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Glenn Love
01-29-2006, 06:43 AM
I need to convert cubic yards of 57 rock to tons. I don't know the density of 57 rock.

Thank you
Glenn Love

Robert Fogt
01-29-2006, 01:50 PM
I could not find that density listed online either.

Would it be possible to weigh a certain amount of it? For example, fill a milk jug and weigh it. You could calculate the density from that.

Unregistered
05-10-2006, 05:30 AM
density of dry gravel (1/4" to 2") is 1682 kg/cm or 105 pcf

Unregistered
08-13-2006, 04:55 PM
approx 18 CY is equal to 22 tons of 57 rock

Unregistered
05-05-2007, 10:02 AM
what is the density of a rock

Mrs X
05-06-2007, 01:12 AM
"Density" is how much space something takes up for how much it weighs. Rocks are heavy, they have a high density - they sink in water. Polystyrene is light, it has a low density, it floats in water. Does this answer what you were asking? :)

iq of 150
07-07-2007, 08:36 AM
whats it acutial formula of measuring density of a rock i cant find it any where

Robert Fogt
07-07-2007, 10:40 AM
You take a known amount, and weigh it.

For example, take a 5 gallon bucket, fill it with the gravel, and weigh it. Then subtract the weight of the empty bucket.

Lets say the 5 gallon bucket weighs 100 pounds.

100 pounds / 5 gallons = 20 pounds/gallon

You now have the density in pounds/gallon, and you can convert that to kg/L or whatever else you need it in.

Robert Fogt
07-07-2007, 10:43 AM
I should point out that its not how they do it in the laboratory. They would add the rock to water and measure the volume of water that was displaced.

But I assume you're not in a laboratory so my bucket idea is your best bet.

mr. basalt
11-01-2008, 04:00 AM
I own a rock quarry, and wanted to know density of my rock. we filled a tub, then dipped in a rock slowly which weighed 164.5 pounds, the rock displaced 6.9 gallons of water. water has 231 cubic inches per gallon , so my rock had 1593 cubic inches. I then divided cubic inches by weight so i know it takes 9.6389 cu.in. to make 1 lb. Then I divided 1593 by 9.6389 and I come up with rock density of just over 165 lb. sq. ft. what you think?

Cly
01-27-2009, 04:59 PM
If you take your 6.9 gallons x 8.34 lbs/gal for water, you get 57.546 lbs (if your rock were water it would weigh this much). Since it's rock and weighs 164.5 lbs, you divide it's 164.5 lb weight by the weight of the water it displaces, 57.546 lbs, and you get a SPECIFIC GRAVITY of 2.8586, meaning your rock is 2.8586 times more dense than water.
Hope this helps.

Unregistered
05-28-2009, 07:20 PM
in the lab we dnt use a water displacement method, it no where near accurate enough we use a specific gravity method. this is a geology lab doing exploration i work in. we weigh our rocks on a scientific balance the weigh it suspended in water and use the formula, but for that u would need to take into consideration the water density at different tempretures.

JohnS
05-29-2009, 03:48 AM
in the lab we dnt use a water displacement method, it no where near accurate enough we use a specific gravity method. this is a geology lab doing exploration i work in. we weigh our rocks on a scientific balance the weigh it suspended in water and use the formula, but for that u would need to take into consideration the water density at different tempretures.

This is the correct method to find the intrinsic density of the rock (just the rock, no airspaces).

But questions here usually concern a pile of rocks, the volume of the pile and the weight of the pile. Bulk and intrinsic density always differ for broken up materials based on the airspace between pieces. When the material is ground finely, bulk density is also called powder density.

Neither value is "wrong" but you have to know which value is most responsive to the question.

Unregistered
08-23-2009, 07:40 AM
You are handed a rock which weighs 19.63 grams, and has a volume of 6.50 cm3. What is the density of the rock?

Unregistered
09-01-2009, 08:44 AM
Actually, it's very easy.

If you have a kitchen scale and a measuring cup, you can figure out density. I'll tell you how using grams, but it is easy to convert when you are done.

Find a rock that weighs just under 450 grams/1 lb. It can be any weight, really, but I am using 450 because my scale only goes to 450 grams. Record the weight of the rock exactly.

Take your kitchen measuring cup and fill it to about the 300cc or ml mark. Put the rock in the cup and make sure the water covers it completely. Record the new water level exactly.

My rock weighed 495g. The water it displaced was 150 cc. 495 divided by 150 = 3.3

So the density of my rock was 3.3 g/cc, or just 3.3

I took another rock, a small one this time. I also have a shot glass with cc's on it. I filled the shot glass to 15cc with water, put it on the scale and zeroed it out. I then dropped the little rock in and the water level went to 20 and the weight went to 16.6g. 16.6 divided by 5 = 3.32.

I understand this is a normal range for rock density.

Unregistered
09-28-2009, 09:46 AM
I own a rock quarry, and wanted to know density of my rock. we filled a tub, then dipped in a rock slowly which weighed 164.5 pounds, the rock displaced 6.9 gallons of water. water has 231 cubic inches per gallon , so my rock had 1593 cubic inches. I then divided cubic inches by weight so i know it takes 9.6389 cu.in. to make 1 lb. Then I divided 1593 by 9.6389 and I come up with rock density of just over 165 lb. sq. ft. what you think?

its more like 178 #/cubic foot.....here's the simple math:

6.9/7.48 equals 0.92 cubic feet volume.

164.5/.92 yields 178 pounds per cubic foot.

guest
04-16-2010, 02:25 AM
There is an ASTM standard for that: C127 Standard test method for Density, Specific Gravity and Absorbtion of Coarse Aggregates.
The formulas are:
Relative density (Specific Gravity)(Oven Dried)=A/(B-C)
Relative density (specific gravity) (surface dried)=B/(B-C)
Apparent relative density (apparent specific gravity)=A/(A-C)
Density(oven dried)=997.5 A/(B-C) (kg/m3) or 62.27 A/(B-C) (lb/ft3)
Density(Surface dried)=997.5 B/(B-C) (kg/m3) or 62.27 B/(B-C) (lb/ft3)
Apparent Density 997.5 A/(A-C) (kg/m3) or 62.27A/(A-C) (lb/ft3)
Absortion(%)=[(B-A)/A]x100.
You can also take a sample to an accredited materials lab and get a certified report signed by a PE. Hope this helped.

Unregistered
09-08-2010, 10:10 AM
There is a difference of the density of the rock itself and the bulk density. Using the water displacement method gives you the density of the rock itself which is constant no mater what the size of stone. Using the other methods will give you the bulk density which will change depending on the size of the chunks. For construction and hauling purposes you will most likely want the bulk density.

Unregistered
11-05-2011, 08:13 AM
No, that's not right.