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Put the sand into the oven at 110 ° C for ± 24 hours, chill it, and weighed.
4. Water Content
Prepare the pan in the dry condition and weighed it. Put 100 grams of fine aggregate into the pan and then weighed.
Put the pan which already filled with the fine aggregate into the oven with the temperature is 110°C for 24 hours.
After 24 hours, chill the pan which already filled with fine aggregate, then weighed. Note the results.
The water content of the aggregates is calculated by the formula:
4-2
with:
A = The weight before aggregate before put into the oven B = The weight before aggregate before put into the oven
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The Amount of Mud =
� �
x100
4.6.2. Coarse Aggregate
1. Determine the amount of mud in sand
Take 100gr oven-dried coarse aggregate split and put it into the pan.
Fill the pan with water until the split is submerged, stir for 1 minute and let stand for 1 minute.
Dirty water above the split is poured out but the split stays in the measured glass.
Then pour water into the measured glass, same as in process 1 – 3. Do it continuously until the water is clear.
After the water is clear, pour the water out and pour the split into the plate.
Dry the c split in the oven at 105°C – 110°C about 24 hours. Take the split from the oven and put in the cool desiccator.
After cooling the sand, measure the weight B gram.
Calculate the amount of mud in the Coarse Aggregate:
4-3
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2. Density and Absorption
Splits retained on ½” are taken then weighed as much as 1000 gr. The splits are soaked for 24 hours and washed thoroughly.
These splits in the water bucket are weighed but first the bucket should be weighed with the water.
The splits are dried using a cloth until reach the SSD Saturated Surface Dry, and then the split are weighed.
The splits are dried in the oven at 110° C until dry. Aggregate cooled in the desiccator with a temperature of 25°C,
and then weighed. Then the calculated density and absorption of aggregates as in
appendix A.4. 3.
Water Content Prepare the pan in the dry condition and weighed it.
Put 1000 grams of splits into the pan and then weighed. Put the pan which already filled with the splits into the oven with
the temperature is 110°C for 24 hours.
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After 24 hours, chill the pan which already filled with splits, then weighed. Note the results.
The water content of the aggregates is calculated by the formula: 4-5
with:
A = The weight before aggregate before put into the oven B = The weight before aggregate before put into the oven
4.7. Specimen Testing
Make the calculation and planning should be considered before make the specimen. The calculation and planning are called geopolymer concrete mix
design. Because there is no definitive determination of its manufacture, geopolymer concrete mix design was made by the method of weight ratio.
The percentage of aggregate, activator, metakaolin, and silica fume in this research was referred to the mix design of the thesis which was done by Efendi
2014 with t he title of the thesis is “Pengaruh Komposisi Solid Material Abu
Terbang dan Abu Sekam Padi pada Beton Geopolimer dengan Alkaline Activator Sodium Silikat dan Sodium Hidroksida” and from the research of Lisantono and
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Hatmoko 2009 with the title of the research is “The Compressive Strength of
Geopol ymer Concrete Made with Bagasse Ash and Metakaolin”
The amount of specimen that will be done is 18 specimens with the kind of variant such as shown in table 4.1
Table 4.1 The Amount of Specimens
Age of the Experiment Metakaolin : Silica Fume
Amount of the Specimens
25:5 50:5
75:5 14 Days
3 3
3 9
28 Days 3
3 3
9 The difference between geopolymer concrete and conventional concrete is in
the cement. Conventional concrete use cement while the geopolymer concrete replaces the cement with geopolymer pasta to bind the entire component.
Step to make geopolymer concrete: 1.
Prepare of Pozzolan The pozzolan in this experiment is metakaolin and silica fume. The
metakaolin is a material comes from the combustion of kaolin. Metakaolin will be burn in 800°C and after that it will be sieved in
sieves 100mm. Both metakaolin and silica fume are prepared according to the proportion that already planned.
