摘要 |
PROBLEM TO BE SOLVED: To provide a drain ditch structure constructed on a slab and capable of easily and surely preventing finish mortar of a bottom part of the drain ditch structure from rising, and a concrete form fixing member.SOLUTION: A drain ditch structure A is constructed by placing protective concrete 4 on a water-resistant layer 2 provided on a slab 1 so as to form a groove forming part 3 on a predetermined position, and placing finish mortar or concrete 5 on the bottom part of the groove forming part 3. The finish mortar or concrete 5 placed on the bottom part of the groove forming part 3 is made to bite into the protective concrete 4 on both sides. The finish mortar or concrete 5 is prevented from rising in such a manner that parts 5a where the finish mortar or concrete 5 bites into the protective concrete 4 are used as anchors, even when rainwater intrudes from a clearance between the protective concrete 4 and the finish mortar or concrete 5 and creeps to the interface between the finish mortar or concrete 5 and the water-resistant layer 2. |