Fig. 6 shows a comparison between the predicted values for flexural strength based upon known compressive strength using Eq. (10) as reported by Alengaram et al. [46] for OPS concretes with
compressive strength ranging from 15 to 37 MPa; Eq. (11) as reported by Lo et al. [37] for expanded clay lightweight aggregate concrete with cube compressive strength ranging from 29 to
43 MPa; Eq. (12) [4] was suggested for lightweight concrete made with expanded shale and clay aggregates with a cube compressive strength ranging from 20 to 60 MPa; and Eq. (13) [52] was suggested for lightweight concrete made with Tuff lightweight aggregate.