Abstract
Cementitious material coating work is frequently executed to repair agricultural use open concrete channels. However, spatial distribution of the neutralization depth of the cementitious material coating work caused by usage environment have not been clarified. It can be important basic information for planning the survey point and the sample size of a monitoring survey. This paper reports results of a multi-point investigation of the neutralization depth of cementitious coating works three years after execution. The results show that neutralization depths followed a normal distribution, and coefficient of variation was 20-40%. Neutralization depth at the side wall of the channel was larger above the water surface than that under water. Further, based on those results, it was estimated that 9 or more samples are required in order to obtain a 95% confidence level and 20% tolerance in evaluation of neutralization depth.
