Amerimix SI 600 Core Fill Grout is designed for load bearing masonry construction as weel as vertical or horizontal reinforcing. The preblended bagged product offers batch-to-batch consistency and improved jobsite efficiency with either 3,000 or 5,000 psi coarse or fine design mixes. Amerimix SI 600 is available in 3,000-lb. bulk bags or 80-lb. bags and conforms to ASTM C476, ASTM 1019 and ACI 530.