The present invention relates to a retaining wall block that is resistant to damage and wear caused by the environment and includes a chamber, which allows the flow of fill material to adjacent blocks below and above. The deterioration resistant block is generally a hollowed frame or shell of a deterioration...http://www.google.com.au/patents/US7198435?utm_source=gb-gplus-sharePatent US7198435 - Continuous chamber environment resistant retaining wall block and methods of use thereof
