MPa (megapascal)
The metric unit for concrete strength used outside the United States and in engineering literature. One megapascal is roughly 145 pounds per square inch.
What does mpa (megapascal) mean?
Because much of the world's concrete research and many product datasheets are published in metric, US practitioners encounter MPa in technical documents even when jobsite conversation stays in psi. Common international grades map recognizably onto US practice, with a 25 MPa mix sitting near a 3,600 psi mix. Converting is straightforward but rounding conventions differ, so specified grades rarely translate to round numbers.
In practice
Imported admixture and repair product datasheets often quote MPa, which is why a bond strength figure sometimes looks impossibly small at first glance.