Phi factors or resistance factors for grout bond strength

The specs sheet I am looking at for my grout suggests a bond strength of 1500 psi after 28 days. In order to check whether this is good for my factored demand (LRFD), I would like to know what resistance factors can I apply to the bond strength or which code/design manual could I find that in. My demand bond strength is 603 psi, so that allows me to go up to 0.4 (1500/600) phi factor, but anything less than 0.4 will not work.