The quality of construction products is one of the main factors affecting the efficiency and profitability of the completed construction project, ensuring its reliability and durability.
In a generalized form, the quality of the object is determined by the quality of the project, building materials and products, as well as the quality of the production of construction and installation works.
The quality of construction and assembly work is regulated by the SNiP (Part 3), which establishes the composition and procedure for the control, the execution of hidden works, the rules for the final acceptance of the finished object, etc.
Hidden works are works that, after performing other subsequent works, become inaccessible for visual assessment (preparation of foundations for foundations, waterproofing of walls, reinforcement of monolithic structures, embedded parts, etc.). Hidden works are drawn up by acts signed by the manufacturer and the representative of the technical supervision. For registration of acts for complex and responsible work, special commissions are created.
Tolerances (allowable) - possible deviations in the dimensions of parts, structures, premises, etc. They are listed in the SNiP and technical conditions. Retreats from them - marriage. The duty of a foreman and a representative of technical supervision to monitor the quality of construction and installation works. The representative of the technical supervision has the right to force a remake of poorly performed work.
Defect (according to GOST 16504) - each individual non-compliance of products with the established requirements.
An obvious defect (according to GOST 16504) is a defect, for the detection of which in the regulatory documentation required for this type of control, appropriate methods, rules, means are provided.
A latent defect (according to GOST 16504) is a defect, for the detection of which in the regulatory documentation that is obligatory for this type of control, the corresponding methods, rules, and means are not provided.
A critical defect (according to GOST 16504) is a defect, in the presence of which the use of products for their intended purpose is almost impossible or unacceptable.
A significant defect (according to GOST 16504) is a defect that significantly affects the use of products for the intended purpose and (or) its durability, but is not critical.
A minor defect (according to GOST 16504) is a defect that does not significantly affect the use of the product and its durability.
A removable defect (according to GOST 16504) is a defect, the elimination of which is technically possible and economically feasible.
Fatal defect (according to GOST 16504) - a defect, the elimination of which is technically impossible or economically impractical.
Defects during work may have a different cause. Due to the poorly performed embedment of the joints of wall panels, an unattractive appearance of the facade is created and the temperature and humidity conditions in the rooms are disturbed. Intensive corrosion of embedded parts leads to the building in emergency condition, which entails the additional performance of complex and time-consuming repair work.
The main reasons for the poor quality of construction work may be the use of low-grade and overdue materials, deviations from the design technology (failure to comply with all layers of plaster, lack of waterproofing required by the project, etc.), the use of outdated machines and imperfect tools, lack of proper control by the ITR, etc.
Sometimes defects arise due to improperly executed breakdown of buildings and structures in the axes and height, poor compaction of soil in embankments and excavations, improper installation of reinforcement (including with a reduced section) when performing reinforced concrete work, improper and poor-quality welding work, and t dd
Quality control work performed by visual inspection, full-scale measurement of linear dimensions, testing structures destructive and non-destructive testing methods.
A visual inspection is carried out to identify cracks, visible defects, deviations from the requirements of the project.
Non-destructive quality control is used to determine the physico-mechanical and geometric parameters of the main structural elements of the building (structure). In the process of performing work on the sites indicated in the diagnostic plan, the physicomechanical and geometric parameters of the main bearing elements of the building (structure) and the construction site are determined. All measurement points are attached to the plan and section of the building (structure) and the construction site. Apply the following types of non-destructive testing.
The pulsed acoustic method consists in measuring the velocity of propagation of elastic waves in the material under study and dissipating the energy of these waves. It is used to determine hidden defects in concrete and reinforced concrete structures, to determine the density and strength of concrete and bricks.
Pulsed vibration method based on the measurement of attenuation
natural oscillations taking into account the constructive forms of the studied
an item.
The radiation method is based on the determination of the change in the intensity of y-ray fluxes during the transmission of material. According to the readings of the counters, which determine the amount of y-ray isotopes emitted, absorbed and passed through the object under study, determine the quality and properties of materials.
Geoseismic measurements. The geo-seismic structure of the site, the determination of the physicomechanical and dynamic characteristics of the ground, as well as the state of the supporting structures of the building are determined by engineering seismic prospecting using the refractive correlation method (CMR).
Dynamic measurements. Produced to determine the dynamic and stiffness characteristics, bearing capacity of structural elements of buildings and structures, to identify hidden defects.
Geodetic measurements are used to identify the features of ensuring spatial rigidity and stability under possible loads, the mapping of defects, the determination of banks and sediment, the determination of their causes and the prediction of their possible development during operation.
Thermal imaging control for detecting hidden defects in enclosing structures, joints and interfaces of enclosing structures using the method of fixing heat fluxes, drawing up a heat and power certificate for a building (structure)
Quality assurance of construction and installation work is achieved by systematically monitoring the implementation of each production process. From the standpoint of the organization of control, it is divided into internal and external.
Internal control is a function of the administrative and technical staff of a construction organization. Operational daily monitoring is carried out in the process of construction and installation works.
External control over the implementation of the construction is carried out by state bodies and the customer. State bodies - inspections of architectural and construction supervision (IGASN) carry out comprehensive control not only over the construction process, but also over interaction with the environment (garbage collection, provision of passages, etc.).
The customer carries out technical control. Controlling functions are assigned to a special representative who oversees ensuring the quality of work, arranging duly concealed works, observing deadlines for work, and checks the volumes performed.
Designer supervision is carried out by the design organization, which controls the builders' observance of design solutions and the quality of construction and installation works.
The final commissioning of the building by the State Commission provides not only a visual assessment of the structure and all its premises, but also the availability of all necessary and completed acts of performance of work, including acts for hidden work.
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