Influence of SCC on the effectiveness of controlled permeability formwork in improving properties of cover concrete

Abstract

Controlled permeability formwork (CPF) is a system proven to enhance the durability of near-surface concrete significantly during the casting process. However, the use of CPF requires vibration energy to expel the excess water and air within the concrete mix. On the other hand, self-compacting concrete (SCC), as the name suggests, does not require any vibration effort for its compaction. As a result, the effectiveness of CPF to improve properties of the cover concrete in SCC couldbe different from that of the conventional concrete. Therefore, the influence of two types of SCC on the effectiveness of CPF was studied by comparing air permeability, sorptivity, water permeability and tensile strength of the cover concrete. Test results showed that compared to impermeable formwork (IF) the use of CPF improved the permeation properties of both conventional concrete and SCC mixes. The surface tensile strength also improved in both cases. The surface formed with CPF did not have any blowholes. Therefore, it is concluded that the use of CPF for manufacturing SCC could be recommended.