Technical inspection of reinforced concrete structures

Abstract

With the help of non-destructive testing devices, on-site inspections of prefabricated reinforced concrete frame structures, which were in operation, were performed to establish their reliability and suitability for further use in new construction. At the same time, verification calculations of the bearing capacity of the examined structures were performed. A detailed survey of building structures was performed: columns, covering beams, and covering slabs.

Survey work was carried out by the construction research laboratory at the Department of Construction and Civil Engineering of the Lutsk National Technical University.

As a result of the technical inspection, it was established that a long period of operation of the structures, adverse environmental effects, and violations of technology during dismantling and transportation led to several damages and defects of individual structural elements, which worsened their technical condition.

When performing a technical inspection of precast concrete structures (14 columns of the 2K48-3m2 brand, according to the type of series 1.423-3 v.1 with a cross-section of 300´400 mm; 50 columns of the brand 2K60-4M2 according to the type of series 1.423-3 v.1 with a cross-section of 400´400 mm 26 columns of the 5K60-5M2 type series 1.423-3 v.1 with a section of 400´400 mm, 32 cover beams with parallel belts of the 3BSO 12-A IV series type 1.462.1-1/81, L=12000mm; 13 girder covering beams of the BDR-18-2 А IV type of series 1.462.1-1/80, L=18000mm; 196 ribbed covering slabs of the PG3 A IV brand, type series 1.465, with dimensions of 6000×3000 mm) showed chipping of concrete, minor potholes that are the result of dismantling and transportation works, partial exposure of structural reinforcement, its corrosion and corrosion of embedded parts. The condition of all structures is satisfactory - category "2". It is recommended to eliminate defects, and bring structures to a normal state - category "1", for which measures should be provided:

• mechanical separation of the exfoliated protective layer of concrete from structural and working reinforcement;
• cleaning of the corrosion layer from structural fittings, and embedded parts by mechanical and chemical methods;
• performance of anti-corrosion protection of fittings and embedded parts with Ceresit CD 30;
• restoration of the protective layer of structural reinforcement with fine-grained concrete, concrete class C ≥ 30, (for columns C ≥ 25), Ceresit CD 26, Ceresit CD 21.

When carrying out measures to eliminate defects of prefabricated reinforced concrete structures - covering slabs, columns, covering beams, these structures are suitable for use in new construction and further operation.