Bridges

Self-compacting concrete (also known as Super-workable concrete in Australia and Self-consolidating concrete in North America) is defined in EN 206 Part 9: Additional Rules for Selfcompacting Concrete (SCC) as concrete that is able to flow and compact under its own weight, completely fill the formwork with its reinforcement, ducts, box outs etc, whilst maintaining homogeneity. A study on self-compacting concrete was conducted by RTA Bridge Engineering for the possible use of SCC in certain reinforced and prestressed concrete bridge elements where mechanical compaction is hindered by OHS requirements and often times not practically feasible to assure a homogeneous concrete end product. Self-compacting concrete is considered as an improvement on the current applications of high or very high slump flowable concrete. This paper will discuss the conducted study that includes laboratory mix design trials, full scale field trials and the project verification trials. The study resulted in the preparation of draft clauses for the inclusion of SCC in the next major amendment of the RTA QA Specifications B80 – Concrete Work for Bridges (RTA B80).