Dataset consists of:
1) Figure 2. Relationship between OD600 of S. pasteurii and nephelometric turbidity. The error bars are too small to be visible.

2) Figure 4. Bacterial OD600 and specific urease activity (measured right after bacterial harvesting) for MICP cycles.

3) Figure 5. Outdoor temperature in Kilsyth, North Lanarkshire, UK. Data obtained from web page (World Weather Online, 2022). Red arrow marks the start of the injection of bacterial solution for each cycle (e.g. C1 means cycle 1). Duration of each cycle was marked in blue font.

4) Figure 8. (a) Stress-strain curves of the three 10-cm cores (two cut from core run E5 and one from F1) during UCS test.

5) Figure 9 & 10. CD triaxial test results under three effective confining stress (100, 300, 500 kPa).

6) Figure 11. (a) peak strength and (b) ultimate strength at critical state of the treated specimens and untreated sand against the corresponding mean effective stress p′.

7) Figure 12. (a) CaCO3 content plotted against Vp for the eleven sub-sampled cores subjected to the triaxial test and for the three untreated sand samples (untreated); (b) zoomed-in plot with the four X-CT scanned samples labelled.

8) Figure S1. (a) Grain size distribution of the untreated construction sands used in this study.

9) Figure S2.  (a) Changes in electrical conductivity of 18 ml urea added with 2ml bacteria (OD600 = 1) for the determination of the specific urease activity. (b) Specific urease activity of bacteria at 4, 10 and 20 ℃; (c) CaCO3 precipitation after 20-hour reaction in batch experiment (temperature: 4, 10 and 20 ℃).

10) Figure S7. P-wave velocity plotted against dry density of the twenty-two sub-sampled cores. The nine sub-sampled cores subjected to triaxial CD test are labelled by blue circles, the sub-samples cores with highest and lowest Vp are labelled by red rectangular and green asterisk, respectively.

11) Figure S8. (a) peak stress ratio, (b) stress ratio at critical state, (c) secant modulus E50 (normalised by effective confining stress) plotted against CaCO3 content (>13%).