At Pulice – a FlatironDragados company, we prioritize operational excellence and safety.
When crews talk about “beam breaking,” they’re referring to on-site verification of concrete strength per ASTM C78, the standard test method for flexural strength of concrete. In practical terms, the test helps confirm whether concrete placed on a project can perform as required by the specification when subjected to bending stress. That matters most on pavement and other flatwork where flexural performance is directly tied to durability, crack resistance and long-term serviceability.
Recently, our materials testing subcontractor, Certerra and our subsidiary McNeil Brothers conducted beam breaking for our Mesa Gateway Airport Runway 12R-30L Reconstruction project.
As Certerra Physicist Loren Aldridge explains: “The process begins with a molded beam specimen that is typically 6 inches wide, 6 inches deep and 21 or 22 inches long. The beam is prepared so the contact surfaces are as plane as possible, then stored in temperature-controlled mineral-lime saturated water while it matures.” He stresses that the curing environment is important because it helps the specimen develop strength under controlled conditions before testing. For additional reference, the specimen is also weighed so technicians can calculate density in pounds per cubic foot.
During testing, the beam is loaded in a machine with support blocks spaced 18 inches apart and loading blocks spaced 6 inches apart. Before the load is applied, technicians verify specimen planeness with feeler gauges and, when permitted within tolerance, use leather shims at the contact points. The specimen is kept moist throughout the procedure, typically with a spray bottle, and the load is applied at a controlled rate until rupture occurs. Aldridge describes that step plainly: “Once the specimen is verified and centered, we begin the test by applying a load of 125-175 PSI until rupture occurs.” After failure, the team records the maximum load at rupture, measures the beam dimensions and calculates the modulus of rupture in psi for official reporting.
Beam testing at Pulice provides clear benefits. It offers our teams an objective way to confirm that concrete performance meets project needs, moving beyond mix design assumptions. This ensures quality control by identifying if field practices like batching, placement, and curing deliver the desired outcome. Safety is also enhanced by verifying the concrete’s strength before it is put into service. Ultimately, breaking beams is a disciplined verification process that ensures project quality, compliance with specifications, and reliability of the finished work.
