HomeAmerican Codes
3D Render American Canadian GeneralIm-Export
Environmental Reinforced Concrete
Recommended max. stresses at service load for max. 12 inch bar spacing

1. Expansion Joints:
  a). ACI504R for joints guidance.
  b). They are movement joints used to allow for expansion and contraction of concrete, during the curing period and service.
  c). For walls and super-structures, the spacing of joints is from 50 ft to 250 ft.
  d). For base slabs, the spacing of joints is up to 600 ft.
  e). Normally, spacing of joints <= 120 ft, for spacing > 150 ft, the restraint exerted on the base slab by the soil should be investigated.
  f). Rebars should terminate 2 inch from the face of the joint.
  g). Rubber waterstops permit greatest joint movement and last indefinately when kept in a dark and humid environment. the thickness > 3/8 inch , the width > = 9 inch.
  h). Polyvinyl chloride waterstops permit less movement than Rubber, and less sensitive to light and drying out. the thickness > 3/8 in. , the width > = 9 inch.
  i). Sealant: nonsag and self-leveling sealants.
  j). For the end of joints, the added rebars >= #3 and spacing < = 12 in. and anchored back along the normal concrete reinforcement.

2. Contraction Joints:
  a). ACI504R for joints guidance.
  b). They are movement joints to dissipate shrinkage stresses.
  c). For water-stops, the thickness > 3/8 inch, the width > = 6 inch.
  d). Full contraction joints: Spacing of joints < = 30 ft, rebars are terminated 2 inch clear of the joint,smooth dowels are provided for equal deflection.
  e). Partial contraction joints: Spacing of joints < = 20 ft, not more than 50% rebars are passed through the joints.

3. Construction Joints:
  a). ACI504R for joints guidance.
  b). They are not movement joints but for facilitating the construction.
  c). All rebars should be continued across or through the construction joints.
  d). Vertical, horizontal joints should be bonded prepared as in ACI 301, when the wall height exceeds 8 ft, new concrete should be placed on a layer of cement mortar evenly spread over the previously placed concrete.

Reference: ACI350 Environmental Reinforced Concrete
Bar Sizes
US rebars
Sanitary exposure condition
and Z
Max. Stress for Grade 60
Max. Stress for Grade 40
All sizesMember in direct tension20,000 (138) 14,000 (96)
#3, #4, #5Flexural,SEVERE exposure, Max. Z = 9522,000 (152) 20,000 (138)
#3, #4, #5Flexural,NORMAL exposure, Max. Z = 11527,000 (186) 20,000 (138)
#6 ,#7, #8Flexural,SEVERE exposure, Max. Z = 9518,000 (124) 18,000 (124)
#6, #7, #8Flexural,NORMAL exposure, Max. Z = 11522,000 (152) 20,000 (138)
#9, #10, #11Flexural,SEVERE exposure, Max. Z = 9517,000 (117) 17,000 (117)
#9, #10, #11Flexural,NORMAL exposure, Max. Z = 11521,000 (145) 20,000 (138}
Shrinkage and Temperature Reinforcement width: in. [As] = ksi fy = in.2 length: ft thick. in. the rebar in the bottom of base slabs in contact with soil may be reduced to 50% of the value of [A s]