kuliah 7d beton segar modulus elasticity compatibility mode

7/30/2019 Kuliah 7d Beton Segar Modulus Elasticity Compatibility Mode

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Poisson Ratio of Concrete

Ben ie Cho and Mulu o am Alemu

Undergraduate Civil Engineering

..


2/18

z Find the Modulus of Elasticity of Concretez Find Poissons Ratio of Concrete


3/18

z

Compressive Strength of Concrete Standardardized test of concrete

zAmerican Society for Testing and Materials

(ASTM)

z Correct mix

z Properly affixing strain gauges

z Properly capping the cylinder with sulfu


4/18

z

Select (5) 4in diameter by 12in lengthconcrete with 28-day age with 4 ksi design

s reng .

z

Cap all the bearing surfaces with sulfur to.

z Mark area where strain gauges will be

.z Clean area with chemical cleaners and

.


5/18

z

Affix strain gauges on their designated area,one vertical and one horizontal, using glue.

z Attach wire to strain gauges by soldering.

z Test voltage of the strain gauges.z Place and center samples on the Satec

Universal Testing Machine.

z onnec e w res o e s ra nindicator, which in turn is connected to a

.


6/18

z

Set gauge factor to 2.055 +/- .5% and zerothe strain readings.

z Begin loading the specimens and record

values of strain for given loads.z Continue testing until failure of the

specimen.


7/18

z

Compute the stress by dividing the loadby the cross-sectional area.

z Graph the strength against the vertical

and horizontal strains of each specimen.z Find values for the Youngs Modulus and

Poissons ratio from the data.

z a cu a e e eore ca va ues eYoungs Modulus and Poissons ratio.


8/18

z

Youngs Modulus E=(s1-s2)/(2-.000005)

z s1=The stress corresponding to the longitudinal

strain of 50 micro strain.2= . .

zE2=The longitudinal strain corresponding to s2.

z Poissons Ratio


9/18

= = - - = . . . .

S1= 150.63 psi 2= 962 micro strain

Cylinder #16000

si)

2000

4000

tress

(

0.4fc'

Vertical strain

0-1000 0 1000 2000 3000 4000 5000

-


10/18

Cylinder #2

6000

4000

5000

s(p

si)

Vertical strainHorizontal Strain

0.4fc'

1000

2000Stre

0-500 0 500 1000 1500 2000 2500

Strain (10E-6)


11/18

y n er

6000

3000

4000

(p

si)

Horizontal Strain

0.4 f 'c

0

1000

2000

Stres

Vertical Strain

-1000-500 0 500 1000 1500 2000 2500

Strain (10E-6)


12/18

Cylinder #45000

i)

3000

4000

s

(ps

Vertical strain

Horizontal strain

0.4fc'

1000Stre

-500 500 1500 2500 3500Strain (10E-6)


13/18

y n er

4500

5000

2500

30003500

4000

s(

psi)

Horizontal Strain

0.4 fc'

5001000

15002000

Stre ertca tran

0-1000 -500 0 500 1000 1500 2000 2500 3000

Strain (10E-6)


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Selected Values of Stress

Cylinder #1

Stress (psi) Strain (lat.) Strain (long.) Poisson's

1006.764 6 440 0.0138252004.217 -11 947 0.013640

3010.265 -20 1462 0.136800

-. .

5221.214 -222 3367 0.065930

Avg.

Poisson

Peak Stress (f 'c) Theoretical E Experimental E

0.055931 5221.214 4.1187 x 106

2.0617 x 106

Cylinder #2


2000.971 -107.8 438.3 0.245950

1007.369 -39 134.4 0.290179

3011.682 -167.9 800.8 0.1368004005.205 -191.4 1188.3 0.049460

5077.349 -8.6 1938.9 0.065930

Avg. Peak Stress (f 'c) Theoretical E Experimental E

0.1576638 5077.349 4.0615 x 106

3.36506x 106


15/18

Selected Values of Stress

Cylinder #3


1002.117 -50 303.1 0.164962011.475 -107 705.0 0.15167

3005.714 -162.5 108.6 0.14658

. - . . .

5218.121 -199.2 2196.1 0.09071

Avg.

Poisson


6 6. . . .

Cylinder #4


1002.117 -64.8 414.1 0.15648

-. . . .

3005.714 -246.1 1403.1 0.17540

4460.386 -185.9 2405.5 0.07728

Avg.Poisson


0.114836 4460.386 3.8068 x 106

2.295322 x 106


16/18

Cylinder #5


1000.207 -60.2 421.1 0.142962010.281 -116.4 825 0.14109

3003.804 -125.8 1244.6 0.10108

4616.358 -709.4 2470.3 0.28717

Avg.Poisson


0.134460 4616.358 3.8728 x 106 2.434146 x 106


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z

All specimens performed under thetheorectical values of E.

Average E= 2.60E6 psi

z Average Poisson Ratio= .119691


18/18

z

Concrete performed to designspecifications.

E= 1.5 - 5 ksi

= .1z Xiao, Yan. Experimental Analysis of Engineering Materials.

University of Southern California lecture notes 2002.

kuliah 7d beton segar modulus elasticity compatibility mode

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