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Chapter IV

SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

This chapter presents the summary of results, conclusions, and

recommendations appropriate to the findings of the study.

Summary of findings

This study aimed to determine the physical and mechanical properties of

coarse aggregate from Mainit river and Kalambis river of Caibiran, Biliran.

The following are the result of the study:

Physical properties of coarse aggregate

Specific gravity. The values of specific gravity of coarse aggregate from Mainit

river is 2.173% (DRY), 2.215% (SSD) and 2.268% (Apparent). And the values of

specific gravity of coarse aggregate from Kalambis river is 2.075% (DRY), 2.109%

(SSD) and 2.148% (Apparent). The typical value for specific gravity of natural coarse

aggregate is 2.6%.

Absorption. The values of absorption of coarse aggregate from Mainit river is

1.937%. And the values of absorption of coarse aggregate from Kalambis river is

1.645%.

Therefore, both of the sample of coarse aggregate is not highly absorptive (less than

5% absorption) and does not require more asphalt binder making the resulting hot

mix asphalt less expensive.

Unit weight. the values of unit weight of coarse aggregate from Mainit river is

1320 kg/m3 (loose) and 1486 kg/m3 (rodded). And the values of unit weight of coarse

aggregate from Kalambis river is 1281 kg/m3 (loose) and 1414 kg/m3 (rodded).

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Determining the value for unit weight is necessary for use for many methods of

selecting proportions for concrete mixtures.

Soundness. The value of soundness of coarse aggregate in Mainit river is

6.85%. And the value of soundness of coarse aggregate in Kalambis river is 7.27%.

Therefore, both of the sample of coarse aggregate had complied to the standard

specification for soundness which is 12.0% max. The quality of soundness of

aggregate or its resistance to the forces of weathering is one of the most important

considerations in the selection of a material for highway construction.

Abrasion. The value of abrasion loss of coarse aggregate from Mainit river is

29.72% and from Kalambis river is 28.52%.Therefore, both of the sample of coarse

aggregatre had complied to the standard specification for abrasion which is 40.0 %

max. The percentage is a measure of the degradation or loss of material as a result

of impact and abrasive actions.

Clay lumps. The clay lumps of coarse aggregate from Mainit river is 0.2 %.

And the clay lumps of coarse aggregate from Kalambis river is 0.17%. Therefore both

of the sample of coarse aggregate had complied to the standard specification for clay

lumps which is 1.0 % max. Clay lumps are materials that are easily crumbled or

mashed with the fingers.

Moisture Content. The moisture content of coarse aggregate form Mainit river

is 7.21% and from Kalambis river is 4.89%. Obviously this aggregate has big amount

of moisture content because its from a river.

Wash loss on no. 200. The wash loss on no. 200 sieve of coarse aggregate

from Mainiti river is 3.15% and from Kalamibis is 7.44%. Therefore, the target had not

57

been achieved for both sample of coarse aggregate, where the standard specification

for wash loss on no. 200 is 1.0 max.

Mechanical properties of coarse aggregate

Sieve analysis. the coarse aggregate from Mainit river passing 3 inch sieve

size is 100%, passing 21

2 inch sieve size is 100%, passing 2 inch sieve size is 100%,

passing 11

2 inch sieve size is 54%, passing 1 inch sieve size is 3%, passing ¾ inch

sieve size is 3%, passing ½ inch sieve size is 3%, passing 3/8 inch sieve size is 3%,

passing no.4 sieve is 3%, passing no.8 sieve is 3%, passing no.16 sieve is 3%,

passing no. 200 sieve is 3%. And the coarse aggregate from Kalambis river passing

3 inch sieve size is 100%, passing 21

2 inch sieve size is 100%, passing 2 inch sieve

size is 100%, passing 11

2 inch sieve size is 69%, passing 1 inch sieve size is 8%,

passing ¾ inch sieve size is 8%, passing ½ inch sieve size is 7%, passing 3/8 inch

sieve size is 7%, passing no.4 sieve is 7%, passing no.8 sieve is 7%, passing no.16

sieve is 7%, passing no. 200 sieve is 7%. Therefore, target grading for coarse

aggregate of bothsample had been achieved, where the range for 3” sieve size is

100%, for 2 ½ “ is 90-100%, for 1½” is 25-60%, for 3/4 “ is 0-10%, and for 1/2“ 0-5%.

Comparison of mechanical and physical properties of coarse aggregates to

acceptable standards

Abrasion. The value of abrasion of coarse aggregate from Mainit river is

29.72% and from Kalambis river is 28.52%. Both samples of coarse aggregate

complied to the standard specification for Abrasion which is 40.0 max.

Specific gravity. The value of Specific gravity of coarse aggregate from Mainit

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river is 2.173%(OD), 2.215%(SSD), 2.268%(APP) and from Kalambis river is

2.075%(OD), 2.109%(SSD), 2.148%(APP). There are no standard specification for

specific gravity, but there is a typical value for specific gravity of natural coarse

aggregate which is 2.6%.

Absorption. The value of absorption of coarse aggregate from Mainit river is

1.937% and from Kalambis river is 1.645%. The samples of aggregate is not highly

absorptive because its value of absorption is less than 5%.

Unit weight. The value of unit weight of coarse aggregate from Mainit river is

1320 kg/m^3 (Loose) and 1496 kg/m^3 (Rodded) and from Kalambis river is 1281

kg/m^3 (Loose) and 1414 kg/m^3 (Rodded). There are no specification for unit weight

but the values of unit weight is necessary for use for many methods of selecting

proportions for concrete mixtures.

Soundness. The value of soundness of coarse aggregate from Mainit river is

6.85% and from Kalambis river is 7.27%. Both samples of coarse aggregate had

complied to the standard specification for soundness which is 12.0 max.

Moisture Content. The value of moisture content of coarse aggregate from

Mainit river is 7.21% and from Kalambis river is 4.89%. The aggregate has big

amount of moisture content because it's from a river. The value of moisture content

is used to adjust the ratio of concrete mixture, so that it can't affect to the concrete

structure.

Wash loss on no.200. The value of wash loss on no. 200 sieve of coarse

aggregate from Mainit river is 3.15% and from Kalambis river is 7.44%. Both of the

sample of coarse aggregate had not complied to the standard specification for the

wash loss on no. 200 sieve which is 1.0 max.

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Sieve Analysis. The coarse aggregate from Mainit river and Kalambis river had

complied to the requirements for the size number specified for coarse aggregate.

Good gradation of aggregates is one of the most important factors for workable

concrete.

Conclusion

The physical and mechanical properties of aggregate is very important

because it indicates the strength and duarability of the coarse aggregate for concrete

mixture. Both of the sample of coarse aggregate from Mainit river and Kalambis river

had complied to the standard specification for specific gravity, absorption loss,

moisture content, clay lumps, and sieve analysis, except on “wash loss on no. 200”

where the values of both sample are greater than the maximum value of standard

specification for the test. To achieve a quality of an aggregate it needs to comply in

specification of all test for coarse aggregate. Therefore, this aggregates are not

suitable for some types of construction. These aggregates can only be used if it meets

the requirement of contract for construction base on its physical and mechanical

properties.

Recommendations

From the conclusions drawn, the following recommendations were made:

1. Values of properties of aggregate should be considered when using the

aggregate for concrete mixture.

2. Base on the result of both aggregate on soundness test, the aggregates

can resist to the forces of weathering.

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3. The value of moisture content of both aggregate can be used to adjust the

ration of concrete so that it can’t affect to the concrete structure.

4. Both of the aggregates is not highly absorptive,

5. Both of the aggregates does not require more binder because its not highly

absorptive, making the resulting concrete less expensive.

6. The value of unit weight of aggregates is necessary for use for many

methods of selecting proportions for concrete mixtures.

61

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"properties of aggregate." Encyclopædia Britannica. Encyclopædia Britannica

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"materials testing." Encyclopædia Britannica. Encyclopædia Britannica Ultimate

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http://www.in.gov/indot/files/chapter_03.pdf, retrieved on 09-03-14

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by Drying” ASTM 2004 Volume 04.02 Concrete and Aggregates

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Concrete and Aggregates

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ASTM 2004 Volume 04.02 Concrete and Aggregates

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Mineral Aggregates by Washing” ASTM 2004 Volume 04.02 Concrete and

Aggregates

“C 88 – 99a Standard Test Method for Soundness of Aggregates by Use of Sodium

Sulfate or Magnesium Sulfate” ASTM 2004 Volume 04.02 Concrete and

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APPENDICES