How do I perform the ASTM C78 Flexural Strength test in ForneyVault®?

ASTM C78 is a standard test method for determining the flexural strength of concrete. Special care needs to be taken during setup to achieve accurate results.

This test method covers the determination of the flexural strength of concrete by the use of a simple beam with third-point loading.  These instructions apply to a beam with a 6" width, 6" depth, and 18" span length.

Prepare Beam for Testing

1. Turn the beam on its side so that the surface that was on top during molding is now on one of the vertical sides.
2. Mark the middle of the top of the beam.
3. Mark 3" to the left and right of the middle of the beam.
   1. These marks indicate where the upper anvils will contact the beam.
   2. The distance between the anvils is 6", or one-third of the span, hence "third-point loading."
4. Mark 9" to the left and right of the middle of the beam (the marks are 6" to the left of the left mark, and 6" to the right of the right mark).
   1. These marks indicate where the beam will contact the lower support anvils.
   2. Extend these lines vertically down the sides of the beam so that the beam can be properly placed on the lower support anvils.

Select Specimen in ForneyVault® ForneyLink®

1. Select Specimen using ForneyScan or SampleSearch
2. Select Measure to enter your Specimen's Span Length, Depth, Width, Defects, and Cure Conditions, if needed.  Select OK to record your values.
   1. Nominal depth, width, and span length measurements should already exist and can be used for running the test.

Load Beam into the Forney Testing machine. 

1. Center beam in the test machine on the support blocks, aligning the marks you made earlier with the lower support anvils.
2. Use Jog Advance to apply 3-6% of the estimated max load on the beam. 
3. Check the beam for gaps and cap, grind, or shim as needed.
   1. Press the Retract button to release the load if you need to remove the beam or add shims.

Start Test in ForneyVault ForneyLink

1. Use Jog Advance to advance the test machine's piston to touch the specimen.
   
   
2. The Jog Advance button turns yellow and displays "Jog Hold" indicating that the test machine's piston is being held in place.
   
   
3. Press the Load button to tare the load and reset the load back to zero.
   
   
4. When ready, press the Start Test button to begin the test.
   
   
5. Once completed, test results will be accessible in ForneyVault.