The Background
Brisbane’s popular City Reach Boardwalk which runs along the Brisbane River from the City Botanic Gardens to Howard Smith Wharves has undergone a $7 million refurbishment in order to extend its service life. The first stage of maintenance work (between 145 and 175 Eagle Street) included replacing deck panels, patch repairs and sealing concrete to eliminate further corrosion. The second stage focused on two sections of the bridge at Admiralty Quays and River Place Apartments. This stage involved repairing and replacing the concrete deck slabs that support the suspended bridges and repairing piles and beams under the boardwalk.
The Challenge
Brisbane City Council’s warranty required a single source supplier that could provide a complete repair system for the maintenance work needed on the boardwalk. The complete repair system installation for the deck soffit, which also included fiber reinforced polymer (FRP) strengthening, was required to be completed in seven days. On top of these requests, project engineers requested the repair mortar to achieve 40 megapascals (MPa) before installation of the FRP laminate strip in order to take the load where prestressed strand sections were damaged.
Our Solution
Master Builders Solutions presented a specification for a complete repair system in order to meet the required program for the soffit repairs and rectification of the pile caps on the boardwalk. We also worked closely with the Brisbane City Council and their contractors to ensure that compliance with warranty requirements was met.
Project Facts at a Glance
The Brisbane City Council required a complete repair system from a single supplier
Repairs to the boardwalk pile caps and beams included installation of cathodic protection sacrificial anodes
Repair to soffit with gunite and coating the soffit with silane creme to protect from further ingress of chloride ions
Design changes eliminated the FRP, but the speed of application was still essential due to the project deadline
Product Facts at a GlanceMasterProtect 806CP is a galvanic anode that protects reinforcing steel from corrosion.
An aqueous cream, MasterProtect H 1150 impregnates concrete by stopping water ingress whilst still allowing the structure to breathe.
MasterEmaco S 5440CI, a structural repair mortar is used on concrete elements to reduce shrinkage and cracking.
MasterEmaco S 822CI is a cement-based shotcrete mix used in repairs where impressed current cathodic protection systems are used.
A product that also contains active corrosion inhibition is MasterEmaco P 500AP which can also be used as an adhesive bonding slurry.
MasterEmaco N 5200CI is a universal fast setting repair mortar best suited for environments where corrosion inhibition is necessary.
MasterEmaco N 5100 is a thin layer fairing mortar suitable for leveling uneven surfaces, filling honeycombs and pinholes.
Customer's Benefit
Easy to use ‘form and pour’ product, MasterEmaco S 5440CI was used for the pile cap repairs to re-establish original strength and structural integrity.
Ability to pack around the cathodic protection anodes with a low resistivity repair mortar such as MasterEmaco N 5200CI before placing MasterEmaco S 5440CI on the pile caps.
Master Builders Solutions recommendation of experienced dry spray applicators capable of achieving high builds, saved time in the application.
Application of MasterProtect H 1150 at thick creme consistency, eliminated the possibility of excess product dropping into and potentially contaminating the Brisbane River.