existing precast channels, dated 1958
 

existing precast channels, dated 1958
i am reviewing an existing structural drawing dated 1958. the first floor system is constructed of a one-way, precast concrete channel slab system (10" deep with a 2" concrete topping). the channels are shown to be spaced approximately 2'-6" on-center. the drawings also designate the concrete members as lc-5's, lc-6's, and lc-8's.
i am searching for the design capacity of these existing members. is there a reference guide with design tables for these particular members?