The split-tensile (Brazilian) test loads a standard cylinder along two diametrically-opposite lines until it splits; the indirect tensile strength is fct = 2P/(πLD). It is the standard way to characterise concrete tensile strength (used in cracking and shear-related assessments) since a direct tension test on concrete is impractical.
Key Requirements
•Standard cylinder (150 mm dia × 300 mm), cured per Clause 4
•Apply load through packing strips along two opposite generators (line loading), centred
•Controlled rate of loading on a calibrated machine (IS 14858)
•Split tensile strength fct = 2P / (π·L·D)
•Report individual and average values; note tensile strength ≪ compressive strength
Formulas
f_ct = 2·P / (π·L·D)
Split (indirect) tensile strength from the splitting load