CBR Test - lab report data(bearing ratio) PDF

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TITLE OFEXPERIMENT: CBR TESTDATE OFEXPERIMENT: 17/11/GROUP :GROUP MEMBERS : 1. WAN NUR AMIRAH FARHANA BINTI RAZALI(2018420518)2. MUHAMMAD ADLI AMIN BIN MOHD AMZUKI(2018677652)3. MUHAMMAD NAQIB IRFAN BIN NAZARUDDIN(2018282842)4. MOHD AIDIL IRFAN BIN ROSLI (2018431952)LECTURER : EN. MUHAMMAD MOHKTAR B...

Description

HIGHWAY ENGINEERING ECG344 OPEN-ENDED LAB OCTOBER 2020 – JANUARY 2021 TITLE OF EXPERIMENT DATE OF EXPERIMENT GROUP GROUP MEMBERS

LECTURER LEVEL OF OPENESS NO

: CBR TEST : 17/11/2020 : : 1. WAN NUR AMIRAH FARHANA BINTI RAZALI (2018420518) 2. MUHAMMAD ADLI AMIN BIN MOHD AMZUKI (2018677652) 3. MUHAMMAD NAQIB IRFAN BIN NAZARUDDIN (2018282842) 4. MOHD AIDIL IRFAN BIN ROSLI (2018431952) : EN. MUHAMMAD MOHKTAR BIN SAMAT :0

ELEMENT

COPO

COMMENTS

Marks

1

INTRODUCTION

2

BASIC CONCEPT

3

SUMMARY OF PROCEDURES/METHOD

4

ANALYSIS AND INTERPETATION OF DATA

5

DISCUSSION OF RESULT

2

4

6

8

10

6

CONCLUSIONS

2

4

6

8

10

TOTAL MARKS

/20

DATA Type of Compaction: Dynamic Maximum Dry Density, MDD = 2.060 g/cc Optimum Moisture Content, OMC = 7.30% Soaking period = 96 hours Surcharge weight = 5.0 kg Weight of original sample = 6.8 kg Description No of blows Mould no. Volume of mould, v (cc) Weight of mould (g) Weight of mould + compacted soil (g) Weight of compacted soil (g) Wet density of soil (g/cc) Container no. Weight of container (g) Weight of container + wet soil (g) Weight of container + oven dry soil (g) Weight of water (g) Oven dry soil (g) Water content (%) Dry density of soil % of MDD

10 07 2250

Before soaking 30 65 08 09 2250 2250

10 07 2250

After soaking 30 08 2250

65 09 2250

6455 10790

6480 10350

6825 11890

6455 10995

6480 11440

6825 11865

4335

4870

5065

4540

4960

5040

1.927

2.164

2.251

2.018

2.204

2.240

A-1 60.21

Water content data A-2 A-3 60.88 60.73

A-19 61.17

A-20 63.00

A-21 60.83

337.18

300.43

317.60

359.84

270.61

215.38

318.16

284.13

299.69

329.55

253.08

203.03

19.02 257.95 7.37 1.794 87.09

16.30 223.25 7.30 2.017 97.91

17.91 238.96 7.49 2.094 101.65

30.29 268.38 11.29 1.813 88.01

17.53 190.08 9.22 2.018 97.96

12.35 142.20 8.68 2.061 100.05

89iProving ring constant = 5.876 kg/Div Penetration rate = 1.25 mm/min 10 30 65 No of blows Mould no. Mould no. Mould no. Mould no. Penetration Proving Load Corrected Proving Load Corrected Proving Load Corrected (mm) ring in (kg) load (kg) ring in (kg) load (kg) ring in (kg) load (kg) reading reading reading (Div) (Div) (Div) 0.00 0.50 16 94.02 14 82.26 15 88.14 1.00 24 141.02 28 164.53 37 217.41 1.50 26 152.72 37 217.41 54 317.30 2.00 30 176.28 45 264.42 66 387.82 2.50 33 193.91 51 299.61 74 434.82 3.00 35 205.66 56 329.06 84 493.58 4.00 38 223.29 63 370.19 100 587.60 5.00 41 240.92 70 411.32 117 687.49 7.50 56 329.06 83 487.71 128 752.13 10.00 73 428.95 92 540.59 144 846.14 12.50 85 499.46 103 605.23 154 904.40 CBR of specimen 14.08 21.90 31.75 at 2.5 mm CBR of specimen 13.38 21.90 33.33 at 5.0 mm CBR value 20.70% of sample

PercentageMDDvsCBRGraph 105 100

CBR

95 90 85 80 75 14.08

21.9

33.33

%MDD %MDD

At 97% MDD, the CBR is 20.70%

DISCUSSION The California Bearing Ratio (CBR) is a test that conducted in construction materials laboratories to determine the strength of soil subgrades and base course materials. The engineer will use this test to design airport runways and taxiways, parking lot and other pavements. The California Bearing Ratio (CBR) field test represent in-situ strengths of the material under existing material. Usually, the data of this test will not correlate with California Bearing Ratio (CBR) laboratory by using the same material. Saturation levels are near 100% for soaked laboratory samples. Field materials are often less than 80% saturated. Therefore, it is more resistant to penetration. Typical California Bearing Ratio Values Table

Unified Soil Classification System Soil Class

Soil Type

Laboratory California Bearing Ratio Range

Field California Bearing Ratio Range

GW

Well Graded Sandy Gravel

20 – 60

60 – 80

SW

Well Graded Sand

15 – 40

20 – 40

SC

Sandy Clay

4–7

10 – 20

CL

Clay

1–3

5 – 15

CONCLUSION

California bearing ratio test is one of the most widely used methods to determine the strength of a sub grade soil, sub foundation, and base course material for construction of thickness for highways and airfield pavement. The CBR test is penetration test aimed to evaluate subgrade strength of roads and pavements. With empirical curves, the results obtained by these experiments are used to determine the thickness of the pavement and its component layers. For the design of flexible pavement, this is the most common method. REFERENCE 

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