Fig. 23: Comparison of embodied carbon per unit compressive strength.

The embodied carbon per unit strength of each mixture was computed from Embodied carbon per unit compressive strength = Embodied carbon_i/f_c,28,i, where i denotes the i-th mixture and f_c,28,i is its 28-day compressive strength. Data for conventional concrete are sourced from ref. ³⁸⁷ via the open-source dataset published on University of California, Irvine (UCI) Machine Learning Repository³⁸⁸. The dataset was filtered to include only 28-day results with compressive strength ≥20 MPa, yielding a total of 286 entries with strength ranging of 21.9–82.6 MPa. The main constituent of the conventional concrete are PC, QS, SP, GGBFS, FA, and coarse aggregate. For UHPC, data points falling below the minimum value prescribed by international provisions^1,2 are attributed to the exclusion of fibre (i.e., UHPC matrix only), as these mixes were intentionally designed in the respective studies to serve the specific research purposes set forth therein. The annotated values in the figure represent the mean of the respective data distributions. For categories with only a single data point, no box-and-whisker plot could be generated; instead, only the mean marker is shown.