Q.: Please explain how the surface texture of a cast-in-place structural concrete wall can be made to match the surface texture of curtain walls made of precast panels.

A.: Trying to match exactly the texture of a surface cast vertically with that of a surface cast horizontally is a difficult, if not hopeless, task. The two surfaces, by the very nature of their construction, will be different in appearance. There are, however, ways of sidestepping this problem. One solution would be to site-precast the structural walls horizontally and then tilt them up vertically. Another method, depending on the surface pattern to be duplicated, is described in our June 1981 issue, page 495.

In this case, the construction of an addition to the Arizona Biltmore Hotel in Phoenix, concrete tiles were precast with the specified surface design and then fastened by metal anchors to concrete block walls. A similar example is in progress now--the construction of a 1-story addition onto the A. T. & T. Long Lines & Data Center in Atlanta. The original structure was built with precast panels with a ribbed surface texture. Casting new structural walls having the ribbed design themselves, in the hope of matching the existing precast finish did not promise success. Consequently, 6-inch-thick fascia panels are being precast and mechanically attached to the 8-inch-thick cast-in-place structural walls of the new structure. In both of these cases precast panels act as architectural veneer--for either concrete block or cast-in-place structural walls.