PSI - Issue 72

Vera Vujović / Procedia Structural Integrity 72 (2025) 5 – 12

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Table 3.Mechanical properties of materials fill filling E (Mpa) Ɛ ɤ (kg/m3) Bardet/gravel 150-300 0,30 Tufa (sedra) 15000 2000 Kedzi/gravel 1400-2100 adopted 7500 0,30 1800

The characteristics of the wood used for the grill of the bridge foundation are summarized in the Table 2. The samples were collected from the mortar used on the bridge and were subjected to tests. Based on the tests carried out, the average strength of the mortar samples for pressure was found to be 6.43 MPa and their density is 1358 kg / m 3 . 4. Biodeterioration The problem of biodeterioration significantly affects the durability of historical bridges and requires an appropriate solution by biochemists and microbiologists, including a complex analysis of the flora represented on concrete surfaces. The process of biodeterioration takes place in two phases: initiation and secondary (developmental). Moss, algae and other plant species can cause biodegeneration and biodeterioration. Biodegeneration means physical damage to the concrete parts of the bridge under the influence of plant roots and trees. The problem of biodeterioration significantly affects the durability of historical bridges and requires an appropriate solution by biochemists and microbiologists, including a complex analysis of the flora represented on concrete surfaces. Biodeterioration is generally defined as: "any undesirable change in material properties caused by the action of living organisms" (Hueck, 1968).

Fig. 4. (a); (b) and (c); Biodegradation and (d) and (e) Biodeterioration

Fig. 5. (a); (b); (c) and (d) Biodeterioration