FACULTY OF CIVIL & ENVIRONMENTAL

ENGINEERING

DEPARTMENT OF GEOTECHNICAL &

TRANSPORTATION ENGINEERING

ENGINEERING GEOLOGY & GEOPHYSIC LABORATORY

REPORT SUBJECT CODE BFC 21303

TEST CODE & TITLE SLAKE DURABILITY TEST

COURSE CODE BFF

TESTING DATE 22 MARCH 2011

STUDENT NAME MUHAMMAD RIDHWAN BIN KAMARUDIN

(DF100038)

SECTION/GROUP SECTION 1

GROUP MEMBER NAMES 1. MUHAMMAD IKHWAN BIN ZAINUDDIN

(DF100018)

2.MUHAMMAD ZAMIR BIN SAMEON (DF100065)

3.MUKHLIS BIN ADAM (DF100080)

4. MUHAMMAD NUH BIN AHMAD ZAIRI (DF100093)

5. HANISAH BINTI HAMZAH (DF100052)

LECTURER/ INSTRUCTOR/

TUTOR NAME

IR. AGUS BIN SULAEMAN

REPORT RECEIVED DATE 15 APRIL 2011

MARKS ATTENDANCE,

DISCIPLINE &

INVOLVEMENT

/15%

DATA ANALYSES /20%

RESULT /20%

DISCUSSION /25%

CONCLUSION /20%

TOTAL /100%

EXAMINER COMMENT

RECEIVED STAMP

SLAKE DURABILITY TEST

1.0 OBJECTIVE

A test to estimate the resistance of rocks, particularly argillaceous rocks, to a

combination of wetting and abrasion. Test results are expressed as a slake durability

index for each particular rock. The slake-durability test is regarded as a simple test for

assessing the influence of weathering on rock

1.1 LEARNING OUTCOMES

i. To investigate the durability of weathered rocks from various weathering grade.

ii. To determine the limit of weathering grade for the rocks to be tested by using the

standard durability test.

1.2 THEORY

The slake-durability test is regarded as a simple test for assessing the influence of

weathering on Rock and its disintegration. However, mechanisms involved in this

slaking test have not been fully understood yet even after so many years. The

mechanisms movements of the rocks inside the apparatus are understood but its

effect on weathering is still unknown. Franklin and Chandra indicated that

mechanisms in slake-durability tests are subjected to ion exchange and capillary

tension. For rocks containing clay materials, the exchange of cations and anions take

place with the adsorption and absorption of water which makes the rock swell in size

and slaking occurs.

With the duration of the test of only ten minutes, the wetting process may only take for

parts of the rock, particularly for the surface part but due to appropriate rotation speed

and the level of the water most of the parts of the rocks get wet.

When the rock becomes more saturated, water menisci within the rock pores

increase, which then causes the reduction of capillary tension at grain contacts and

the tips of cracks. Due to the increase in the water content in the pores, fracture

develops in the rock which leads to the weathering of rocks. This mechanism seems

to dominate the durability behavior of porous rock.

Water certainly influences the mechanical characteristics of rock. However, in the

slake durability test, not only wet-dry conditions are given to the rock specimen, but

also mechanisms correspond to the drum rotation are involved. These mechanisms

have not been explored. Such mechanisms may be influenced by the shape and

weight of the specimen. Therefore the main objective of the study is to determine the

slake durability index of the rock samples rather than analyzing the mechanisms of

the specimen.

1.4 PROCEDURE

The slake-durability test was intended to assess the resistance offered by a rock sample to weakening and disintegration when subjected to two standard cycles of drying and wetting.

i. Rock samples were put into an apparatus that comprises two sets of drums of the length of 100 mm and the diameter of 140 mm.

ii. The two drums rotated in water that had a level of about 20 mm below the drum axis.

iii. The rotation was driven by a motor capable of rotating the drums at a speed of 20 rpm, which was held constant for a period of 10 minutes.

iv. Ten rock lumps, each had a mass of 40-60 g, were placed in the drums.

v. After slaking for the period of 10 minutes, these rock samples were then dried in

an oven at a temperature of 105 degree centigrade for up to 6 hrs.

vi. Finally, the mass of dried samples was weighted to obtain the first cycle. The test was conducted over two cycles, in which the weight of particles of 10 rock lumps retained in these wet-dry cycling tests was therefore determined.

1.5 RESULT AND ANALYSIS

Method Of Calculation i. Initial weight taken = A ii. Weight after 1st cycle = B iii. Weight after 2nd cycle = C iv. Drum = D v. % retention after 1st cycle =(A-B)/A x 100 vi. % retention after 2nd cycle=(B-C)/B x 100

DATA

Weight (Before):

Weight (After put in oven)

First Cycle:

Second Cycle:

Weight Drum :

CALCULATION

Initial Weight (A)

Sampel (A) Berat (g)

Air Hitam 529.3

Minyak Beku 500.6

SAMPLE

Batu Air

Hitam (g)

Batu Minyak

Beku (g)

529.3 500.6

SAMPLE

Batu Air

Hitam (g)

Batu Minyak

Beku (g)

529.3 500.6

SAMPLE A

Batu Air

Hitam (g)

Batu Minyak

Beku (g)

528.9 498.2

SAMPLE A

Batu Air Hitam

(g)

Batu Minyak

Beku (g)

526.4 496.7

DRUM

Batu Air Hitam

(g)

Batu Minyak

Beku (g)

1910.2 1862.5

Sampel (A) + Drum (D) Berat (g)

Air Hitam + D 2439.5

Minyak Beku + D 2363.1

1st Cycle (B)

2nd Cycle (C)

First Cycle

(A (Air Hitam) B (Air Hitam )) X 100%

A (Air Hitam )

= ( 529.3 g 528.9 g ) X 100%

529.3

= 0.075 %

% retained after one 10min cycle (dry weight basis)

= 100 % - 0.075 %

= 99.9 %

(A (Minyak Beku) - B (Minyak Beku)) X 100%

A ( Minyak Beku )

= ( 500.6 g 498.2 g ) X 100%

500.6

= 0.479%

% retained after one 10min cycle (dry weight basis)

= 100 % - 0.479 %

= 99.5 %

Sampel (B) Berat (g)

Air Hitam 528.9

Minyak Beku 498.2

Sampel (B)+ Drum (D) Berat (g)

A & Air Hitam + D 2439.1

A & Minyak Beku + D 2360.7

Sampel (C) Berat (g)

Air Hitam 526.4

Minyak Beku 495.1

Sampel (C)+ Drum (D) Berat (g)

Air Hitam + D 2436.6

Minyak Beku + D 2357.6

(A-B) X 100% A

Second Cycle:

(B (Air Hitam) C (Air Hitam )) X 100%

B (Air Hitam )

= ( 528.9 g 526.4g ) X 100%

528.9 g

= 0.473 %

% retained after two 10min cycle (dry weight basis)

= 100 % - 0.473 %

= 99.5 %

(B (Minyak Beku) - C (Minyak Beku)) X 100%

C ( Minyak Beku )

= ( 498.2 g 495.1 g ) X 100%

498.2 g

= 0.622 %

% retained after two 10min cycle (dry weight basis)

= 100 % - 0.622 %

= 99.4 %

1.6 CONCLUSION

From the sample we have obtained and tests we have conducted, it can be

concluded, that the rock samples used were not weathered, based on the calculations and

the results of this test result. Tests carried out found, that the sample has more than 99% of

the value that indicates, the rock sample is in group very high durability based on Gambles'

Slake Durability Classification.

(B-C) X 100% B