| 摘要 |
<p>A hollow building element (10) of plastics material comprises one or more hollow ducts (22) and has at opposite sides thereof coupling members (24, 26), whereby elements may be connected to each other directly or indirectly, wherein the ducts are generally rectangular and formed between generally flat bottom and top walls (12 and 18 respectively) and vertical end (14) and intermediate (16) walls. <IMAGE></p> |
