Reinforced SCC one-way slabs: time-dependent flexural cracking control

Fibre-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines the positive aspects of the fresh properties of self-compacting concrete (SCC) with the improved characteristics of hardened concrete as a result of fibre addition. To produce SCC, either the constituent materials or the corresponding mix proportions may notably differ from conventional concrete (CC). Therefore, it is vital to investigate whether all the assumed hypotheses about CC are also valid for SCC structures. This paper reports a study in which eight SCC and FRSCC slabs of similar cross-section were monitored under service loads for up to 240 d. The recorded time-dependent cracking and deflections are presented. The steel strains within the high-moment regions, the concrete surface strains at the tensile steel level, deflection at the mid-span, crack widths and crack spacing were recorded throughout the testing period. The experimental results show that the instantaneous crack widths and spacings for the normal SCC slab series were close to and much less than, respectively, the corresponding variables for the normal CC slab series.