ASTM C78 addresses the flexural testing of concrete used in the construction of slabs and pavements with a "third-point" style flexure apparatus. Sampling and specimen preparation for fresh concrete taken in the field is covered in ASTM C31; sawed specimens taken from cured material are discussed in ASTM C42; and for specimens made in the lab are referenced in ASTM C192. We suggest referencing the instructions found in the ASTM C78 for the loading rates, proper specimen orientation, and application of preload to assure "gap-free" contact between the specimen and fixture.