Refining Design Deformation Predictions by Improving Concrete Volume Stability Assessment

Project Member(s): Li, J., Castel, A., Baweja, D.

Funding or Partner Organisation: Queensland Department of Transport and Main Roads (Queensland Dept of Main Roads Consultancy Funds)
BG&E Pty Ltd
BG&E Pty Ltd
Smartcrete CRC
Smartcrete CRC

Start year: 2023

Summary: On all projects that use concrete as a material, serviceability management is critical particularly for controlling movement and managing cracking. A critical factor in assessing and designing for serviceability (material movement) is concrete shrinkage, which is in part covered in Australian Standards and guides. Shrinkage is critical in estimating movement and potential cracking in commonly used structural elements such as columns, beams and walls, and particularly slabs (including base pavement layers). Standards such as AS5100.5 (Bridge Design – Concrete) and AS 3600 (Concrete Structures) give guidance on shrinkage. However, provisions are based on research that is over 30 years old mainly considering General Purpose (GP) cement concretes with limited focus on Supplementary Cementitious Materials (SCMs). It is now common practice of replacing cement with high volume of SCMs such as fly ash and granulated blast furnace slag (GBFS) to reduce the embodied CO2 of cementitious products in Australia. In addition, emerging SCMs such as calcined clays and other manufactured pozzolans are likely to be introduced in the Australian market because fly ash production in Australia is predicted to reduce drastically due to the shift from coal burning energy to renewable energy. As the binder composition governs for a large part concrete shrinkage, AS5100.5 and AS 3600 provisions for shrinkage are out of date and require revisions. In this project, recent data for concrete shrinkage will be collated and design requirements for key concrete structural elements in relation to shrinkage will be evaluated (covering slab-on-grade, suspended slabs and column elements). Improved models for linking actual structural movements to shrinkage-based data will be established and validated.

FOR Codes: Construction materials, Cement and concrete materials

Acknowledgement of Country

UTS acknowledges the Gadigal people of the Eora Nation, the Boorooberongal people of the Dharug Nation, the Bidiagal people and the Gamaygal people, upon whose ancestral lands our university stands. We would also like to pay respect to the Elders both past and present, acknowledging them as the traditional custodians of knowledge for these lands.