Copyright Goodheart-Willcox Co., Inc. 290 Section 4 Construction Details The same principles of good construction should be followed in building a retaining wall as in any other reinforced masonry wall. Figure 14-27 provides specifications for building reinforced concrete masonry retaining walls up to 9′-4″ in height. Grouted Masonry Walls Grouted masonry walls are similar to reinforced masonry walls except that they do not contain rein- forcements. Grout is added to the cores in load- bearing masonry walls to provide added strength. Other uses include filling bond beams and the collar joint in a two-wythe wall. Single-wythe walls are constructed using hollow masonry units laid with face-shell mortar bedding. The vertical cores are aligned to form continuous vertical spaces that can receive grout. Two-core block are generally preferred over three-core block because of the ease of placing grout. Multi-wythe walls generally have two wythes. The wythes are spaced 1″ to 6″ apart and can be constructed of hollow or solid units depending on the building requirements. The space between the wythes can be grouted solid. Grouting is usually done as the wall is built. Goodheart-Willcox Publisher Figure 14-26. Cantilever-type retaining wall constructed of reinforced concrete block. Grade Grade 1/2" cement plaster 1 cu ft gravel 3/4" steel reinforcing 24" O.C. 12" concrete block 4" drain tile 5' O.C. 1/2" steel reinforcing Below frost depth 12" 4' 6" 6' 8" 16" Specifications for Reinforced Concrete Retaining Walls 8″ Walls Height of Wall Width of Footing Thickness of Footing Distance to Face of Wall Size & Spacing of Vertical Rods in Wall Size & Spacing of Horizontal Rods in Footing 3′–4″ 2′–4″ 9″ 8″ 3/8″ @ 32″ 3/8″ @ 27″ 4′–0″ 2′–9″ 9″ 10″ 1/2″ @ 32″ 3/8″ @ 27″ 4′–8″ 3′–3″ 10″ 12″ 5/8″ @ 32″ 3/8″ @ 27″ 5′–4″ 3′–8″ 10″ 14″ 1/2″ @ 16″ 1/2″ @ 30″ 6′–0″ 4′–2″ 12″ 15″ 3/4″ @ 24″ 1/2″ @25″ 12″ Walls 6′–8″ 4′–6″ 12″ 16″ 3/4″ @ 24″ 1/2″ @ 22″ 7′–4″ 4′–10″ 12″ 18″ 7/8″ @ 32″ 5/8″ @ 26″ 8′–0″ 5′–4″ 12″ 20″ 7/8″ @ 24″ 5/8″ @ 21″ 8′–8″ 5′–10″ 14″ 22″ 7/8″ @ 16″ 3/4″ @ 26″ 9′–4″ 6′–4″ 14″ 24″ 1″ @ 8″ 3/4″ @ 21″ Goodheart-Willcox Publisher Figure 14-27. Specifications for reinforced concrete masonry retaining walls up to 9′-4″ high.