Q.: I don't understand the use of construction joints in exposed aggregate walks. What is the proper way to install them?
A.: Construction joints are located wherever operations are suspended long enough so that a cold joint would result. Construction joints are installed in the same way as in other flatwork. ACI Committee 302 published a "Guide for Concrete Floor and Slab Construction" in the June 1980 issue of Concrete International. Section 2.3 of the Guide discusses construction joints.
The Guide ACI 302.1R-80, is now available as a separate publication for $17.95 ($12.95 to ACI members) from the American Concrete Institute, Box 19150, Detroit, Michigan 48219.