Control Technology for Air Voids in Concrete Using Microspheres that Assure Freeze-Thaw Resistance
By M. Hashimoto, D. Hayashi, N. Sakata and S. Hanehara
Concrete Journal, Vol.56, No.2, Feb. 2018
- Synopsis
- In order to suppress frost damage in concrete structures in cold climates, it is effective to entrain fine independent air voids in concrete. The air voids entrained by AE agent may disappear by the time concrete hardens depending on the materials used, proportioning conditions, construction conditions, and so on, and air voids effective for freeze-thaw resistance may not be secured in some cases as a result. Hitherto, the authors have focused on "hollow microspheres" consisting of fine hollow spheres made of acrylonitrile resin and conducted experiments to determine their role in the freeze-thaw resistance of concrete. This report summarizes the findings obtained so far with respect to the use of hollow microspheres, confirms the dispersibility of such microspheres through construction experiments for actual application, and reports the results of application to an actual structure.
- Keywords:
- hollow microsphere, freeze-thaw resistance, scaling resistance, air void distribution, air void spacing factor
