Sprayed Concrete Setting Acceleration Method to Reduce Standby Time until Concrete Surface Finishing
By G. Orita, Y. Kaneko, O. Makishima and A. Hirama
Concrete Journal, Vol.63, No.6, Jun. 2025
- Synopsis
- Regulations limiting overtime work in the construction industry went into force in April 2024, prompting the need for technologies aimed at improving productivity to mitigate the issue of long working hours. In particular, during cold-weather concrete work, delays in setting that extend the waiting time before surface finishing can begin are one of the causes of long working hours. To address this, the authors developed a method called the Sprayed Concrete Setting Acceleration Method, which reduces the waiting time before finishing work by 2 to 4 hours. This is achieved by sprinkling and mixing a powdered setting accelerator into the surface layer of freshly placed concrete. This paper reports the results of verification tests on the strength characteristics of concrete treated with this method, as well as the integration between the modified surface region and the untreated concrete and the durability of the resulting concrete.
- Keywords:
- Cold weather, Surface finishing, Acceleration of setting, Shortened standby time, Sprinkling and mixing
