Issue 59

M. A. R. Elmahdy et alii, Frattura ed Integrità Strutturale, 59 (2022) 486-513; DOI: 10.3221/IGF-ESIS.59.32

after 56 days. Whenever the bacteria content increases from 0.25% to 2.5%, using % bacteria BM, the difference between mix M5 and mix M6 is 2.71 MPa at 28 days and 2.96 MPa at 56 days. Furthermore, using 2.5% bacteria EMCC, the distinction between mixes M7 and M8 is 1.08 MPa at 28 days and 2.1 MPa at 56 days. The increase in flexural strength is due to the bacteria-precipitated materials being involved in the hydration process, resulting in the formation of C-S-H, which is responsible for strength development [15,49].

Figure 24: Effect of bacteria concentration on mortar bending strength for specimens without pre-cracking, at 7 days, 28 days, 56 days and 90 days: (A) Using 0.25% BM, (B) Using 0.25% EMCC, (C) Using 2.5% BM and (D) Using 2.5% EMCC.

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