PROPERTIES OF MATERIAL EXPERIMENTAL REPORT EXAMINATION OF

SUBSTANCES AND QUALITY OF CONCRETE

MODULE 6

EXAMINATION OF MOISTURE CONTENT OF COARSE AGGREGATE

KELOMPOK 31

Danny TirtaWinata 1306437025

Sabrina NurulHidayah 1306437145

Daniel AndigaWibisana 1306437076

Ahmad Haekal 1306437151

Date of Experiment : September 28, 2013

Experiment Assistant : Suryo Wijiono

Date of Approval :

Score :

Assistant’s Signature :

LABORATORY OD STRUCTURE AND MATERIAL

CIVIL ENGINEERING DEPARTEMENT

ENGINEERING FACULTY

UNIVERSITAS INDONESIA

DEPOK 2013

EXAMINATION OF MOISTURE CONTENT OF COARSE AGGREGATE

I. Objective

This experimental work is to determine the moisture content of aggregate by drying. Moisture

content is the ratio of weight of moisture in aggregate and the weight of dried aggregate. This

experimental work has objective to adapt dose of concrete if the humidity of concrete changes.

II. Material

MAXIMUM GRAIN SIZE OF

AGGREGATE

MINIMUM WEIGHT OF DRIED

AGGREGATE SAMPLE

(mm) (inch) (kg)

6,3 ¼ 0,5

9,5 3/8 1,0

12,7 ½ 2,0

19,1 ¾ 3,0

25,4 1 4,0

38,1 1 ½ 5,0

50,8 2 8,0

63,5 2 ½ 10,0

76,2 3 13,0

88,9 3 ½ 16,0

101,6 4 25,0

152,4 6 50,0

III. Apparatus

1. Scale/balance

2. Oven with temperature adjustment to heat up the specimen up to (110 ± 5) ºC.

3. Large enough capacity of anti-corrosive metal tray to dry the specimen.

IV. Procedure

1. The weight of the container is measured with a scale.

2. The coarse aggregate is separated from the mixed aggregate using the ¾ inch sieve.

3. The coarse aggregate is poured into the container until it is full, and the total weight is

measured.

4. The container of coarse aggregate is then put in the oven for 24 hours to be dried.

5. After the container of coarse aggregate is taken out of the oven, the total weight is

measured again.

V. Observation and Data Calculation

Weight of container = 465 gram (w1)

Total weight of coarse aggregate and container = 10,755 gram (w2)

Weight of coarse aggregate (w3) = (w2 – w1) = 10,755 – 465 = 10,290 gram

Weight of dried coarse aggregate and container = 10,388 gram (w4)

Weight of dried coarse aggregate (w5) = (w4 – w1) = 10,338 – 465 = 9,873 gram

MoistureContent ofAggregate

¿(weight of aggregate – weight of dried aggregate )

weight of dried aggregate× 100 %=

(10,290−9,873 )9,873

× 100 %=4,22 %

VI. Experimental Analysis

i. Analysis of Experiment

The examination of moisture content of coarse aggregate is done to find the percentage of

humidity in coarse aggregate. The method used in this examination is drying. Before

calculation the moisture of aggregate, the preparation has to be done one day before the

examination, so there is enough time to dry the aggregates. The coarse aggregates are

obtained from a pile of mixed aggregates located outside the lab. These aggregates have

been exposed to different kinds of conditions because they are located outside in an open

area. They have been exposed to cold and night temperatures, and rain. So they are

suitable for this experiment, which measures the moisture content of coarse aggregate.

The weight of coarse aggregates that is used in this examination is 10,290 grams. To

separate the coarse aggregates from the mixed aggregates, they first have to be filtered

using the ¾ inch sieve. Using the ¾ inch sieve to filter the aggregates will separate the

coarse aggregates from the fine aggregates and other small materials. The coarse

aggregate is then placed in a container. But the weight of the container has to be

measured before so that the net weight of the aggregate can be determined. After that, the

container full of coarse aggregates is put in the oven for 24 hours. When 24 hours have

past, the container filled with the coarse aggregates is measured again. Then finally all

the data for this examination can be collected and processed.

ii. Result Analysis

When the difference of weight between the humid aggregate and dry aggregate is calculated,

the moisture of coarse aggregate is determined. From there, the percentage of moisture

content of the aggregate can be determined. The moisture content is basically the ratio of

weight of moisture to the weight of dried aggregate. According to this examination and the

aggregates that are used, the moisture content of coarse aggregate is 4.22 percent. This

number can change depending on the level of humidity of the aggregates. The humidity of

aggregate is proportional to the moisture content

If the moisture content is high, then the level of humidity is also high and vice versa.

iii. Error Analysis

1. When the students use the sieve to filter the mixed aggregates, some fine

aggregates could have fallen into the coarse aggregate container because the

students did not properly filter the aggregates

2. One parallax error that cannot be considered as the tool’s or student’s fault is

when the coarse aggregate is put in the oven; the oven’s door might be open many

times because many people are using it too, which can affect the temperature of

the oven.

VII. Conclusion

The objective of this examination determines the moisture content of coarse aggregate in

percentage. And our coarse aggregate that weighs 10,290 grams has a moisture content of 4.22%.

VIII. References

American Society for Testing and Materials. “Standards Test Method for Total

Evaporable Moisture Content of Aggregate by Drying”, No. ASTM C 566 – 97.

Annual Book of ASTM Standards, Vol. 04.02.

BadanStandarisasiNasional. “MetodePengujian Kadar Air Agregat”, SNI 03-1971-

1990.

PROPERTIES OF MATERIAL EXPERIMENTAL REPORT EXAMINATION OF

SUBSTANCES AND QUALITY OF CONCRETE

MODULE 10

RESISTANCE TO DEGRADATION OF SMALL-SIZE COARSE AGGREGATE BY

ABRASION IN THE LOS ANGELES MACHINE

KELOMPOK 31

Danny TirtaWinata 1306437025

Sabrina NurulHidayah 1306437145

Daniel AndigaWibisana 1306437076

Ahmad Haekal 1306437151

Date of Experiment : September 28, 2013

Experiment Assistant : Suryo Wijiono

Date of Approval :

Score :

Assistant’s Signature :

LABORATORY OD STRUCTURE AND MATERIAL

CIVIL ENGINEERING DEPARTEMENT

ENGINEERING FACULTY

UNIVERSITAS INDONESIA

DEPOK 2013

RESISTANCE TO DEGRADATION OF SMALL-SIZE COARSE AGGREGATE BY

ABRASION IN THE LOS ANGELES MACHINE

I. Objective

This experimental work is intended to determine resistance to degradation of small-size coarse

aggregate by abrasion using Los Angles Machine The abrasion of aggregate is stated in ratio of

the weight of abrasive material passed sieve No. 12 to its initial weight (in percentage).

II. Material

Sieve

Weight for each

Gradation of Specimen (gram)

Passed

(mm)

Retained (mm) B

19.05 12.7 2500

12.7 9.51 2500

III. Apparatus

1. Los Angeles Machine; consists of cylindrical steel with a cap in both side with 71 cm

(26”) of diameter and 50 cm (20”) of length. The cylindrical steel is supported on two-

continuous short shafts, and rotates in a horizontal axis. The cylindrical has a hole to

input the specimen. The cover is set precisely so that the surface its inner surface, a steel

shaft lays perfectly in transverse direction with 8.9 cm (3.56”) of height.

2. Sieve No. 12

3. Scale/balance

4. Steel balls with 4,68 cm (1.84”) of average diameter and self weight at around 390-445

gram.

5. Oven with adjustable temperature (110 ± 5) ºC to heat up the aggregate.

IV. Procedure

1. Aggregates and all the steel balls are put in the Los Angeles Machine.

2. The machine is turned on to rotate for 15 minutes.

3. After the rotation is finished, the aggregate is poured out of the machine into a container

4. The aggregate is filtered using No. 12 sieve

5. The retained materials are washed properly and then put in the oven for 24 hours to be

dried.

6. After 24 hours, the weight of the aggregate is measured again.

V. Observation and Data Calculation

Initial weight of aggregate = 5000 grams

Weight of container = 262 grams

Weight of retained sieve No. 12 of the aggregate = 3,586 – 262 = 3,324 grams

Abrasion=a−ba

×100 %

a = initial weight of the aggregate (gram)

b = weight of retained sieve No. 12 of the aggregate (gram)

Abrasion=5,000−3,3245,000

×100 %

¿33.52 %

VI. Experiment Analysis

i. Analysis of Experiment

This experiment measures the resistance of small size coarse aggregate to degradation by

abrasion. The Los Angeles machine will break parts of the coarse aggregates. The weight

is then measured to determine how much of the coarse aggregate can retain abrasion. The

pure weight of small coarse aggregate is 5,000 grams. The aggregate is put in the Los

Angeles machine for 15 minutes. After 15 minutes, some of the aggregates turn into even

smaller aggregates and dust or sand. The abrasion inside of the machine is caused by the

steel balls that crush the aggregates. To separate the fine aggregates from the small

aggregates, No. 12 sieve is used. To help the filtering process, running water is also used

to help push the aggregates through the sieve. After the aggregates are filtered, they are

put in the oven for a whole day to be dried. The dried weight after 24 hours is of course

less than the initial weight because physically, it is obvious that the aggregates become

even smaller and some even turn into sand because of abrasion.

ii. Result Analysis

This experiment determines the percent of aggregates lost during abrasion. According to

this experiment, 33.52% of 5,000 grams of aggregates are lost during the process of

abrasion. The percentage of abrasion is the ratio of weight of aggregates retained by No.

12 sieve to its initial weight. The percent of abrasion can change depending on the length

of the process, strength of the aggregates, and number of steel balls that are placed inside

the machine.

iii. Error Analysis

1. Some materials might have fallen on the floor when the aggregates are poured

from the machine to the container

2. Some aggregates could also have fallen out when they are washed and filtered

through the sieve.

VII. Conclusion

This experiment shows that to calculate the percent of abrasion, the weight retained from

the Los Angeles machine and No. 12 sieve is needed, as well as the initial weight of the

aggregate. According to the amount of aggregates that is used, the percentage of abrasion

of 5,000 grams aggregate is 33.52%.

VIII. References

American Society for Testing and Materials. “Standards Test Method for Resistance to

Degradation of Small-Size Coarse Aggregate by abrasion and Impact in the Los

Angeles Machine”, No. ASTM C 131 – 03.Annual Book of ASTM Standards,

Vol. 04.02.

Attachment

Photo 1. Los Angeles Machine

Photo 2. Washing and filtering aggregates using No. 12 sieve.