NF P12-102/A1*NF EN 772-2/A1:2005 Methods of test for masonry units - Part 2 : determination of percentage area of voids in masonry units (by paper indentation)
2005NF P12-102/A1*NF EN 772-2/A1:2005 Methods of test for masonry units - Part 2 : determination of percentage area of voids in masonry units (by paper indentation)