3181 Accessories for concrete construction (29) Cast-in Accessories, Accessories specifically designed to be mechanically or chemically post fixed to concrete. 3182 Applied Concrete Treatment (0) Applied Concrete Treatments to improve the performance of concrete. Does not include appearance finishes or waterproofing. 3185 Concrete strengthening post construction (6) Supports, anchors, plates, brackets, panels, reinforced coatings and wraps etc for post construction strengthening system.