Assertion: concrete's strength | /r/HasProperty | required
Facets:
Source sentences:
text: Concretes with high supplementary cementitious materials to reach the required strength often require longer cure times than conventional concrete.
text: For example, footings and mat slabs, as well as shear walls and columns at lower levels of high-rise structures, are good targets for low cement mixes even when relatively high strengths are required.
text: Once the concrete reaches the required strength, the stretching forces are released.
text: Once the concrete has hardened to the required strength, the steel tendons are inserted and stretched against the ends of the unit and anchored off externally, placing the concrete into compression.