ACI 104-71 Preparation of Notation for Concrete.
f pc = compressive stress in concrete (after allow- ance for all prestress losses) at centroid of cross section resisting externally applied loads or at junction of web and flange when the centroid lies within the flange, psi. (In a composite member, f pc is the resultant compressive stress at centroid of composite section, or at junction of web and flange when the centroid lies within the flange, due to both prestress and moments resisted by precast member acting alone), Chapter 1 1 f pe = compressive stress in concrete due to effec- tive prestress forces only (after allowance for all prestress losses) at extreme fiber of section where tensile stress is caused by externally applied loads, psi, Chapter 11 f ps = stress in prestressing steel at nominal flexural strength, psi, Chapters 12, 1 8 f pu = specified tensile strength of prestressing steel, psi, Chapters 1 1, 1 8 f py = specified yield strength of prestressing steel, psi, Chapter 18 f r = modulus of rupture of concrete, psi, see 184.108.40.206, Chapters 9, 14, 18, Appendix B f s = calculated tensile stress in reinforcement at service loads, psi, Chapters 10, 1 8 f s ′ = stress in compression reinforcement under factored loads, psi, Appendix A f se = effective stress in prestressing steel (after allowance for all prestress losses), psi, Chap- ters 12, 18, Appendix A f t = extreme fiber stress in tension in the precom- pressed tensile zone calculated at service loads using gross section properties, psi, see 18.3.3, Chapter 18 f uta = specified tensile strength of anchor steel, psi, Appendix D
l dc = development length in compression of deformed bars and deformed wire, in., Chapter 12 l dh = development length in tension of deformed bar or deformed wire with a standard hook, mea- sured from critical section to outside end of hook (straight embedment length between critical section and start of hook [point of tan- gency] plus inside radius of bend and one bar diameter), in., see 12.5 and 21 .5.4, Chapters 12, 21 l e = load bearing length of anchor for shear, in., see D.6.2.2, Appendix D l n = length of clear span measured face-to-face of of supports, in., Chapters 8-11, 13, 16, 18, 21 l o = length, measured from joint face along axis of structural member, over which special trans- verse reinforcement must be provided, in., Chapter 21 l px = distance from jacking end of prestressing steel element to point under consideration, ft, see 18.6.2, Chapter 18 l t = span of member under load test, taken as the shorter span for two-way slab systems, in. Span is the smaller of (a) distance between centers of supports, and (b) clear distance between supports plus thickness h of mem- ber. Span for a cantilever shall be taken as twice the distance from face of support to can- tilever end, Chapter 20 l u = unsupported length of compression member, in., see 1 0.11 .3.1 , Chapter 1 0 l v = length of shearhead arm from centroid of con- centrated load or reaction, in., Chapter 1 1 l w = length of entire wall or length of segment of wall considered in direction of shear force, in., Chapters 11 , 14, 21 l 1 = length of span in direction that moments are being determined, measured center-to-center of supports , in. , Chapter 1 3 l 2 = length of span in direction perpendicular to l 1 , measured center-to-center of supports , in. , see 220.127.116.11 and 18.104.22.168, Chapter 13 L = live loads, or related internal moments and forces, Chapters 8, 9, 20, 21, Appendix C L r = roof live load, or related internal moments and forces, Chapter 9.ACI 104 pdf download.