When it was constructed in the early 1960s, Monash University’s Robert Menzies Building was considered to be an excellent example of ‘cutting edge’ architecture and construction. Indeed, it is one of the few buildings remaining in Melbourne to have been constructed using the ‘lost form precast’ method of construction, where precast concrete panels are bolted to a steel frame and then used as the ‘formwork’ for poured insitu concrete. Affectionately dubbed the ‘Ming Wing’ (after the late Sir Robert Menzies’ not-so-kind nickname ‘Ming the Merciless’) the 12-storey main building has been home to the University’s Arts faculty for over 45 years. Unfortunately, over those years, the building’s façade has succumbed to the passage of time and out-dated construction practices and was suffering significant damage and deterioration - predominately as a result of corrosion within the steel reinforcement. Ian Godson, Managing Director with specialist remedial engineers Ian Godson and Associates Pty Ltd, explained:
“While the building remained structurally sound, its façade was suffering from chloride attack and as a result there was a significant amount of damage to the spandrel panels – both in terms of spalling, and delamination of the green surfacelayer. In addition, a number of the longitudinal mullions were also showing signs of deterioration and damage caused by corrosion of the cast-in-place lifting ferrules.”
“Interestingly, while this type of ‘chloride attack’ damage is most commonly found in buildings and structures located near marine environments, the damage in the Robert Menzies Building can be largely attributed to the use of calcium chloride as aset accelerator in the concrete, which was common practice at the time,” he added.
Repair and protection works across the façade form part of 6-year, $65 million refurbishment plan by the University to completely rejuvenate this landmark building. While there can be no doubting the size and complexity of the project, the façade repair and protection works were made significantly easier, thanks to the use of a range of highperformance concrete repair and protection products from BASF Construction Chemicals.
Once the loose concrete was removed from the damaged sections, the exposed reinforcing steel was coated with Barrafer® A, a passivating primer that provides permanent protection for reinforcing steel against corrosion. Depending on the extent and/or type of damage, the damaged areas were then repaired using either Barra® Mortar HL with MCI (a cementitious, trowel-applied, lightweight polymer modified repair mortar for high build applications) or Emaco® S88C with MCI, a cementitious, trowel-applied, shrinkage compensated structural repair mortar. Both repair mortars also contained an added Migrating Corrosion Inhibitor to further protect against corrosion.
Once the physical repairs were made, the precast spandrel panels were sprayed with a coating of Protectosil CIT, a silane-based hydrophobic impregnant with an integrated corrosion inhibitor. Sprayed directly onto the surface of steel reinforced concrete structures, Protectosil CIT combines a penetrative silane treatment for the control of moisture and chloride ion ingress with advanced organofunctional corrosion inhibition in a single product, thereby significantly reducing application costs.
The final stage of the repair works involved the application of BASF’s Masterseal® 160D to the façade’s spandrel panels. Specifically developed to provide protection for concrete, mortar, masonry, natural stone or wood against aggressive environmental attack from carbon dioxide and chloride ions, Masterseal® 160D delivers the ideal combination of protection and aesthetics. The product is available in a wide range of standard colours or as a custom ‘colour-matched’ coating.
In keeping with the heritage order requirements for the Robert Menzies Building refurbishment, the Masterseal® 160D used on the project has been colour-matched to the building façade’s original dark green colour.
For further information please contact: Andrew Sarkady, Business Manager, Australia – Repair Systems and Grouts, BASF Construction Chemicals Australia Pty Ltd, Phone: (03) 9567 7300 or Email: andrew.sarkady@basf.com
About BASF Construction Chemicals
BASF’s Construction Chemicals division is the leading supplier of chemical systems and formulations for the construction industry. Continuous innovation and tailor-made solutions ensure its customers are more successful. Its Admixture Systems business unit specifically helps customers in the ready-mix, precast and manufactured concrete industries. The Construction Systems unit offers a wide range of products for sports and industrial flooring, external renders and wall insulation, expansion joints, wood preservatives as well as specialist repair mortars, tile adhesives and waterproofing membranes. The division operates production sites and sales centers in more than 50 countries and achieved sales of €2.2 billion with approximately 7,500 employees in 2006.
About BASF
BASF is the world’s leading chemical company: The Chemical Company. Its portfolio ranges from chemicals, plastics, performance products, agricultural products and fine chemicals to crude oil and natural gas. As a reliable partner to virtually all industries, BASF’s high-value products and intelligent system solutions help its customers to be more successful. BASF develops new technologies and uses them to meet the challenges of the future and open up additional market opportunities. It combines economic success with environmental protection and social responsibility, thus contributing to a better future. BASF has approximately 95,000 employees and posted sales of €52.6 billion (approximately $66.1 billion) in 2006. Further information on BASF is available on the Internet at www.basf.com