This code standardizes the testing methods for determining the strength of concrete, specifically detailing the procedure for finding the flexural strength (modulus of rupture) using beam specimens. It is extensively used by QA/QC engineers to verify concrete tensile strength for rigid pavements and flat slabs.
Covers the procedure for determining the flexural strength of hardened concrete by testing beams.
Quick Reference Values
standard specimen diameter150 mm
standard specimen length300 mm
rate of loading1.2 to 2.4 N/mm²/min
plywood strip thickness3 mm
plywood strip width12 mm
plywood strip lengthGreater than the length of the specimen
Key Formulas
fct = 2P / (π × d × l) — Splitting tensile strength (where P is max load, d is diameter, l is length)
Practical Notes
Specimens must be tested immediately after removal from water curing while they are still wet; drying out can significantly alter tensile test results.
Plywood packing strips are mandatory between the specimen and the machine platens to prevent local compressive crushing and ensure a true tensile failure.
Proper alignment using a jig is critical to ensure the load is applied exactly along the diametral plane.