CONCRETE TECHNOLOGY L.L.C. 1- INTRODUCTION Hollow core slab which is a precast,prestressed concrete member with a continues voids provided to reduce weight and , therefore, cost and as a side benefits, to use for concealed electrical or mechanical runs Primarily used for floor or roof deck system, and panels, spandrel members and bridge deck units. 2- MANUFACTURING Hollow core slab units are casting using extrusion system, where a very low slump Concrete is forced through the machine. The cores are formed with argues or tubes with the concrete being compacted Around the cores as shown below.
FIGURE (1)
Hollow cores m anufacturing anufacturing 3-Why CT’S hollow core slab 3-1-CT’s 3-1-CT’s hollow core slab providing economical, efficient floor and roof system. The hollow core slab’s voids may be used for electrical or mechanical runs. 3-2-The 3-2-The casting of the hollow core slab units is performed by high technology procedures gives the slab a high quality and very low use of material and a very fast delivery. 3-3-The 3-3-The hollow core slab provides the efficiency of a prestressed member for load capacity , span range and deflection control. Excellent fire resistance is another attribute of the hollow core slab. Used as floor ceiling assemblies hollow core slabs have the excellent sound transmission characteristics. characteristics.
Page 1
4-Product Detail
Hollow core slab 150 mm Hollow core slab 320 mm
Hollow core slab 200 mm
Hollow core slab 400 mm
Hollow core slab 265 mm
Hollow core slab 500 mm
DIFFERENT HOLLOW CORE SLAB SECTIONS
5-structural design 5-1-Services Concrete Technology gives here the guide for you to design the hollow core slab units, but the final decision is for our experienced structural engineers whom always will be ready to assist and advise you on all matters related to the design of the hollow core slab units. 5-2-How to check your slab As the most of precast members, hollow core slab design as a simply supported slab in accordance with British standard BS110. The main structural functions of floors are span, load bearing, transverse distribution of vertical loads, diaphragm distribution of the horizontal actions as well as resistance against fire and accidental actions affecting the floor elements or the supporting structure. For guidance only concrete technology gives here curves for the slab design range and the load capacity for the varies slab thickness for varies strands on page 4 to page 7
2
LOAD CHARTS AND TABLES HCS-150mm
-For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications CURVES ARE CALCULATED USING BS8110 CODE
-Maximum service design load(qsls) in excess of slab weight in KN/m2
30
25
20 ) 2 m / N K ( S D A O L
SLAB PROPERTIES:
-PRECAST SLAB WEIGHT = 2.04 KN/m2 -JOINTED SLAB WEIGHT = 2.16 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.102 m2 -DEPTH OF SLAB = 150 mm -NOMINAL WIDTH OF SLAB = 1200 mm -NO. OF VOIDS = 8 VOIDS -DIMENSION OF ONE VOID = AS SHOWN -PRESTRESSING STEEL YIELDING ..STRESS = 1630 KN/mm2 -REINFORCEMENT COVER = 35 mm
E C I V R E S
15
10
5
0 3
3.5
4
4.5
5
5.5
6
6.5
15.26
10.68
7.7
5.66
4.2
3.12
2.3
1.52
5 NOS 9.3mm
19.3
13.64
9.97
7.46
5.66
4.32
3.31
2.16
1.18
6 NOS 9.3mm
23.14
16.52
12.18
9.2
7.07
5.49
4.2
2.79
1.72
0.89
7 NOS 9.3 mm
23.57
19.3
14.3
10.88
8.43
6.62
4.97
3.44
2.26
1.35
0.62
8 NOS 9.3mm
24.3
20.17
15.99
12.22
9.52
7.52
5.69
4.05
2.81
1.81
1.03
0.39
9 NOS 9.3mm
24.97
20.74
17.04
13.05
10.19
8.07
6.41
4.66
3.32
2.28
1.42
0.74
SPAN (METER) 4 NOS 9.3 mm
4 NOS 9.3 mm
FOR GUIDANCE ONLY
5 NOS 9.3mm
6 NOS 9.3mm
7
7 NOS 9.3 mm
7.5
8
8 NOS 9.3mm
8.5
9
0.18
9 NOS 9.3mm
ALLOWABLE SERVICE TOTAL LOADS FOR DIFFERENT SLAB STRANDS NOS
Page 3
LOAD CHARTS AND TABLES HCS-200mm -For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications -Maximum service design load(qsls) in excess of slab weight in KN/m2
CURVES ARE CALCULATED USING BS8 110 CODE
25
20
SLAB
PROPERTIES:
-PRECAST SLAB WEIGHT = 2.47 KN/m2 -JOINTED SLAB WEIGHT = 2.63 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.12 m2 -DEPTH OF SLAB = 200 mm -NOMINAL WIDTH OF SLAB= 1200 mm -NO. OF VOIDS = 6 VOIDS -DIAMTERE OF ONE VOID = 155 mm -PRESTRESSING STEEL YIELDING ..STRESS = 1860 N/mm2 -REINFORCEME NT COVER
) 2 m / N K (
15
D A O L E C I V R E S
10
= 35 mm
5
SPAN(METER) 0
4
4.5
5
5.5
6
6.5
7
11.7
8.72
6.6
5.03
3.83
2.9
2.16
2 NOS 9.3mm + 2 NOS 12.5 mm
17.03
12.94
10.01
7.85
6.2
4.92
3.9
3.08
2.41
4 NOS 12.5mm
17.51
15.08
13.18
10.57
8.48
6.87
5.58
4.55
5 NOS 12.5mm
18.39
15.85
13.86
12.27
10.83
8.86
7.3
2 NOS 9.3mm + 5 NOS 12.5mm
19.54
16.87
14.77
13.09
11.7
10.13
7 NOS 12.5mm
19.83
17.12
15
13.29
11.89
10.71
4 NOS 9.3mm
4 NOS 9.3mm
FOR
GUIDANCE
ONLY
2 NOS 9.3mm + 2 NOS 12.5 mm
4 NOS 12.5mm
7.5
8.5
9
3.46
2.38
1.49
6.04
4.65
3.41
8.4
7.01
5.86
4.52
9.15
7.66
6.44
5.39
5 NOS 12.5mm
8
9.5
10
2.39
1.56
0.86
3.41
2.46
1.67
1
0.43
4.16
3.15
2.29
1.56
0.94
2 NOS 9.3mm + 5 NOS 12.5mm
10.5
11
7 NOS 12.5mm
ALLOWABLE SERVICE TOTAL LOADS FOR DIFFERENT SLAB STRANDS NOS
Page 4
LOAD CHARTS AND TABLES HCS-265mm -For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications CURVES ARE CALCULATED USING BS8 110
-Maximum service design load(qsls) in excess of slab weight in KN/m2
CODE
30
25
20
SLAB PROPERTIES:
-PRECAST SLAB WEIGHT = 3.61 KN/m2 -JOINTED SLAB WEIGHT = 3.82 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.176 m2 -DEPTH OF SLAB = 265 mm -NOMINAL WIDTH OF SLAB = 1200 mm -NO. OF VOIDS = 5 VOIDS -DIAMTERE OF ONE VOID = 185 mm -PRESTRESSING STEEL YIELDING ..STRESS = 1860 N/mm2 -REINFORCEMENT COVER = 35 mm
) 2 m / N K ( S D A O 15 L E C I V R E S 10
5
SPAN (METER)
0 4
4.5
5
5.5
6
6.5
7
7.5
8
4 NOS 9.3 mm
16.36
12.18
9.19
6.97
5.29
3.98
2.94
2.1
1.42
2 NOS 9.3mm + 2 NOS 12.5mm
22.34
18.18
14.05
10.99
8.67
6.86
5.42
4.26
4 NOS. 12.5 mm
23.06
19.75
17.17
14.93
11.98
9.68
7.86
6.38
6 NOS 12.5 mm
24.84
21.31
18.56
16.36
14.56
13.05
11.78
8 NOS 12.5 mm
26.55
22.81
19.9
17.56
15.65
14.06
10 NOS 12.5
27.97
24.05
21
18.55
16.55
14.89
4 NOS 9.3 mm
FOR
GUIDANCE
ONLY
8.5
9
3.31
2.53
1.87
5.18
4.18
10.53
9.24
7.78
12.71
11.55
10.55
13.47
12.26
11.21
2 NOS 9.3mm + 2 NOS 12.5mm
9.5
10
3.34
2.64
2.03
6.55
5.52
9.67
8.89
8.21
10.29
9.48
8.76
4 NOS. 12.5 mm
10.5
11
11.5
12
4.63
3.63
2.57
1.66
0.87
7.09
5.72
4.46
3.37
2.45
1.64
0.93
8.12
7.42
6.3
5.06
3.99
3.05
2.23
6 NOS 12.5 mm
12.5
8 NOS 12.5 mm
13
13.5
14
1.51
0.87
10 NOS 12.5
ALLOWABLE SERVICE TOTAL LOADS FOR DIFFERENT SLAB STRANDS NOS
Page 5
LOAD CHARTS AND TABLES HCS-320mm -For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications -Maximum service design load(qsls) in excess of slab weight in KN/m2 CURVES ARE CALCULATED USING BS8110 CODE
35
30
25
SLAB PROPERTIES:
-PRECAST SLAB WEIGHT = 3.65 KN/m2 -JOINTED SLAB WEIGHT =3.87 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.183 m2 -DEPTH OF SLAB = 320 mm -NOMINAL WIDTH OF SLAB= 1200 mm -NO. OF VOIDS =4 VOIDS -PRESTRESSING STEEL YIELDING ..STRESS = 1860 N/mm2 -REINFORCEMENT COVER = 35 mm
) 2 m / N K ( S D A O L E C I V R E S
20
15
10
5
0 5
6
7
8
9
10
5 NOS 12.5 mm
26.54
20.26
13.87
9.72
6.88
4.85
7 NOS 12.5mm
28.36
22.63
18.64
14.78
10.87
8.08
8 NOS 12.5mm
29.15
23.28
19.19
16.17
12.77
9 NOS 12.5 mm
29.87
23.87
19.69
16.61
14.24
10 NOS 12.5mm
30.53
24.41
20.15
17
14.59
11 NOS 12.5mm
31.12
24.9
20.57
17.37
14.91
SPAN (METER)
5 NOS 12.5 mm
FOR GUIDANCE ONLY
7 NOS 12.5mm
11
12
9.62
7.29
5.36
11.06
8.48
6.38
4.08
12.4
9.59
7.33
4.95
3.08
12.97
10.3
8.05
5.77
3.79
8 NOS 12.5mm
13
9 NOS 12.5 mm
14
15
2.22
10 NOS 12.5mm
ALLOWABLE SERVICE TOTAL LOADS FOR DIFFERENT SLAB STRANDS NOS
11 NOS 12.5mm
LOAD CHARTS AND TABLES HCS-400mm -For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications CURVES ARE CALCULATED USING BS8110 CODE
-Maximum service design load(qsls) in excess of slab weight in KN/m2 25
20
SLAB PROPERTIES:
-PRECAST SLAB WEIGHT = 4.15 KN/m2 -JOINTED SLAB WEIGHT =4.34 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.2074 m2 -DEPTH OF SLAB = 500 mm -NOMINAL WIDTH OF SLAB = 1200 mm -NO. OF VOIDS =4 VOIDS -PRESTRESSING STEEL YIELDING ..STRESS = 1860 N/mm2 -REINFORCEMENT COVER = 35 mm
) 2 m / N K ( S D A O L E C I V R E S
15
10
5
0 8
9
10
11
12
13
5 NOS 12.5 mm
13.02
9.35
6.72
4.78
3.3
2.15
7 NOS 12.5mm
19.72
14.64
11.01
8.32
6.28
9 NOS 12.5mm
21.37
18.36
15.05
11.66
9.08
22.4
19.27
16.78
14.46
13 NOS 12.5mm
23.28
20.04
17.48
14 NOS 12.5mm
23.67
20.39
17.79
SPAN (METER)
11 NOS 12.5 mm
5 NOS 12.5 mm
FOR GUIDANCE ONLY
14
15
4.69
3.16
1.41
7.08
5.03
3.05
1.45
11.44
9.09
6.88
4.65
2.85
15.41
12.82
10.27
8.25
6.21
4.2
2.6
1.27
15.69
13.47
10.83
8.73
6.94
4.88
3.19
1.8
7 NOS 12.5mm
9 NOS 12.5mm
16
11 NOS 12.5 mm
17
18
19
1.4
13 NOS 12.5mm
14 NOS 12.5mm
LOAD CHARTS AND TABLES HCS-500mm -For higher slab capacity concretec provide Concrete Grade 60 and different Void profiles for higher capacities -This curves is based on 1 hour fire rate and it may be change according to every project specifications -Maximum service design load(qsls) in excess of slab weight in KN/m2
CURVES ARE CALCULATED USING BS8110 CODE
35
30
25
SLAB PROPERTIES:
-PRECAST SLAB WEIGHT = 6.00 KN/m2 -JOINTED SLAB WEIGHT =6.40 KN/m2 -CONCRETE GRADE C50 -FIRE RATE REI60 -AREA OF SECTION = 0.304 m2 -DEPTH OF SLAB = 500 mm -NOMINAL WIDTH OF SLAB = 1200 mm -NO. OF VOIDS =4 VOIDS -PRESTRESSING STEEL YIELDING ..STRESS = 1860 N/mm2 -REINFORCEMENT COVER = 35 mm
) 2 m / N K ( S D A O L E C I V R E S
20
15
10
5
0 10
11
12
13
14
15
6 NOS 12.5 mm
11.42
8.44
6.18
4.41
3.01
1.89
8 NOS 12.5mm
16.93
12.99
10
7.67
5.83
22.2
17.35
13.66
10.79
8.51
13 NOS 12.5 mm
28.25
23.36
18.72
15.1
17 NOS 12.5mm
29.82
26.27
21.31
11 NOS 12.5mm
30.6
27.17
23.17
SPAN (METER)
10 NOS 12.5mm
6 NOS 12.5 mm
FOR GUIDANCE ONLY
16
17
4.33
3.11
1.92
6.68
5.17
3.71
1.91
12.23
9.92
8.02
6.34
4.23
2.5
17.32
14.16
11.63
9.52
7.78
5.76
3.86
2.27
18.91
15.53
12.8
10.57
8.72
7.16
5.2
3.47
8 NOS 12.5mm
10 NOS 12.5mm
18
13 NOS 12.5 mm
19
20
17 NOS 12.5mm
ALLOWABLE SERVICE TOTAL LOADS FOR DIFFERENT SLAB STRANDS NOS
For higher slab capacities concretec provide Concrete Grade 60 and different Void profiles for higher capacities
21
2.01
11 NOS 12.5mm
6-STRUCTURAL TOPPIN G Hollow core slab are normally used without structural topping. However, in the case of seismic action, frequent changes of load or important point loads, topping may be indicated. The thickness should be at least 50 mm, concrete quality C40. The hollow core slab and the topping will act as a composite slab and the moment capacity of the hollow core slabs can be enhanced.
FIGURE (3) SHOWING STRUCTURAL TOPPING AND REINFORCEMENT MESH 7- Diaphragm action The diaphragm action of hollow core slab is realized through a good joint design to transfer of horizontal forces to the main structure system. The peripheral reinforcement plays a determinate role not only to cop with the tensile forces of the diaphragm action but also to prevent the relative horizontal displacement of the hollow core units, so that the longitudinal joints can take up shear forces. The positioning and minimum proportioning ties, required by PCI codes, is shown in the figure below.
FIGURE (4) SHOWING DIAPHRAGM ACTION
PAGE 6
8-OPenings Opening in hollow core slabs are made as indicated in the figure. The dimensions are limit to the values given in the table. The small holes may be formed at the center of the longitudinal voids. The maximum void size is limited to the width of the void. Holes are normally made in the fresh concrete during the production process. The edges of the opening are rough. The possible dimensions for openings are given in the table. L/ B Corner (1) Front (2) Edges (3) Center (4) Square opening Round holes
HCS 150-265 600/400 600/400 1000/400 100/400 core minus 20 mm
Voids, which are wider than the width of the precast, are trimmed using transverse supports such as steel angles or concrete beams. The steel angl es can be supplied in case of client request.
FIGURE (5) SHOWING LARGE OPENING
FIGURE (6) SHOWING ALLOWABLE CUT OUT IN HOLLOW CORE SLAB
PAGE 7
9--Bearing length
The nominal bearing length of simply supported hollow core slab is give in Supporting material Slab thickness Support length (a) Nominal Minimum length effective length Concrete or steel 150mm - 265 mm 70 mm 50 mm Brick 150mm - 265 mm 100 mm 80 mm Masonry
PAGE 8
10-Connection details
CONNECTION BETWEEN HOLLOW CORE SLAB AND PRECAST WALL RESTED ON IT
CONNECTION BETWEEN CANTILIVER HOLLOW CORE SLAB AND PRECAST WALL
SECTION SHOWING REINFORCEMENT IN JOINTS
SECTION SHOWING CONNECTION BETWEEN
BETWEEN TWO ADJACENT HOLLOW CORE SLABS
HOLLOW CORE SLAB AND PRECAST BEAM
1 PAGE 9
11-Storage and transportation 11-1-Storage When storing hollow core slabs the following requirements should be taken into consideration: -Storage should only be permitted on solid ground forming a level footing. -Slab stacks are recommended to be a maximum of 3.50 – 5.00 m high depending on the slab type. Only slabs of the same length and with no large recesses should be stacked together and directly on top of each other.
FIGURE (7)
FIGURE (8)
Hollow cores storage -Wooden spacers should be used. All spacers should be stacked exactly on top of each other .see fig.( 4 , 5 ) -Special care should be given to slab with large openings. They must be stored in separate piles with only some 2-3 slabs on top of each other. The overhanging length beyond spacers should be between 200mm-400mm in normal practice and a maximum of 1000mm, when top reinforcement is used. All damage caused to slab in the stockyard should be reported to the quality control staff.
PAGE 10
-Transportation The hollow core slabs are hoisted with specially designed clamps h anging on a steel spreader beams. The use of ailing alone is strictly forbidden. Hollow core slab are transporting from our factory to the site on flat bed trailers. Full slabs are lifted using the specially designed lifting equipments (as shown).
-
flat bed trailer Used for transportation Lifting Equipments
11
-Erection
The erection of hollow core slab should be done according to the instructions of concrete.Technology’s design engineers If needed concrete technology will provide method of statements of the principles of site erection.After erection the longitudinal joints between the hollow core slab should b filled with grout,the joint should be filled carefully since they fulfill a structural function bothin the transversal load distributionand the horizontal floor diaphragm action. When a structural topping is to be used, it is advisable to fill the longitudinal point, Immediately prior to the casting of the topping.
-Fixing There are several ways of fixing hanging loads to the hollow core slabs – for example, special sockets drilled into the voids, anchors placed into the longitudinal joint or the top of the slab.
12
