CBR Test Full - Reports PDF

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FACULTY OF CIVIL ENGINEERING AND BUILTENVIRONMENTALDEPARTMENT OF CIVIL ENGINEERINGTRANSPORTATION LABORATORY (BFC32501)FULL REPORTCourse Code BFCExperiment Title CALIFORNIA BEARING RATIO (CBR) TESTDate 30/5/Section 5Group 2Members of Group 1. ZUL FADHLI BIN SUHAIMI (CF190082)2. MUHAMMAD SYAMIL BIN MO...

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FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENTAL DEPARTMENT OF CIVIL ENGINEERING TRANSPORTATION LABORATORY (BFC32501)

FULL REPORT Course Code Experiment Title Date Section Group Members of Group

BFC32501 CALIFORNIA BEARING RATIO (CBR) TEST 30/5/2021 5 2 1. ZUL FADHLI BIN SUHAIMI (CF190082) 2. MUHAMMAD SYAMIL BIN MOHD NAZRI (CF190023) 3. MUHAMMAD SYAZWAN BIN SHAMSHOL ANUAR (CF190133) 4. MUHAMMAD FUAD ADDIB POK ADI @ FUADTAYADI (CF190054) 5. MUHAMMAD HAZIM NASRULLAH BIN MOHD IDRUS (CF190109)

Lecturer/Instructor Prof. Madya Dr. MUNZILAH BINTI MD. ROHANI Element Attendance & Discipline

Aim & Purpose

1 Student submit the report 1 day late than due date Purpose is not identified; Relevant variables are not described

2 Student submit the report 12 hours late than due time Purpose is somewhat vague;

3 Student submit the report 6 hours late than due time

4 Student submit the report 2 hours late than due time

5 Student submit the report

Purpose is identified;

Purpose is identified;

early or on time Purpose is clearly identified;

Relevant variables are not described

Relevant variables are described

Relevant variables are described

Relevant variables are described

Trends/patterns are logically analysed; Questions are answered in complete

pt

wt 1

2

in somewhat unclear manner

Data Analysis

Trends/patterns are not analysed;

Trends/patterns are not analysed;

Questions are not answered; Analysis is not relevant

Answer to questions are incomplete; Analysis is inconsistent

Questions are not answered

Answer to questions are incomplete with little reflection on the lab results

Discussion

Participation

The report submitted is inorganised

The report submitted is somewhat

Trends/patterns are logically analysed

sentences;

Trends/patterns are logically analysed; Questions are answered thoroughly and in complete sentences;

Analysis is thoughtful

Analysis is insightful

Answer to questions are accurate and shows whether the results support

Answer to questions are accurate and shows whether the results support

the hypothesis

the hypothesis; Possible sources of error are identified

the hypothesis; Possible sources of error are identified and what was learned from the lab is stated clearly

The report submitted is organised

The report submitted is organised and

The report submitted is organised, structured and easy to read

for the most part; Questions are answered in complete sentences; Analysis is general Answer to questions are complete and shows whether the results support

organised NAME OF LECTURER:

structured SIGNATURE:

DATE:

TOTAL SCORE:

7

8

2

point

STUDENT CODE OF ETHIC(SCE) DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENT

I, hereby confess that I have prepared this report on my own effort. I also admit notto receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.

UL FADHLI

 Student Signature

Name : ZUL FADHLI BIN SUHAIMI Matric No. : CF190082 Date : 30/05/2021

STUDENT CODE OF ETHIC(SCE) DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENT

I, hereby confess that I have prepared this report on my own effort. I also admit notto receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.

SYAMIL

 

Student Signature

Name : MUHAMMAD SYAMIL BIN MOHD NAZRI Matric No. : CF190023 Date : 30/05/2021

STUDENT CODE OF ETHIC(SCE) DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENT

I, hereby confess that I have prepared this report on my own effort. I also admit notto receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.

SYAZWAN

 Student Signature

Name : MUHAMMAD SYAZWAN BIN SHAMSHOL ANUAR Matric No. : CF190133 Date : 23/05/2021

STUDENT CODE OF ETHIC(SCE) DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENT I, hereby confess that I have prepared this report on my own effort. I also admit notto receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.

FUAD ADDIB

 Student Signature

Name : MUHAMMAD FUAD ADDIB BIN POK ADI @ FUADTAYADI Matric No. : CF190054 Date : 30/05/2021

STUDENT CODE OF ETHIC(SCE) DEPARTMENT OF CIVIL ENGINEERING FACULTY OF CIVIL ENGINEERING AND BUILT ENVIRONMENT I, hereby confess that I have prepared this report on my own effort. I also admit notto receive or give any help during the preparation of this report and pledge that everything mentioned in the report is true.



Student Signature

Name : MUHAMMAD HAZIM NASRULLAH BIN MOHD IDRUS Matric No. : CF190109 Date : 30/03/2021

TABLE CONTENT NO

CONTENT

PAGE

1.0

INTRODUCTION

1-2

2.0

OBJECTIVE

2

3.0

APPARATUS

2

4.0

PROCEDURE

3

5.0

CALCULATION

4

6.0

RESULT AND ANALYSIS

5-12

7.0

CONCLUSION

12

8.0

REFERENCE

12

1.0 INTRODUCTION

The California Bearing Ratio (CBR) was developed by California division of highways as a method of classifying and evaluating soil-sub-grade and base course materials for flexible pavements. The CBR test is currently used in pavement design for both roads and airfield pavement. In some methods CBR is used directly and in some others it is converted to Resilient Modulus MR using the following relationships.

MR = 1500 x CBR (ibs/in2 ) MR = 10344 x CBR (Kpa)

The laboratory CBR test measures the shearing resistance of a crushed aggregate/soil under controlled moisture and density conditions. The test yields bearing ratio number that is applicable for the state of crushed aggregate/soil as tested. The CBR is obtained as the ratio of the unit stress required of effect a certain depth of penetration of the piston (1935 mm) into a compacted specimen of crushed aggregate/soil at some water content and density to the standard unit stress required to obtain the same depth of penetration on a standard sampleof crushed stone. Thus,

CBR =

Test unit stress x100 Standard unit stress

The CBR is usually base on the load ratio for the penetration of 2-5mm. If the CBR value at the penetration of 5.0 mm is larger, the test should be repeated. If a second test yields a larger value of CBR at 5.0 mm penetration then this larger value should be adopted. The CBR test are usually made on test specimens at optimum moisture content (OMC) for the crushed aggregate/soil as determined from modified compaction test.

Page 1

CBR is used to rate the performances of soils used as bases and sub grade. The followingtable gives typical rating :

CBR

GENERAL RATING

USES

0.3

Very poor

Sub-grade

3-7

Poor to fair

Sub-grade

7-20

Fair

Sub-base

20-50

Good

Base of sub-base

>50

Excellence

Base

2.0 OBJECTIVE

To determine the CBR value of the given crushed aggregate/soil sample.

3.0 APPARATUS

1. CBR equipment consisting of 152.4 mm diameter and 178 mm height, An extension collar of a diameter 51 mm, spacer disk of 150.8mm diameter and 61.4 mm height. 2. Mechanical compaction rammer 50.8 mm die, 2.49 kg and capable of free fall of 305 mm. 3. Surcharge weight to simulate the effect of overlaying pavement weight. 4. CBR machine: A compression machine, which can operate at a constant rate of 1.3mm/min. A metal piston of 1935mm2 is attached to it.

Page 2

4.0 PROCEDURE

1. CBR equipment consisting of 152.4 mm diameter and 178 mm height, An extension collar of diameter 51 mm, spacer disk of 150.8 mm diameter and 61.4 mm height. 2. Mechanical compaction rammer 50.8 mm die, 2.49 kg and capable of free fall of 305 mm. 3. Surcharge weight to simulate the effect of overlying pavement weight. 4. CBR machine: A compression machine, which can operate at a constant rate of 1.3mm/min. A metal piston of 1935mm2 is attached to it. 5. The representative crushed aggregate/soil sample is sieved through 20 mm sieve. About 5 kg of crushed aggregate/soil is taken and mixed with optimum moisture content (OMC). 6. Clamp the mould to the base plate, attach the extension collar and weight. Insert the spacer disk into the mold and place a coarse filter paper on the top of the disk. 7. Compact the aggregate /soil water mixture into the world in 3 equal layers to give a height of 127 mm compact each layer in the 10 blows, 30 blows and 65 blows for each sample. 8. Determine the water content of the crushed aggregate /soil mixture (oven for 24 hours). 9. Remove the extension collar, and using on straight edge, trim the compacted crushed aggregate/soil even with the top of the mold surface. Remove the spacer disk and weight the mold with sample. 10. Place the mold with crushed aggregate/soil on the CBR machine and place the surchargeweight at the penetration piston, set the dial gauges for load and penetration. 11. Apply the loads to the penetration piston at the rate of 1.27mm/min and record the load at 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 7.5 and 10.0 mm penetration respectively.

Page 3

5.0 CALCULATION

CBR : Plot the load deformation curve for each specimen. In some cases the initial penetration takes place without a proportional increase in the resistance to penetration and the curve may be concave upward. To obtain the true stress-strain relationships, correct the curve having concave upward shape near the origin by adjusting the location of the origin by extending the straight the portion of the stress strain curve down ward until it intersectswith x-axis.

Determine the corrected load values at 2.5 mm and 5.0 mm and determine the CBR by thefollowing relationship.

CBR =

Test unit stress x100 Standard unit stress

Standard load at 2.5 mm is taken 13.2 kN and at 5.0 mm it is on 20 kN.

Dry Density: Weight of the empty mold = A gm Weight of the mold+soil = B gm Volume of soil sample = V Weight density γ =

B−A V

Water content W 𝛾

Dry density 𝛾𝑑 = 1+𝑊 Summary of test result Sample No.

No. of Blows

1

10

2

30

3

65

𝛾𝑑 (𝑔𝑚/𝑐𝑚 3 )

CBR (%)

Page 4

6.0 RESULT AND ANALYSIS

Table 1.1: Soil properties measurement Sample

1

2

3

10

30

65

Empty weight of mould, W 1 (kg)

16.720

16.740

16.680

Weight of mould + Wet sample, W 2 (kg)

21.160

21.480

21.620

2.098 x 10-3

2.098 x 10-3

2.098 x 10-3

1

2

3

Weight of empty can, A (gm)

9.39

9.31

9.37

Weight of can + wet sample, B (gm)

53.09

70.22

45.51

Weight of can + dry sample, C (gm)

50.23

65.00

43.01

Number of blows

Volume of sample, V (m3) Can number (For moisture content)

Table 1.2: Readings Taken From CBR Loading Machine Load (kN) Penetration (mm)

Sample 1 Div.

Corrected

Sample 2 Div.

(x 0.046)

Corrected

Sample 3 Div.

(x 0.046)

Corrected (x 0.046)

0.0

0.0

0.0

0.0

0.0

0.0

0.0

1.0

6.0

0.276

9.0

0.414

0.0

0.0

1.5

9.5

0.437

9.0

0.414

9.0

0.414

2.0

9.9

0.455

9.0

0.414

10.0

0.460

2.5

9.9

0.455

9.0

0.414

10.3

0.474

3.0

16.0

0.736

11.0

0.506

13.0

0.598

3.5

24.0

1.104

21.0

0.966

17.0

0.782

4.0

32.0

1.472

35.0

1.610

45.0

2.070

4.5

45.0

2.070

54.0

2.484

85.0

3.910

5.0

59.0

2.714

76.0

3.496

115.0

5.290

5.5

74.0

3.404

103.0

4.738

163.0

7.498

6.0

87.0

4.002

132.0

6.072

213.0

9.798

6.5

103.0

4.738

162.0

7.452

264.0

12.144

7.0

109.0

5.014

195.0

8.970

304.0

13.984

Page 5

A) Weight density B) Water content

Page 6

C) Dry density D) CBR (%)

Page 7

Graph of Load (kN) vs Penetration (mm) -Sample 1

Page 8

Graph of Load (kN) vs Penetration (mm) -Sample 2

Page 9

Graph of Load (kN) vs Penetration (mm) -Sample 3

Page 10

Graph of CBR (%) vs Dry density

Summary of test result Page 11

7.0 QUESTIONS

8.0 CONCLUSION What can we summarized here is that the soil sample 1 and 2 is at good rating and suitable for the base of sub-base. While soil sample 3 gives excellent rating and should be used at base at the pavement. Generally, those sample are in good shape and good to be used as pavement . We can conclude that CBR Test is very useful to determine the performance of soil whether it is good for pavement or not.

9.0 REFERENCES



Earthworks: A Guide - Page 97 books.google.com.my N. A. Trenter · 2001



Advances in Site Investigation Practice: Proceedings of the ... - Page 91C. Craig, Institution of Civil Engineers (Great Britain) · 1996



https://en.wikipedia.org/wiki/California_bearing_ratio



https://www.iricen.gov.in/LAB/res/pdf/test-07.pdf



Geologic and Engineering Properties of Pleistocene MaterialsDon Albert Linger, Donald Thomas Davidson, Ladis H. Csanyi · 1954 · Snippet view

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