e3 guide rc project nagy-gyorgy t 2014 v2

8/12/2019 E3 Guide RC Project Nagy-Gyorgy T 2014 v2

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REINFORCED CONCRETE DESIGN GUIDE

1ST PART

Prepared byNAGYGYRGY TamsPhD, Lecturer

tamas.nagy [email protected]

FLORU CodruPhD, Assistant Lecturer [email protected]

2014 V2


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REFERENCES

SR EN 1992-1-1: 2004, Proiectarea structurilor de beton, Partea 1-1: Reguli generale pentru cl diri(+AC:2008)

SR EN 1992-1-1/NB: 2008, Proiectarea structurilor de beton, Partea 1-1: Reguli generale pentru cl diri. Anexa Na ional

EN 1992-1-1: 2004, Design of concrete structures - Part 1-1: General rules and rules for buildings

SR EN 1991-1-1:2004, Ac iuni asupra structurilor. Partea 1-1: Ac iuni generale (+ NA:2006)

P 100-1/20013, Cod de proiectare seismic - Partea I - Prevederi de proiectare pentru cl diri

Cadar I., Clipii T., Tudor A., Beton Armat (ed. II), Ed. Orizonturi Universitare, 2004, ISBN 973-638-176-5

Kiss Z., One T., Proiectarea structurilor de beton armat dup SR EN 1992-1, Ed. Abel, 2008, ISBN973114070-0

Mosley W.H., Burgey J.H., Hulse R., Reinforced Concrete Design to Eurocode 2, Sixth Edition, 2007, ISBN:9780230500716

Nilson A., Darwin D., Dolan Ch., Design of Concrete Structures (13th Ed.), McGraw-Hill Co, 2004, ISBN 0-07-248305-9

Newman J., Choo B. S., Advanced Concrete Technology SET, Ed. Elsevier Science, 2003, ISBN-13:9780750656863


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I. DESIGN OF A RC CASTINPLACE SLAB

1. ELEMENTS OF A FLOOR

- STRUCTURAL ELEMENTS , WITH STRENGTH ROLE

- SLAB AND BEAMS (DISPOSED IN ONE OR TWO DIRECTIONS, WHICH SUPPORTS THESLAB)

- NON-STRUCTURAL ELEMENTS , E.G. PROTECTIONS- FINISHING, FLOORS, ISOLATIONS (ACOUSTIC, HYDRO-), INSULATIONS

GIRDERS (MAIN BEAMS) BEING ALSO IN THE SAME TIME BEAMS OF THE FRAME

SECONDARY BEAMS DISPOSED PERPENDICULAR TO THE GIRDERS, BEINGEQUIDISTANT (AS IS MUCH AS IT IS POSSIBLE), THE DISTANCEBETWEEN THEIR AXIS BEING

IN THE CASE OF SLABS REINFORCED IN ONE DIRECTION, THE RATIO

OF A SLAB PANEL RESPECTS THE CONDITION:


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The cast-in-place floor is a space structure, because, through concrete andsteel reinforcement a link between the component elements is created.

The computation of a space structure is quite difficult , therefore, in design isaccepted the calculation of each structural element separately , taking intoaccount the load transmission modes, in vertical direction, toward the supports .

In this way, it could be admitted that the slab ( S ) is supported by the secondarybeams ( SB ), the secondary beams are supported by the girders ( G) and columns(C) and the girders together with columns are forming the frame, which transmitsthe loads to the foundations ( F) and to the terrain.

S SB frame = G + C F terrain

The route of the loads specifies the order in which the design of the structural element must be done, i.e.design of the slab, then secondary beams, girders, etc.


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n x B

L

L

GirdersSecondary beams

Slab panel

Columns

Detail A

(bay)

( s p a n

)

Transversal sectionsgirder secondary beam

secondary beam

girder

Girder secondary beam

Detail A


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Formwork plane


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Formwork plane


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Formwork plane


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Formwork plane


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Formwork plane


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Formwork plane


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Formwork plane


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Formwork plane


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DESIGN PHASES

- PRE-DIMENSIONING : choosing the structural elements dimensionsaccording to the recommendations, in such a way to correspond also to other criteria that the strength;

- COMPUTATION OF THE LOADS : determination of the design loads,knowing the structural elements dimensions, the composition of non-structuralelements, destination and location of the construction;

- ESTABLISHING THE STATIC SCHEME FOR DESIGN based on the design

spans of the elements;

- STATIC DESIGN : determining the most unfavourable effects of design loadswhich acting on the admitted static scheme. It can be solved by using CADprograms or manually, with approximate methods;


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DESIGN PHASES (contd)

- THE PROPER DESIGN , through following steps:

- finalization of the elements cross section , based on the resultsfrom the static calculations and on the used material characteristics;

- computation of the reinforcement area and setting their layout ;

- execution drawing , which includes the framework plane and

reinforcement layout, reinforcement details and material consumptions(volume of the concrete and reinforcement).


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2. PRE-DIMENSIONING THE ELEMENTS OF THE FLOOR

SLAB

IF YES SLAB REINFORCED IN A SINGLE DIRECTION

(Conf. P100-1/2013)

hs = M x 10 mml = interaxis

Section aah s


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BEAMS

bmin = 200 mmh, b = M x 50 mmL = interaxis

DIMENSION RECOMMENDATIONS

HEIGHT

Minimum, hminL/(1215) girders

L/20 secondary beams

Optimum, hopt L/(812) girders

L/(1215) secondary beams

WIDTH h/b = 1.5 3 rectangular section


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COLUMNS (is chosen)

bCOL = (bG + 5cm) 350 mm

hCOL 1,2 b COL

h, b = M x 50 mm


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3. COMPUTATION OF LOADS

ACTION CHARACTERISTICS EXAMPLES

PERMANENT Variation in time is

negligibleSelf weight: structural elements,finishing, etc.

VARIABLE Variation in time is

important

Loads resulted from using of the buildings (live loads)

WindSnow

ACCIDENTAL High intensity, reduced time of actionEarthquake Explosion

Design value of action

Partial safety coefficient

Characteristic value of action


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GENERALLY, THESE LOADS CAN BE CONSIDERED UNIFORMLYDISTRIBUTED ON THE SLAB SURFACE AND THERE ARE EXPRESSED INkN/m 2.

FOR THE CHARACTERISTIC VALUES k

DESIGN VALUES d


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PERMANENT (DEAD) CHARACTERISTIC LOADS : gk

SELFWEIGHT

- RC SLAB

- PLASTER

- FLOOR

- Asphalt

- Mosaic

- Pavement

- Cement concrete lining

P

, , , 2 , 2

, 2

, 2

,


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MATERIALS SPECIFIC WEIGHT

[kN/m3]

CONCRETES

R. C. 25.0

FINISHING PLASTERS

Cement mortar 21.0

Cement lime mortar 19.0

Lime or plaster mortar 17.0


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VARIABLE (LIVE) CHARACTERISTIC LOADS : qk

IMPOSED LOADS

- CATEGORIES OF USE

- PARTITION WALLS

(according to SR EN 1991-1-1:2004)

Q

,,

,


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PERMANENT DESIGN LOADS

VARIABLE DESIGN LOADS

TYPE OF LOAD

PARTIAL SAFETY FACTOR FOR ACTIONS

F

PERMANENT LOADS g = 1.35

VARIABLE LOADS q = 1.50


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4. STATIC DESIGN OF THE SLAB

ESTABLISHING THE STATIC SCHEME

-The real slab is replaced with a continues beam having spans of l c and linear

distributed loads of pd x 1 m [kN/m]

Envelope curves

gd,gs/q d,gs = 0,5

gd,gs /q d,gs = 5


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4. STATIC DESIGN OF THE SLAB


-The real slab is replaced with a continues beam having spans of l c and linear

distributed loads of pd x 1 m [kN/m]

14

envelope curves


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5. DIMENSIONING OF THE SLAB

CHARACTERISTIC AND DESIGN STRENGTH

CONCRETE

Quality of concrete is defined by the strength class, which is the characteristic

compressive strength on cylinders

Concrete class is

Design compressive strength of concrete

REINFORCEMENT

Design strength of reinforcement

,


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CHARACTERISTIC AND DESIGN STRENGTH


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FINALIZING THE THICKNESS OF THE SLAB

Design section of the slab

Reinforcement of the slab popt (%) for reinforcing with f yk = 400 500 N/mm 2 f yk = 300 400 N/mm 2

In 1 direction 0,25 0,50 0,30 0,60

In 2 directions 0,20 0,50 0,25 0,50

s s

hs


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Checking of the chosen thickness (necessary)

MEd the maximum bending moment from the static designb = 1000 mm

or = f( ) table , where

, in function of popt

100 1 0.5


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Computation of the necessary slab thickness

where,

/2


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Computation of the necessary slab thickness

!!!!!!!!! in function of the Exposure Classand Structural class ( Ch. 4.4 )

h s = M x 10 mm

max ,; ,;10

,

0.1 2

bond

durability

5 , 10 25


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If

OK

If

RE-CALCULATION OF THE LOADS MOMENTS

FINALIZING THE SLAB THICKNESS

,

,

, ,


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CALCULATION OF THE REINFORCEMENT AREA

Effective depth:

2


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DETAILING RULES principal reinforcements(SR EN 1992-1-1/ Ch. 9)

straight (bound) bars

welded bars (welded fabrics)

, 0.26 0.0013

, 0.04

1.5 200 . . 80 0.1 2 6

5

ngyt1

l d


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Slide 37

ngyt1 in conformity with the N.A.tamas.nagygyorgy, 11/03/02


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DETAILING RULES principal reinforcements(SR EN 1992-1-1/ Ch. 9)

- At the edge of the slab

- Perpendicular to the girder , 25%, , 6/ l o

G P gs

gsgs

gs

lo /4


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DETAILING RULES secondary reinforcements(SR EN 1992-1-1/ Ch. 9)

= min 20% A s

2.5 300 . .ngyt2

Slide 39


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Slide 39

ngyt2 in conformity with the N.A.tamas.nagygyorgy, 11/03/02


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DETAILING RULES welded wire mesh (fabric) reinforcements(SR EN 1992-1-1/ Ch. 9)

- At the edge of the slab

- Perpendicular to the girder , 50, , , 5 l o

G P gs

gsgs

gs

lo /4


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5.58cm 2

4.52cm2

3.50cm2

3.50cm2


5. DIMENSIONING OF THE SLABSLAB LAYOUT reinforcement with inclined bars

I DESIGNOFARCCASTIN PLACESLAB


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5.58cm 2

4.52cm2

3.50cm2

3.50cm2


5. DIMENSIONING OF THE SLABSLAB LAYOUT reinforcement with inclined bars



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5.58cm2

4.52cm2

3.50cm2

3.50cm2


5. DIMENSIONING OF THE SLABSLAB LAYOUT reinforcement with straight bars



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5. DIMENSIONING OF THE SLABSLAB LAYOUT reinforcement with welded wire mesh (welded fabric)



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CHECKING THE SLAB FOR SHEAR FORCES

Generally , in the case of usual slabs with low thickness, the reinforcement isresulting from the design for bending and reinforcement for shear force is notneeded.

To verify this:

, , , 100 1/3 0.035 3/2 1/2

, 0.18/

1200 2.00

0.02

II DESIGNOFTHESECONDARYBEAM


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II. DESIGN OF THE SECONDARY BEAM


B

l o sbbG bG

bsb

G

s.b

s.b

s.b.

G



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P , , Q , ,

bsb

, ,

B

l o sbbG bG

G

s.b

s.b

s.b.

G

IT IS THE TOTALLOAD!!!



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2. STATIC DESIGN OF THE SECONDARY BEAM


The secondary beam will be computed as a continues beam, with designspans , the supports being the girders. 0,

11

II.DESIGNOFTHESECONDARYBEAM


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3. DIMENSIONING OF THE SECONDARY BEAM

As1 Step 1

As1 Step 2

As1 Step 1

As2 = the minimum betweenthe reinforcements obtainedfrom the adjacent spans inStep 1 (here from M 1 and M2)

As1 Step 2



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FINALIZING THE HEIGHT OF THE SECONDARY BEAM

Checking the chosen height (necessary)

M Ed - maximum bending moment from the static design

bsb - from pre-dimensioningor = f( ) table, where

, in function of popt 1.2 1.8

100 1 0.5



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Computation of the necessary height

,

long stirr

cnomC nom,longd s /2

max ,; , 10



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Computation of the necessary height

!!!!!!!!!!!!!!!!!!in function of the Exposure Classand Structural class ( Ch. 4.4 )

h sb = M x 50 mm and then verification h sb /b sb =1,5 3,0 ???

max ,; ,;10

,

20 25

bond

durability

10 , 10 25



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If

OK

If

RE-CALCULATION OF THE LOADS MOMENTS


, ,

, ,



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DESIGN OF THE REINFORCEMENTS IN SPAN simple reinforced T section

The effective width of the flange ( beff ), depends on the web and flangedimensions, the type of loading, the span, the support conditions and thetransverse reinforcement.

The effective width of the flange ( beff ) should be based on the distance l 0between points of zero moment.

(B) (B) (B)



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, , 0,2 0,10 0,20,

beff



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Table method

If > lim re-dimensioning of the section

/

/

2


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DETAILING RULES(SR EN 1992-1-1/ Ch. 9 and P100/1-2006, Ch.5)- At the edge of the beam

- Anchorage of bottom reinforcement at end support

- Anchorage at intermediate supports

, 15%,



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DETAILING RULES

>0.3l o >0.3l o >0.3l o

~10cm

l

10d

l bd

l bd

min 2

min 228 secondary

min 2

min 2

A B A

28 secondary



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DETAILING RULES

(ch. 8.4.4)

for anchorages in tension

for anchorages in compression, 0.3,;10;100

, 0.6,;10;100

12345 , ,, /4/

4


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DESIGN OF THE REINFORCEMENTS ON THE SUPPORTSdouble reinforced rectangular cross section

Is calculated

- If a > lim re-dimensioning of the section

- If a < 0

2 22

1 2

IT IS THE MINIMUMEFFECTIVE AREA !!!


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DESIGN OF THE REINFORCEMENTS ON THE SUPPORTSdouble reinforced rectangular cross section

Is calculated

- Must be checked if no yielding of compressed reinf.F c acts at the level of F s2

2 22

IT IS THE MINIMUMEFFECTIVE AREA !!!

1.25 1 1 2

2 /

2 2



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DESIGN FOR SHEAR FORCEComputation the shear resistance of concrete

, 0.18/ 1 200 2.00

0.02

, , 100 1/3 0.035 3/2 1/2



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DESIGN FOR SHEAR FORCE

If minimum shear reinforcement will be provide

For providing of double-arm stirrups

,

, 0.08

, 0.75 1 400



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DESIGN FOR SHEAR FORCE

If is imposed = 45 o (crack)

= 90 o (stirrups)where z 0,9d

choose Asw = n x sw snec

and then must be verified if

,



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DESIGN FOR SHEAR FORCEDETAILING RULES

To have a ductile failure

Where

, , 0.51

1 0.6 1 250


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e3 guide rc project nagy-gyorgy t 2014 v2

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