Curing

The concrete blocks were cured using the following procedure:

• The concrete blocks were demoulded at an age corresponding to minimum 24 maturity hours.
• Immediately after demoulding the blocks was wrapped in plastic, i.e. a thick large PE plastic bag was pulled down over the concrete block and another bag was pulled up over the concrete block. The plastic bags were secured tightly around the concrete with tape. The plastic remained on the blocks until they were placed at the exposure site in Rødbyhavn harbour (large blocks) or to core drilling for testing at 28 maturity days (small blocks).
• Each concrete block remained indoors until the block had reached minimum 14 maturity days.
• Hereafter the blocks could be moved outside if required to control maturity gain.
• The exact maturity of the concrete blocks was monitored closely using temperature sensors cast into the concrete.

The maturity of the large blocks when placed at the exposure site in Rødbyhavn harbour on April 8th 2010 was 43-49 days.

Curing of large blocks in the laboratory (left) and un-loading of large blocks at the exposure site in Rødbyhavn harbour (right).