Skripsi
PENGARUH PH AIR DAN PENAMBAHAN FLY ASH PADA KUAT TEKAN BETON F’C 35 MPA
In the manufacture of concrete, water is one of the important materials, because water will react with cement and become a mortar or paste to bind the concrete. Water that is good for use in the manufacture of concrete is water that does not contain acids or bases. Therefore, good water for making concrete is water that has a neutral pH with a value of 7. Besides cement water is also included as one of the important materials in making concrete. Cement is used because it has a binding capacity to coarse aggregate, fine aggregate, and other materials when mixed with water. Along with the times, a cement substitute material was found, namely fly ash. Fly ash is the combustion residue from coal in the form of fine ash. Its physical form is like cement and has some binder content such as cement. The purpose of this study was to determine the effect of the use of variations in the pH of the water used, namely pH 3, 5, 7, 9, and 11 in the manufacture of concrete f'c 35 MPa and fly ash substitution in pH 3 concrete as much as 10% and 20% to acid concrete. For alkaline concrete, the pH is 11 with 10% and 20% fly ash substitution. This research was conducted in the Structure Laboratory of Sriwijaya University. The test object used was a cylinder with a diameter of 10 cm and a height of 20 cm with 3 samples for each variation. Compressive strength testing was carried out at the age of 7 and 28 days after treatment. The results of this study are the compressive strength decreased for the use of acid and alkaline pH and the addition of compressive strength due to substitution of fly ash. The average compressive strength produced at the age of 7 days for pH 7 was 28.52 Mpa. For pH 3 and 5 of 23.89 MPa and 25.71 MPa, it decreased by 16.23%% and 9.85%, respectively. The concrete using alkaline water 9 and 11 produced compressive strength of 26.31 Mpa and 23.13 Mpa, respectively, decreased by 7.74% and 18.89%. For concrete using water pH (Neutral) on day 28, The average compressive strength produced is 35.77 MPa. Meanwhile, concrete using acid water 3 and 5 produced compressive strength of 28.09 Mpa and 30.04 Mpa, respectively, decreased by 21.47% and 16.01%. The concrete using alkaline water 9 and 11 produced compressive strength of 30.51 Mpa and 27.84 Mpa, respectively, decreased by 14.7% and 22.16%. For fly ash substitution in acid concrete, the compressive strength of concrete increased due to the substitution of fly ash by 10% and 20%. For the 7 days, the values produced by the substitution of 10% and 20% fly ash were 27.41 Mpa and 29.58 Mpa, respectively. For the 28 days, the values produced by the substitution of 10% and 20% fly ash were 29.83 Mpa and 33.31 Mpa, respectively. For the substitution of fly ash in alkaline concrete, the compressive strength of concrete also increases in compressive strength. For the 7 days, the values produced by the substitution of 10% and 20% fly ash were 27.93 Mpa and 29.19 Mpa, respectively. For the 28 days, the values produced by the substitution of 10% and 20% fly ash were 28.69 Mpa and 32.34 Mpa, respectively. Key Words: compressive strength of concrete, water, pH, acid, base, fly ash
Inventory Code | Barcode | Call Number | Location | Status |
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2207004400 | T81323 | T813232022 | Central Library (Referens) | Available |
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