Testing flexural strength and compressive of tile joint grout products

The main standard BS EN 13888 say to test the flexural strength and compressive of tile joint grout products as per BS EN 12808-3. Let see how to test it:

Prepare three prismatic specimens 40 mm x 40 mm x 160 mm using the tile joint grout by mixing as per manufacturer specification

Subject the curing and conditioning as per the standard.

Test the flextural strength of specimens. 

The flexural strength (Rf ) = 1.5 Ff L / b^3 in N/Sqmm

Whereas:

b = the length of the side of the square section of the prism, in millimetres;

Ff  = the load applied to the middle of the prism at fracture, in newtons

L = the distance between the supports, in millimetres.

The compressive strength (Rc) = Fc/1600 = N/Sqmm

Whereas:

Fc = the maximum load at fracture, in newtons;

1600 = 40 mm x 40 mm is the area of the platens or auxiliary plates, in square millimetres.

For minimum requirement of strength, visit: https://annayyachandrashekar.blogspot.com/2018/08/requirement-of-tile-joint-grouting.html

Many thanks for google.com, from where the details are collected.