I have the data of adsorption and desorption curve at relative pressure from 0.10 to 0.99 at every 0.10 interval. Can anyone guide me how I can calculate the total pore volume of concrete samples.
usually we get text file contain all related data (BET surface area, pore volume,.....)
I agree with Abdelaal Saiyd and Mohamed Bayati ....
So, I loaded the following vip book.
Hi Vivek,
First, make sure your 'Quantity Adsorbed' is in cm^3/g, or convert to cm^3/g if it is in mmol/g. Now total pore volume (TPV) is calculated as follows:
TPV = Qsat*(Pvap/Pliq)
Where Qsat is the N2 adsorption quantity (in cm^3/g) at the relative pressure would like to calculate it from, often 0.97 or above is used. Pvap is the density of N2 vapour at STP (1.2504 g/L) and Pliq is the density of liquid N2 at its boiling point (807 g/L). Subbing in numbers:
TPV = X cm^3/g * (1.2504/807)
I hope this is helpful to you. Often there is a feature in the software to do this calculation for you.
As indicated before there is usually a very simple way to approximate the "total" pore volume by applying some simple conversions between cm3/g STP (usual instrument units) to liquid volume to be found in the software. However, if the isotherm has not plateau'd by 0.99 p/p0 then this is not a total pore volume but a partial volume up to pores of equivalent size. Even then, if there were a plateau, the pore volume is approximate since all of the nitrogen adsorbed does not assume the density of bulk liquid, especially in smaller pores.
It is normal to evaluate concrete by mercury porosimetry for pore size/volume distributions, since gas adsorption can only provide information
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