From Bridges and Ferry Terminals, to Waste Water Treatment Plants and Transfer Stations, Metro's crew is well versed in the variety of complications associated with working around the public, dealing with various scheduling issues – and in confined, sometimes hazardous spaces.
We pride ourselves in our ability to come up with solutions that work well for our clients and our crew that meet or exceed expectations.
Metro Concrete Restoration was the successful bidder on a Metro Vancouver project out for tender last year to do concrete repairs on the Cleveland Dam Spillway, as well as coating the training walls. The work is planned for April- October 2018. The project is located in North Vancouver at the south end of Capilano Lake. Project cost is $2 million. This project has a number of challenges that our team needs to overcome. Not the least of which is access.
Stage one and two includes coating the walls of the spillway with a cementitious waterproofing material, both inside, and outsides of the walls. When possible MCR will partner with Pacific Ropes who specialize in high angle rope access. The few areas that their crew won’t be able to access, man baskets from cranes will be used to access the repair locations.
Stage three includes concrete repairs at the top of the spillway just under the drum gate.
One of the other concerns is the environmental containment to ensure that no contaminated water, debris, or construction material ends up in the fish bearing river below the dam. TRI Environmental will be onsite to provide environmental monitoring.
All of the work needs to fit within a finite schedule and is dependent on lake levels which changes with weather and snowpack melt. Capilano Lake supplies approx. 40% of Metro Vancouver’s drinking water. It will be our goal to complete the work requiring the spillway to be dry during the month of August when lake levels are naturally below the spillway level, allowing us to work uninhibited by water leakage on the spillway.
WASTE WATER TREATMENT PLANT
The sewage treatment plant of a major metropolitan city required us to go into each of thirteen pre-aeration holding tanks. The covers installed over these tanks trap H2S gas between the effluent water and the covers. The H2S gas reacts with the exposed concrete, creating sulphuric acid which degrades the cement paste.
The repair work was conducted in a confined space and within a biohazardous work environment. We implemented a detailed confined space entry work program with full-time air monitoring and active ventilation to ensure the safety of our crew.
We found that hydro demolition with a 20,000 psi hydro unit was the most effective method of exposing a sound substrate. Once all the deteriorated concrete has been removed, a 50 mm x 1200 mm shotcrete repair is applied to the prepped surface.
The value was between 2.5 and 3 million dollars.
We have been involved in a variety of water reservoir projects required to decrease the amount of water leaking and being wasted. One reservoir required work due to deteriorated joints and concrete edges caused by extended time of fresh water leaching of the cement particles from the concrete surface. Another reservoir had poor initial workmanship from leaving shotcrete rebound around the bottom edges, creating easy passage for water to leak out.
Our team has been able to assess the problem, assemble the required procedures needed to fix the problem, and subsequently carry out the work required to greatly decrease the amount of water leaking from these reservoirs.
FERRY TERMINAL - RE & RE OF TOPPING ON TRANSFER DECK
Metro preformed work on the transfer decks of a well-used ferry terminal that had multiple cracks and spalls. The deck is subject to a large amount of stress caused by the weight it holds on an everyday basis. Metro removed and replaced the topping for the berth 3/4 transfer deck and scissor ramps. Jeene® joints were also installed at key slab joint locations to facilitate expansion/contraction movement to increase the lifetime of the structure.