2016 Volume 70 Issue 1 Pages 378-383
The reconstruction support road which connects Morioka and Miyako pass through a cold snowy region. To ensure the scaling resistance of lining concrete of tunnel on this line, the laboratory and site tests have been conducted to direct the mix designing. The results of lab tests show that the hardened concrete with the 7.0％ air content in fresh condition has the good scaling resistance. Moreover, by using the simulation samples the effect of fine aggregate ratio has been studied in site test. It indicates the water cement ratio must be decreased while the air content rises to 7.0％ to ensure the strength of construction. In that case, the increasing of fine aggregate ratio can ensure the air content of hardened concrete and, the improvement of scaling resistance of concrete has been attained.
