| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the safety during walking in rain by preventing the retention of rain water on the tread of a step plate and also make the drainage easier from the step plate. SOLUTION: Artificial aggregate 3 granulated by placing fine, independent air bubbles with glass as the main component is used, and the tread on the top surface is formed by making water permeable concrete 4 which binds in a state where voids 6 are formed between the artificial aggregate. And a core member 7 with through holes 11 are embedded, and water permeable concrete penetrates rain water from exposed tread to the inside thereby permitting the drainage of rain water to the bottom surface side.</p> |
