1. WELL COME TO PRESENTATION FOR CONCRETE COMPRESSIVES TEST USING CYLINDER
PRESENTED BY
FARJANA SHAKE
NOWSHIN FARHANA MITU
MUKTA KHANOM
FATEMA AKTHER
JANNATUL NAIM TANNI
SHEJUTHE SARKAR KOTHA MONI
FARHANA AKTHER NISHI
SARMIN AKTHER
KHANDOKAR MAHAMUDA TULI
FALGUNI AKTHER
SHANTA ISLAM

2. WHAT COMPRESSIVE STRENGTH OF CONCRETE
Compressive strength is the maximum compressive stress that, under a gradually applied load, a given solid material can sustain without fracture. Compressive strength is calculated by dividing the maximum load by the original cross-sectional area of a specimen in a compression test.

3. WHY TO COMPRESSIVE STRENGTH OF CONCRETE
To determine load bearing capacity of concrete
For designers, compressive strength is one of the most important for engineering roperties of concrete.

4. USING APPARATUS OF COMPRESSIVE TEST
Compression testing machine
Cylinder mold of 150mm diameter and 300mm height
Weighing balance. ,

5. Procedure of Concrete Compression Test
Step1 – Preparation: Check all the things to need are
ready. Check concrete compression machine is in
working order.
Step2 – Safety:
Wear hand gloves
and safety goggles.

6. Procedure of Concrete Compression Test
Step3 – Taking measurement: Take the measurement of concrete specimens (which are sent to laboratory for testing). Calculate the cross sectional area (unit should be on mm2) and put down on paper. Do the same for each specimen.
Step4 – Start machine: Turn on the machine. Place one concrete specimen in the centre of loading area.

7. Procedure of Concrete Compression Test
Step5 – Lowering piston: Lower the piston against the top of concrete specimen by pushing the lever. Don’t apply load just now. Just place the piston on top of concrete specimen so that it’s touching that.

8. Procedure of Concrete Compression Test
Step6 – Applying load: Now the piston is on top of specimen. It is the time to apply load. Pull the lever into holding position. Start the compression test by Pressing the zero button on the display board.

9. Procedure of Concrete Compression Test
Step7 – Increasing pressure: By turning pressure increasing valve counter-clockwise, adjust the pressure on piston so that it matches concrete compression strength value. Apply the load gradually without shock.
Step8 – Test is complete: Observe the concrete specimen. When it begins to break stop applying load.

10. Procedure of Concrete Compression Test
Step9 – recording: Record the ultimate load on paper displaying on machine’s display screen.

11. Procedure of Concrete Compression Test
Step10 – Clean the machine: When the piston is back into its position, clean the creaked concrete from the machine.

12. Procedure of Concrete Compression Test
Step11 – Turning off machine: Match your record once again with the result on display screen. The result should still be on display screen. And then turn off the machine.

13. Procedure of Concrete Compression Test
Step12 – Calculate concrete compressive strength: The result we got from testing machine is the ultimate load to break the concrete specimen. The load unit is generally in KN( newton). Our purpose is, to know the concrete compressive strength.
Data:
Sample – 1 = 245 KN
Sample – 2 = 265 KN
Sample -3 = 255 KN

14. Procedure of Concrete Compression Test
We know, compressive strength is equal to ultimate load divided by cross sectional area of concrete specimen. We took the concrete specimen’s measurement before starting the testing and calculated cross sectional area.
Average Load =255KN = N
PerUnit Load = / =14.43 /Nsq-mm
= psi

15. Procedure of Concrete Compression Test
Now we got the ultimate load. So we can now calculate the concrete compressive strength.   Compressive strength = Ultimate load (N) / cross sectional area (mm2). The unit of compressive strength will be N/mm2.
Normally 3 sample of concrete specimens are tested and average result is taken into consideration. If any of the specimen compressive strength result varies by more than 15% of average result, that result is rejected.

16. THANKS
ALL OF MY
HONORABLE TEACHER AND
FRIENDS