Ecology blocks are concrete blocks made from leftover or unused concrete. Instead of dumping out unused concrete that is otherwise wasted, companies cast these blocks in 1-square-yard or half-square-yard sizes. Full-size ecology blocks weigh between 3,000 and 4,000 pounds each, and half-blocks weigh between 1,500 and 2,000 pounds.
Half-size blocks are 2 feet by 2 feet by 3 feet, and full-size versions are 2 feet by 2 feet by 6 feet. Rebar is placed in these blocks in a curved shape at the top for easier lifting with chains. Cranes and backhoes must have 4,000 pounds of lifting capacity to ensure ecology blocks are lifted into place properly.