Zabiyaka O. The mechanism of cracking in slabs on a roadbed without ballast and supports of railway bridge and increasing of their crack stability

Object - concrete, reinforced concrete, mortar and rubble masonry, of which the plates ballastless bridge floor (BMP) is built and the supports are metal railway bridges, electricon operated on direct current sections of Railways; the goal is to establish a mechanism of cracking in slabs ballastless canvases and supports of railway bridges and improvement of their crack resistance; methods of research of influence of mechanical loads and electric potentials and excess charges on the crack formation in the BMP plates and bridges made the supports using the methods: measurements of electric potentials on the railway track and structures; field surveys, questionnaire survey and involved specialists; calculation and laboratory experiment to study the stress-strain state of BMP plates and bridge bearings. For laboratory studies of the joint effect of mechanical stress and excess of electric charges on the strength of concrete in tension, in conditions close to operational, has developed an original technique which consists in determining the bending strength of the samples-beams, between the upper and lower faces subjected to a potential difference; novelty - for the first time the effect of excess electrical charge on the strength of concrete and crack formation in structures; further development of the idea of destructive factors on the plate ballastless blade and abutment of the railway bridge; results - for the first time developed a classification of injuries of the BMP plates with their division into categories according to the influence on the durability, load capacity and traffic safety of trains and measures for their prevention and elimination; scope - developed recommendations to ensure trditional plates BMP (CPU-0224), and the protection of BMP plates and bridge bearings against the destructive effects of electrical potential and excess charge from leakage currents from the rails and electric fields and charges location of anthropogenic and natural origin; in the educational process.