PSI - Issue 72

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

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5. Bridge maintanence strategy 9 years have passed since the reconstruction and conservation works were completed, and during that time there has been a sharp increase in biodeterioration and biodegeneration on the structural parts of the bridge, especially the foundations and arch pillars, including the terrain in the bridge area. The main causes of the accelerated development of biodeterioration and biodegradation are sudden climate changes and the presence of algae, mosses and lichens in the Drina River bed. Therefore, it is urgently necessary to develop an effective maintenance strategy in order to reduce the impact of biodeterioration and biodegradation, and thus extend Service Life and Durability of the bridge and its parts. Savings in basic maintenance, which is predominantly corrective, can be achieved by applying preventive maintenance, with the main activity being the seasonal removal of algae, mosses and lichens, as well as vegetation from the joints. 5.1 Bridge inspections Inspections of bridges are associated with registering changes and defects and at defined time intervals, determining the cause, extent of deterioration and seriousness of structural or material problems, which may affect the bearing capacity or Service Life and Durability of the bridge structure. 5.2 Monitoring Before carrying out bridge repair work, it is necessary to carry out tests and assessments of the cause, extent and rate of deterioration. Tests and monitoring of the condition of the structure include locating and identifying defects, as well as assessing the need for repair or maintenance. 5.3 Measures against biodeterioration Development of a maintenance strategy should include guidelines for design and reconstruction, maintenance, repairs and cleaning so that structures are resistant and respond successfully to the action of biodeterioration mechanisms. Preventive techniques for material degradation depend on the type of microbe present, the type of environment and the degree of damage. Taking measures against biodeterioration is limited by the fact that the bridge is of historical importance, and is under UNESCO protection, which requires special conditions and attention when applying cleaning methods for surfaces affected by biodeterioration. Nasrasadani and Sudoi (2010) proposed measures to reduce damage caused by microorganisms: establishing an effective inspection or monitoring regime to detect the occurrence of biofilm; determining the organisms that make up the biofilm (density and location); developing an integrated planning to combat microorganisms; monitoring the integrated plan and its results. 5.4 Program Investigation and testing program should include:  visual inspection;  identification (determining the degree of representation, species, floristic list, herbarium, etc.);  mapping biodeterioration;  sampling;  laboratory tests (chemical and microbiological);  sample analysis (taxonomic analysis, phytogeographical analysis,  ecological analysis,  atomic absorption,  spectrometric emission,  Fourier transform infrared spectrometry,  X-ray diffraction, scanning with an electron microscope, energy dispersive spectroscopy, etc.;  Study development with proposed measures.