In January 2005, the Sydney Airport Corporation Limited (SACL) issued a tender for development of buildings to accommodate commercial car parking and integrated commercial facilities on a two hectare site located in the eastern section of the existing on grade car park serving the International Terminal. Part of this major development proposal was to accommodate the Airbus A380 and provide an extension for the apron of the airport.
A tender was submitted to supply 40mm maximum size aggregate concrete having 40MPa, compressive strength and a flexural strength requirement of 4.5MPa in 28 days. The tender required a supply of 10,000m3 of concrete for the project that would be tested at high frequency to ensure compliance with the specification. Holcim supplied aggregate concrete for this project.
The testing requirements for the project were unique and were mainly due to the 40mm aggregate used in the concrete mix (non standard product). Prior to the project commencement, technical services staff worked together with production and sales personnel to discuss the project and identify problems. A major issue identified was that the Australian standard method of test for flexural strength determination required beams having dimensions of 150mm x1500mm x 550mm. This was due to the larger aggregate used in the mix design. Sourcing the steel moulds for the project proved difficult and could have jeopardised the project. Moulds were eventually acquired and trial testing was undertaken to ensure compliance could be consistently achieved.
The project initially required 48 steel moulds for trial and production assessments and would generate over 1000 test samples during the 10 to 12 week project. The samples were large and heavy. The laboratory testing the samples for flexure has a daily testing frequency consisting of handling over 500kg in weight. This job required two staff members to perform the testing and another to remove the samples from the moulds and deliver them to the laboratory for curing and testing. Significant work was also done to ensure that the variation of results was within the design requirements.
Field Technical Officers conducted site risk assessments and developed a system with the tendering company to reduce manual handling by using site-owned lifting equipment. This step reduced the cost of testing and personal risk. The project was completed on time.