The method of monitoring the strength of concrete

 

(57) Abstract:

The invention relates to the field control of concrete strength. The method includes the destruction of concrete structures and determination of concrete strength on the calibration dependence of the parameters of destruction. What's new is that when the local destruction of concrete structures record the parameters of acoustic emission signals N equal intervals of time tidetermine the volume of damaged material V and calculate the speed parameter fracture volume of concrete S = V/tiand strength of concrete determined by calibration of the relationship between concrete strength and the parameters N and S. the Technical result of the invention consists in reducing the complexity and improving the accuracy of determination of strength of concrete. table 1.

The invention relates to the field of non-destructive testing of durability of concrete structures.

There is a method of nondestructive testing of concrete strength /1/ based on the correlation between the surface strength of concrete structures and indirect strength parameters (the value of the rebound striker from the surface of the concrete, the size of the imprint on the concrete setting of the shock pulse, and so on).

Nedow. In addition, with the composition of the concrete, curing of the structure, the timing of the tests, the existing calibration dependence must be specified.

Closest to the claimed is the method of control /2/ including a definition of effort digging anchors from concrete and defining force of a pulling strength of concrete (method of separation of chipping).

The disadvantage of this method is the restriction on its use in high-density reinforcement and thin-walled structures, the strength of concrete deep layers is determined by the depth of the anchor device and the considerable complexity of the measurement.

An object of the invention is to reduce the complexity and improve the accuracy of determination of strength of concrete.

The technical problem is solved in such a way that in the method of monitoring the strength of the concrete, including the destruction of concrete structures and determination of concrete strength on the calibration dependence of the parameters of the destruction, according to the invention when the local destruction of concrete structures record the parameters of acoustic emission signals N equal intervals of time tidetermine the amount of rasmusen is given by grawerowanie relationship between concrete strength and the parameters N and s

The inventive method of monitoring the durability of concrete structures is different from the known fact that in the process of local fracture of concrete at regular intervals of time tirecords parameters of acoustic emission signals N, determine the volume of damaged material V, and calculate the speed parameter fracture volume of concrete S = V/tithen on grawerowanie relationship between concrete strength and the parameters S and N is judged on the strength of concrete.

This method can improve the accuracy and to extend the scope through the use of acoustic emission method, informative parameters of signals which are closely associated with structural changes occurring in concrete structures at the local destruction.

The claimed method allows to reduce the complexity of testing for the expense of processing operations on the tear-out anchors from concrete.

The increase in the depth of drilling allows you to control the strength of the deep layers of concrete in structures. The proposed method will also allow you to control the strength of concrete in high-density reinforcement structures. In this case, the diameter of the drill determines the allowable distance between stezza, made of concrete three compositions. The composition of the concrete was chosen to design the age class of concrete the compressive strength of the samples was B20, B30, B. Samples were made in the form of prisms size HH see research Methodology consisted of the following: concrete sample volcanopele compound was attached surface of the waveguide. The waveguide was mounted sensor acoustic emission. In accordance with the instruction manual was prepared for the measurement of acoustic emission device AF-15. In the concrete sample electrophoretogram was swirlies hole with a diameter of 24 mm During drilling were recorded count rate of acoustic emission N equal intervals of time t=1 sec. Typically, the depth of drilling holes in the sample was 50-80 mm After this was determined, the volume of damaged material. The concrete strength of the sample was determined by the method of separation of chipping (GOST 22690-88).

Processing of results of measurements included the determination of the average count rate of acoustic emission

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compute S= V/t where V is the volume of the destroyed concrete, cm3; t is the total time drilling holes in the sample C. were tested 14 samples. Resula model, built between concrete strength R and the parameters N and S

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The correlation coefficient for this model is R=0.999.

Thus, the use of this method to control the strength of concrete structures allows with minimal errors to determine the strength of concrete.

Sources of information

1. GOST 22690-88. Concretes. Determination of strength of mechanical methods of nondestructive testing. - M.: Publishing house of standards, 1999, S. 8-9.

2. Same, S. 10 (prototype).

The method of monitoring the strength of the concrete, including the destruction of concrete structures and determination of concrete strength on the calibration dependence of the parameters of fracture, characterized in that when the local destruction of concrete structures record the parameters of acoustic emission signals N equal intervals of time tidetermine the volume of damaged material and calculate the speed parameter fracture volume of concrete S = V/tiand strength of concrete determined by calibration of the relationship between concrete strength and the parameters N and S.

 

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