Grout for Reinforced Masonry

Grout for reinforced masonry is reviewed through national product specifications and national masonry standards and codes. The role of grout and the factors affecting grout performance lead into a review of ASTM Specification for Mortar and Grout for Reinforced Masonry (C 476-71). A critical review of the specification shows that provisions for grout design, materials, and testing are deficient or nonexistent. Past and present research on grout for reinforced masonry was reviewed and found deficient. Early research allowed measuring the bond of grout to reinforcing steel. Material changes warrant further testing. Recent grouted masonry testing shows grout compressive strength per se is a poor indicator of the interaction of grout in masonry. Research areas deemed essential include grout mix design, grout placement, and grout physical properties of equal or greater significance than compressive strength.