The compressive strength of NFSMRs must be determined in accordance with the principles of BS 1924-2 Section 7.3. Curing must be in accordance with BS 1924-2 section 7.2.4. Specifically, cores must be sealed or immersed in water at 20°C or 40°C (depending on the type of binder used) for 28 days. Alternative sample manufacture techniques (including the use of cylinders or recovered cores of hardened specimens) may be adopted if they demonstrate equivalence to the above procedure.
NFSMRs may require compaction to ensure adequate strength. The compaction regime (i.e. details of plant type, weight category, lift/layer thickness and number of passes) must be specified before an NFSMR is used, and it should be determined by development and testing.