Determination of Relative Densities and Water Absorption of Coarse Aggregates
Experiment Title : Determination of relative densities and water absorption of coarse aggregates.
Objective : To determine the relative densities and water absorption of a coarse aggregate. Description of Sample : The sample used was naturally occuring riverside aggregate and was left to soak for 24 hours prior to the experiment. Apparatus Required A pycnometer – a pycnometer is a litre glass jar which has a conical screw on it 's lid, and a small aperature at the apex of the conical lid. The use of a pycnometer allows the same volume to be measured repeatedly. ● An electronic mass balance ● A water bottle ● A pan ● An oven
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Procedure
This experiment was carried out under conditions of constant temperature.
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The masses of an empty clean and dry pycnometer and pan were measured.
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The pycnometer was carefully filled with water until an upward meniscus is formed in the aperture. Surplus water was then removed to produce a downward meniscus.
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Then the mass of the water filled pycnometer was measured using the electronic mass balance. This value was then recorded.
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The sample of gravel was then added to the pycnometer until it took up roughly 60% of the pyncometer. The remaining 40% being occupied by water.
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The outside of the pycnometer was then dried thoroughly using tissue paper and then weighed using the balance. The mass was then recorded.
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The aggregate gravel was then removed, dried and placed in the pan. The mass of this pan containig the gravel was then found and recorded.
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Lastly the gravel was oven dried for a set period of time (1 week) and it 's mass was then recorded.
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Results
A = Mass of saturated surface dry sample = 0.766 kg B = Mass of pycnometer & sample & water = 1.9 kg C = Mass of pycnometer & water = 1.498 kg D = Mass of oven dry sample = 0.75 kg
Calculations
Relative density of oven dried sample = =
0.75 0.766−(1.9−1.498) D A−( B−C)
=
375 182
= 2.06
Relative density of saturated
Objective : To determine the relative densities and water absorption of a coarse aggregate. Description of Sample : The sample used was naturally occuring riverside aggregate and was left to soak for 24 hours prior to the experiment. Apparatus Required A pycnometer – a pycnometer is a litre glass jar which has a conical screw on it 's lid, and a small aperature at the apex of the conical lid. The use of a pycnometer allows the same volume to be measured repeatedly. ● An electronic mass balance ● A water bottle ● A pan ● An oven
●
Procedure
This experiment was carried out under conditions of constant temperature.
●
The masses of an empty clean and dry pycnometer and pan were measured.
●
The pycnometer was carefully filled with water until an upward meniscus is formed in the aperture. Surplus water was then removed to produce a downward meniscus.
●
Then the mass of the water filled pycnometer was measured using the electronic mass balance. This value was then recorded.
●
The sample of gravel was then added to the pycnometer until it took up roughly 60% of the pyncometer. The remaining 40% being occupied by water.
●
The outside of the pycnometer was then dried thoroughly using tissue paper and then weighed using the balance. The mass was then recorded.
●
The aggregate gravel was then removed, dried and placed in the pan. The mass of this pan containig the gravel was then found and recorded.
●
Lastly the gravel was oven dried for a set period of time (1 week) and it 's mass was then recorded.
●
Results
A = Mass of saturated surface dry sample = 0.766 kg B = Mass of pycnometer & sample & water = 1.9 kg C = Mass of pycnometer & water = 1.498 kg D = Mass of oven dry sample = 0.75 kg
Calculations
Relative density of oven dried sample = =
0.75 0.766−(1.9−1.498) D A−( B−C)
=
375 182
= 2.06
Relative density of saturated