To achieve the desired color and texture in exposed cast-in-place concrete surfaces, architects and engineers must specify several steps and precautions in addition to those used for structural concrete.
The key to success in specifying architectural concrete is the mock-up. There are two distinct advantages to producing a full-scale mock-up on the jobsite. The most obvious advantage is that all parties involved get a chance to see the final appearance of architectural surfaces created with the contractor's planned materials, equipment, and procedures. The second advantage is that keeping an approved mock-up on the job gives workers a reference of acceptable color and texture and may help resolve future disputes.
High density forms should be used for cast-in-place architectural concrete, and their use should be required in the specifications. Forms should be stripped completely from vertical architectural surfaces when the concrete had achieved a compressive strength of 1000 psi or 24 hours have passed, whichever is later. Any repairs that are necessary following removal of the forms should be performed in the same manner as on the mock-up.