I am going to use Quickcrete's Cement based Non Shrink Precision Grout for a Pre-Cast Communications Vault and Lid I am making. The vault is 4x6x4. 3" thick Side Walls. I am adding 25#'s of 3/8" Pea Rock to each 60#pound bag of Grout per the instructions to keep its High Strength Properties. The reason I want to use this is because 9500#PSI 65.5 MPa 3 day Strength and its flow-ability. I will be adding 1/2 fiberglass rebar to the precast for strength as well. I talked to Quickcrete and they said it could be done. Let me know your thoughts.