1. Larry Rowland Guest

## Cement Bulk Density

I need to convert silo volume to weight of the portland cement stored there. The density rule of thumb I have used in the past is in question and I cannot find any definitive reference.

What is the bulk desity pounds/cubic^3 or kg/m^3:
After conveying pneumatically?
After it has time to settle in the silo?

I need general guidlines for extimating purposes and am aware of the many variables that affect this value.

I would appreciate anyone with portland cement experiance to comment on this question.

2. dear Larry,

I had a change to measure the stored density of 2 inverted cone silos in Antwerp,which were 100 % empty when started.
The loaded mass of cement (I am not aware of the type) was measured by the draft measurements of the barges that brought in the cement and were pumped into the respective silo.

The volume of cement in the silo was measured with a plate on a rope from the top and then calculated from the silo drawings.
The measurement was taken approx 2 weeks after filling, while the filling itself took about 2 weeks for each silo.
The measurement therefore has to be taken as almost completly settled.
(later on we found out that the life content of the silos wasbetween 8500 and 9000 tons, leaving a dead load of about 1500 tons)

The results were:

6500 m3 -9667 tons --> 1534.4 kg/m3
6572 m3 - 10500 tons -- 1597.7 kg/m3

For fluidized cement (after pneumatic conveying and at atmospheric conditions), the density should be between 1100 and 1200 kg/m3

As the variation in bulk density for cement can be as big as 1.45 times, the actual conditions are of great influence.

Hope to have helped you a little bit
have a nice day
teus

3. Larry Rowland Guest

## Cement Density

Thank you for the information Teus. These numbers are pretty close to what I have used as a rule-of-thumb.

The interesting thing is that I've gotten a wide range of answers from different sources. Most seem to be close to your aaproximate average of 1566 kg/m3.

It would be great to see an article on the topic. I'll Check with the PCA.