slab detailing

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aadspro SLAB DETAILING This chapter provides a step-by-step tutorial for the design, detailing, estimate and bar bending of slabs in one floor of a multi-storied building. The whole module can be sub divided into the following. 1.1 Description of the problem 1.2 Layout in AutoCAD 1.3 Steps involved in aadspro 1.4 Bar Bending Schedule 1.5 Results

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Page 1: Slab Detailing

aadspro

SLAB DETAILING This chapter provides a step-by-step tutorial for the design, detailing,

estimate and bar bending of slabs in one floor of a multi-storied building. The whole

module can be sub divided into the following.

1.1 Description of the problem

1.2 Layout in AutoCAD

1.3 Steps involved in aadspro

1.4 Bar Bending Schedule

1.5 Results

Page 2: Slab Detailing

aadspro 1.1 Description of the problem

Example 1

The structure for this problem is a double storied building; in which the first floor slab is to

be designed. Plan of the building is shown in fig.1.1.1.

Fig.1.1.1

1.2 Layout in AutoCAD

In AutoCAD A layout of the slab is provided in AutoCAD as shown in the fig 1.2.1. Here the beam

and the column position should be marked correctly, so that (span + wall thickness) of each

slab can be easily picked out.

Here wall thickness of the building is taken as 24 cm including finishes.

Page 3: Slab Detailing

aadspro

Fig.1.2.1

1.3 Steps involved in aadspro

In aadspro Select ‘Slab’ from the Main menu and ‘Slab Design’ from drop down menu.

It contains plates, ‘Slab Section Design’ (fig.1.3.1) and ‘Slab Analysis’.

In ‘Slab Section Design’ plate

Provisions are given for selecting characteristic values of concrete and steel, i.e. fck = 25 MPa

and fy = 415 MPa.

Also enter the clear cover = 30 mm and the dia of the reinforcement = 8 mm to be used.

Page 4: Slab Detailing

aadspro

Fig.1.3.1

For analysis use ‘calculate’ button against the moment and shear values. Then you will be

taken to ‘Slab Analysis’ plate, which contains three more plates viz. ‘Analysis’,

‘Design/Estimation’ and ‘Factored Load’.

In ‘Factored Load’ plate (fig.1.3.2)

modify the values of dead load, thickness of finishes, live load and factor of safety

according to which the programme calculates the total factored load, which can be

transferred to the ‘Analysis’ plate.

Page 5: Slab Detailing

aadspro

Fig.1.3.2

In ‘Analysis’ plate (fig.1.3.3)

Select Slab from the options of slab, cantilever, circular simple and circular fixed.

Select ‘Slab depth as per span’ (or ‘Slab Depth is Constant ‘as required).

Enter ‘BBS NO in dwg’ for bar bending schedule. User can enter ‘Starting bar No (BBS)’ as

per requirement. Default starting number is 1.

Enter the thickness of the slab in cm and select in the analysis plate.

Page 6: Slab Detailing

aadspro

Fig.1.3.3

A window of Automatic Slab Picking Utility (Fig.1.3.4) automatically opens up.

In ‘Automatic Slab Picking Utility ’ plate (fig.1.3.4)

Fig.1.3.4

Page 7: Slab Detailing

aadspro

Select ‘slab’ and input unit.

Select for picking slabs from AutoCAD.

In AutoCAD, select all the slabs using a cross window. The slab points picked will be

updated into a table within this utility. Double click or press F9 on the Slab name to edit

the coordinates

In AutoCAD, the selected slabs would be marked by the respective Slab name and a

temporarily line (Fig.1.3.5) spanning across the slab inner dimensions. These can be erased

by using in the above plate.

option allows the user to manually select any missed out slabs.

From the table, to delete any slab detail, select the Slab name and Ctrl + Delete.

Data from the table can be exported to or imported from excel file using and

respectively.

Close option closes this utility.

Fig 1.3.5

Enter for transferring all the co-ordinate points to Slab Design System

plate.

In ‘Slab Design System’ plate

Page 8: Slab Detailing

aadspro

‘Slab Design System’ plate is divided into three more plates viz., Final details, Moments

and Modify slab.

In Modify Slab ((fig.1.3.6)

Enter ‘Wall thickness’ = 24 cms.

An option is present for ‘Auto Depth’, which provides depth for the selected slab depending on

the shorter span (i.e. Lx) as shown in the fig.1.3.7.User can modify this table.

Fig .1.3.7

In ‘Effective Depth’, we can edit the Depth, Load & dia of bar as per requirement.

In ‘Effective Depth’, the volume of individual slabs are shown.(beams are excluded) fig.1.3.8

‘Total Volume’ of all the slabs are added up and shown at the bottom of the slab

Fig .1.3.8

Page 9: Slab Detailing

aadspro

Fig.1.3.6

Minimum spacing of reinforcement at discontinuous supports.

coefficient of top bar at discontinuous support.

coefficient of top bar at continuous support.

for splitting the top and bottom reinforcement.

Enter for detailing to start in the AutoCAD.

The AutoCAD command which appears after selecting ‘Start Detailing’ is

Slab detailing starts after picking the bottom left points of two slabs.

Moments and reinforcement details will be calculated in the software.

Page 10: Slab Detailing

aadspro In Moments (fig .1.3.9)

Corresponding to each slab, which is represented by a slab number as shown in

AutoCAD, the moments at the midspan and support both in X and Y direction is

shown.

Extra moments in X and Y direction, if present, is also shown.

Fig .1.3.9

In Final Details (fig .1.3.10)

Corresponding to each slab numbers, the short span (Lx) and long span(Ly), the main

bars and the corresponding spacing in X and Y direction is obtained.

Extra bars in both the directions can also be obtained in this plate.

Page 11: Slab Detailing

aadspro

Fig .1.3.10

In ‘Slab Reinforcement’ plate(fig.1.3.11)

In ‘Straight Slab Info’, the reinforcement details are automatically transferred from ‘Slab

Design System’ plate.

Page 12: Slab Detailing

aadspro

Fig .1.3.11

Here, L (H) - Length of bar in Horizontal direction on the Left side of slab.

M (H) - Length of bar in Horizontal direction on the Middle of slab.

R (H) - Length of bar in Horizontal direction on the Right side of slab.

B (V) - Length of bar in Vertical direction on the Bottom of slab.

M (V) - Length of bar in Vertical direction on the Middle of slab.

T (V) - Length of bar in Vertical direction on the Top of slab.

HSpc - Size of bar in Horizontal direction of slab.

VSpc - Size of bar in Vertical direction of slab.

LHNos, MHNos, RHNos - Number of bars in Horizontal direction.

BVNos, MVNos, TVNos - Number of bars in Vertical direction.

S. Len - Length of Slab.

S. Wid - Width of Slab

The various columns in the table above (fig.1.3.11) are explained in the fig below. (Fig .1.3.12).

Page 13: Slab Detailing

aadspro

Fig 1.3.12

Note:

Reinforcement at continuous support won’t be divided into two, but will be taken as a single

member for a slab. The same member for the adjacent slab will be taken as zero.

converts these values to ‘Slab-BBS’ plate.

1.4 BAR BENDING SCHEDULE

Page 14: Slab Detailing

aadspro

In ‘Slab -BBS’ plate, (fig .1.4.1)

Fig .1.4.1

‘Slab BBS’ gives the bar bending schedule for the problem.

button, fills the Tot: Bars and Len (Bar) mm columns in the table.

An option is also provided to import from Excel.

Here,

• Brmk = Bark mark

• Type = Type of reinforcement

• Size = Bar diameter size

• Mem No = Number of repetitions of the member.

• Bar No/Mem = Number of bars of same length and dia.

• Total Bars = Mem No x Bar No/ Mem

• Len(Bar)mm = Length of bar in mm

• ShpCode = Shape code (Each shape is represented by a number)

• A, B etc = Representations in shape code. (For details, refer ‘Full floor beam

design’)

‘Save Excel’ option saves the schedule to Excel.

Enter . For details, refer ‘Full floor beam design’.

1.5 RESULTS

The slab reinforcement detailing automatically starts in AutoCAD.

Page 15: Slab Detailing

aadspro

The length of each bar, bar diameter and corresponding spacing is obtained.

Here D =110 represents depth of the slab.

34, 37 etc represents bar number for Bar bending schedule.

Here both the Bottom and Top reinforcement are shown together.

Fig.1.5.1 shows Bottom reinforcement of the slabs.

Fig.1.5.1

Fig.1.5.2 shows Top reinforcement of the slabs.

Page 16: Slab Detailing

aadspro

Fig.1.5.2