Reinforced Masonry Rebar Splice and Development Length
Design Code: ACI 530-08, Section 2.1.9.3 equaion (2-12) (ACI 530-05
also apply)
Splice and development length of rebar
Ld = 0.13*db2*fy*g
/ (K*Öf'm)
³
12" (ACI 530-08, Eq. 2-12)
Where db is diameter of rebar, fy is yield strength of
rebar, f'm is compressive strength of masonry.
K is smaller of 5db, minimum cover of rebar, and spacing between rebar
lap, and
g
= 1, for #5 bar or smaller, 1.3 for #6 and #7 bar, 1.5 for #8 to #11 bar.
Splice and development length of rebar in 8 inches concrete masonry
(inches) (fy = 40000 psi)
|
Width
of masonry wall (in)
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
|
Yield
strength of rebar fy (psi)
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
|
Bar
size
|
#3
|
#4
|
#5
|
#6
|
#7
|
#8
|
#9
|
#10
|
#11
|
|
Bar
diameter db (in)
|
0.375
|
0.5
|
0.625
|
0.75
|
0.875
|
1
|
1.128
|
1.27
|
1.41
|
|
K
= 5db or mini concrete cover
|
1.88
|
2.50
|
3.13
|
3.44
|
3.38
|
3.31
|
3.25
|
3.18
|
3.11
|
|
g
|
1
|
1
|
1
|
1.3
|
1.3
|
1.5
|
1.5
|
1.5
|
1.5
|
|
Compressive
strength of masonry f'm (psi)
|
|
|
|
|
|
|
|
|
|
|
1350
|
12
|
14
|
18
|
30
|
42
|
64
|
83
|
108
|
136
|
|
1500
|
12
|
13
|
17
|
29
|
40
|
61
|
79
|
102
|
129
|
|
2000
|
12
|
12
|
15
|
25
|
34
|
53
|
68
|
89
|
112
|
|
2500
|
12
|
12
|
13
|
22
|
31
|
47
|
61
|
79
|
100
|
|
3000
|
12
|
12
|
12
|
20
|
28
|
43
|
56
|
72
|
91
|
Splice and development length of rebar in 8 inches concrete masonry
(inches) (fy = 60000 psi)
|
Width
of masonry wall (in)
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
7.625
|
|
Yield
strength of rebar fy (psi)
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
|
Bar
size
|
#3
|
#4
|
#5
|
#6
|
#7
|
#8
|
#9
|
#10
|
#11
|
|
Bar
diameter db (in)
|
0.375
|
0.5
|
0.625
|
0.75
|
0.875
|
1
|
1.128
|
1.27
|
1.41
|
|
K
= 5db or mini concrete cover
|
1.88
|
2.50
|
3.13
|
3.44
|
3.38
|
3.31
|
3.25
|
3.18
|
3.11
|
|
g
|
1
|
1
|
1
|
1.3
|
1.3
|
1.5
|
1.5
|
1.5
|
1.5
|
|
Compressive
strength of masonry f'm (psi)
|
|
|
|
|
|
|
|
|
|
|
1350
|
16
|
21
|
27
|
45
|
63
|
96
|
125
|
162
|
204
|
|
1500
|
15
|
20
|
25
|
43
|
59
|
91
|
118
|
153
|
193
|
|
2000
|
13
|
17
|
22
|
37
|
51
|
79
|
102
|
133
|
167
|
|
2500
|
12
|
16
|
20
|
33
|
46
|
71
|
92
|
119
|
150
|
|
3000
|
12
|
14
|
18
|
30
|
42
|
64
|
84
|
108
|
137
|
Splice and development length of rebar in 12 inches concrete masonry
(inches) (fy = 40000 psi)
|
Width
of masonry wall (in)
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
|
Yield
strength of rebar fy (psi)
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
40000
|
|
Bar
size
|
#3
|
#4
|
#5
|
#6
|
#7
|
#8
|
#9
|
#10
|
#11
|
|
Bar
diameter db (in)
|
0.375
|
0.5
|
0.625
|
0.75
|
0.875
|
1
|
1.128
|
1.27
|
1.41
|
|
K
= 5db or mini concrete cover
|
1.88
|
2.50
|
3.13
|
3.75
|
4.38
|
5.00
|
5.25
|
5.18
|
5.11
|
|
g
|
1
|
1
|
1
|
1.3
|
1.3
|
1.5
|
1.5
|
1.5
|
1.5
|
|
Compressive
strength of masonry f'm (psi)
|
|
|
|
|
|
|
|
|
|
|
1350
|
12
|
14
|
18
|
28
|
32
|
42
|
51
|
66
|
83
|
|
1500
|
12
|
13
|
17
|
26
|
31
|
40
|
49
|
63
|
78
|
|
2000
|
12
|
12
|
15
|
23
|
26
|
35
|
42
|
54
|
68
|
|
2500
|
12
|
12
|
13
|
20
|
24
|
31
|
38
|
49
|
61
|
|
3000
|
12
|
12
|
12
|
19
|
22
|
28
|
35
|
44
|
55
|
Splice and development length of rebar in 12 inches concrete masonry
(inches) (fy = 60000 psi)
|
Width
of masonry wall (in)
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
11.625
|
|
Yield
strength of rebar fy (psi)
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
60000
|
|
Bar
size
|
#3
|
#4
|
#5
|
#6
|
#7
|
#8
|
#9
|
#10
|
#11
|
|
Bar
diameter db (in)
|
0.375
|
0.5
|
0.625
|
0.75
|
0.875
|
1
|
1.128
|
1.27
|
1.41
|
|
K
= 5db or mini concrete cover
|
1.88
|
2.50
|
3.13
|
3.75
|
4.38
|
5.00
|
5.25
|
5.18
|
5.11
|
|
g
|
1
|
1
|
1
|
1.3
|
1.3
|
1.5
|
1.5
|
1.5
|
1.5
|
|
Compressive
strength of masonry f'm (psi)
|
|
|
|
|
|
|
|
|
|
|
1350
|
16
|
21
|
27
|
41
|
48
|
64
|
77
|
99
|
124
|
|
1500
|
15
|
20
|
25
|
39
|
46
|
60
|
73
|
94
|
118
|
|
2000
|
13
|
17
|
22
|
34
|
40
|
52
|
63
|
82
|
102
|
|
2500
|
12
|
16
|
20
|
30
|
35
|
47
|
57
|
73
|
91
|
|
3000
|
12
|
14
|
18
|
28 |
32
|
43
|
52 |
67
|
83
|
| 