Abstract
Test were performed for influences of impurities contained in mixing water for concreting which are natural or artificial water on the drying shrinkage of mortar or concrete. On the basis of the test results, consideration was made to set up a standard for examining mixing water for concreting. Test results are summarized as follows; (1) The drying shrinkage of mortar or concrete are affected remarkably by the concentration of impurities in the mixing water. (2) The concentration of 1, 000 ppm of impurities contained in mixing water is criterion for determining whether or not the water in question can be used as mixing water for concreting.
