rehabilitating this bridge. ELLIS Engineering Inc. has undertaken the Environmental Assessment and the detailed design and is in charge of the contract administration for this project. The General Contractor (GC) is the renowned company Rankin Construction out of St. Catharines, ON.
The parapet walls, approach slabs and parts of the deck were in need of rehabilitation. Therefore, this project called for Schöck ComBAR® glass fibre rebar to reinforce the new PL-2 parapet walls on the bridge. Since most of the bridge deck will remain in place, the vertical ComBAR® bars are to be doweled into the deck.
ComBAR® has proved to achieve the minimum bonding requirement for this project in less than 160mm embedment under test lab conditions. The embedment for this project was therefore only 200mm. Hilti Hit RE500 was used as epoxy to connect ComBAR® with the existing deck. The areas over the wingwalls will use the well known ComBAR® headed bars at the inside face of the wall.
Why ComBAR®? ComBAR® is the only Glass Fibre rebar that has a ribbed surface and assures optimal bonding between the bar and the concrete in both short and long term applications. Since the ribs are mechanically “cut”, these remain intact and do not detach from the core of the bar. Schöck has extensively tested ComBAR® for short and long term applications, considering bonding creep effects over time. After many years of development and research, Schöck and several Universities worldwide came to the conclusion, that this is the only viable way to assure a bonding behaviour that is analogous to steel rebar, where the week member is the concrete and not the bar.
The ComBAR® installation was carried out by the GC itself. The project also called for 3 field pull out tests. ComBAR® bars were tested on site up to 90 kN of pull out force (approx. 450 MPa stress in the bar). Nothing moved… ComBAR® has shown again to be a consistent product with an extremely high level of performance.
Another successful ComBAR® story. Well done ComBAR®!