What does dynamic modulus of elasticity measure in concrete?

Dynamic modulus of elasticity measures the stiffness of concrete under dynamic loads, which are loads that change with time or vary in magnitude. This property is critical because it reflects how concrete behaves when subjected to forces such as vibrations, impacts, or other fluctuating stresses.

The dynamic modulus is determined using techniques that involve applying a small, fast-moving load and measuring the resultant deformation. This helps in understanding how well the concrete can maintain its shape under rapid loading conditions, which is crucial in applications where concrete structures might experience such forces.

Other options, while related to concrete properties, do not accurately describe what dynamic modulus of elasticity assesses. For instance, density pertains to the mass per unit volume of concrete, toughness relates to the energy absorbed before failure, and compressive strength refers to the maximum load-bearing capacity of the concrete material under compression. Thus, recognizing that dynamic modulus directly correlates with the behavior of concrete under changing tensions characterizes its unique role in evaluating concrete performance.