Table 5.1—Dowel size and spacing for round, square, and rectangular dowels* Slab depth,
in. (mm)
Dowel dimensions,
†
in. (mm)
Dowel spacing center-to center, in. (mm)
Round
Square
Rectangular
‡
Round
Square
Rectangular
5 to 6
(130 to 150)
3/4 x 14
(19 x 360)
3/4 x 14
(19 x 360)
3/8 x 2 x 12
(9 x 51 x 300)
12
(300)
14
(360)
19
(480)
7 to 8
(180 to 200)
1 x 16
(25 x 410)
1 x16
(25 x 410)
1/2 x 2-1/2 x 12
(13 x 64 x 300)
12
(300)
14
(360)
18
(460)
9 to 11
(230 to 280)
1-1/4 x 18
(32 x 460)
1-1/4 x
18
(30 x
450)
3/4 x 2-1/2 x 12
(19 x 64 x 300)
12
(300)
12
(300)
18
(460)
*
ACI Committee 325 (1956); Walker and Holland (1998).
†
Total dowel length includes allowance made for joint opening and minor errors in positioning dowels.
‡
Rectangular plates are typically used in sawcut contraction joints.
Notes: Table values based on a maximum joint opening of 0.20 in. (5 mm). Dowels must be carefully aligned and supported
during concrete operations. Misaligned dowels may lead to cracking.
Table 5.2—Dowel size and spacing for diamond- shaped load plates (Walker and Holland 1998) Slab depth, in.
(mm)
Diamond load plate
dimensions, in. (mm)
Diamond load plate spacing
center-to-center, in. (mm)
5 to 6
(130 to 150)
1/4 x 4-1/2 x 4-1/2
(6 x 110 x 110)
18
(460)
7 to 8
(180 to 200)
3/8 x 4-1/2 x 4-1/2
(9 x 110 x 110)
18
(460)
9 to 11
(230 to 280)
3/4 x 4-1/2 x 4-1/2
(19 x 110 x 110)
20
(510)
Note: Table values based on maximum joint opening of 0.20 in. (5 mm).
Construction tolerances required make it impractical to use diamond-shaped load
plates in sawcut contraction joints.
