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 sThe 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
< / BR>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
< / BR>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.
FIELD: non-destructive monitoring of welded assemblies.
SUBSTANCE: ultrasonic waves are generated at surface of thin metal sheet welded to substrate. Speed of propagation of surface waves is correlated with impact strength of welded assembly. Device has head for irradiating waves oriented to components at specific angle of inclination and head for receiving part of waves either reflected from component o or sending back that part of waves to radiating head in form of echo-signal. Second head is oriented at angle of inclination being opposite to angle of inclination of radiating head. Second head has two active surfaces disposed in steps and at like distance from component.
EFFECT: non-destructive monitoring; non-direct estimation of impact strength.
10 cl, 5 dwg
FIELD: nondestructive testing of materials.
SUBSTANCE: method comprises exciting ultrasonic oscillations in the article to be tested with the use of the first piezoelectric converter, receiving the oscillations with the second piezoelectric converter, which is mounted at a given distance from the first one, measuring the time interval which the signals take to cover the zone without defects and the article t2, comparing the time intervals, moving the piezoelectric converters over the surface of the article, and determining the front of the defect zone from time interval t2. Upon the determining of the front of the defect zone, the piezoelectric converters are displaced until the difference between the time intervals disappears.
EFFECT: enhanced reliability of determining.
SUBSTANCE: method involves producing two control samples No 1 and No 2 from patient blood serum. Distilled water, blood serum and control samples No 1 and No 2 are placed in acoustic cells of two devices connected to computer for controlling biological fluids at constant temperature of 15 to 40°C. The temperature is lower in the first device than in the second one. Ultrasound is passed through distilled water, blood serum and control samples No 1 and No 2 with its frequency varying from 2 to 40 MHz. Propagation speed is measured in each medium, relative changes of ultrasound speed in blood serum in the first and the second device are measured at corresponding temperatures and in control samples No 1 and No 2 and compared to distilled water. Ultrasound speed frequency coefficient and ultrasound absorption frequency coefficient are determined in blood serum. The obtained data are used for determining concentration of general protein, protein fractions and lipid components in blood serum.
EFFECT: high accuracy of the method.
SUBSTANCE: device has body, calorimeter working cell, temperature sensor, sensor of time of operation of ultrasound oscillations source, mixer and calibrating heater, connected to control block. Calorimeter cell is provided with thermostatting coat. Body is provided with removable lid with node for its movement of autonomous fixing. temperature sensor, ultrasound oscillations source operation time sensor, mixer and calibrating heater are positioned on said lid. In the lid opening is made for holding ultrasound oscillations source.
EFFECT: higher speed of operation, higher efficiency.
4 cl, 4 dwg
FIELD: chemical industry; petrochemical industry; analysis of the materials by the chemical methods.
SUBSTANCE: the invention is pertaining to the field of analysis of the materials by the chemical methods (by titration, with utilization of chemical indicators), containing the organic compounds of magnesium and may be used in chemical and a petrochemical industry at exercising control over the quality of petroleum. The invention provides, that magnesium chloride from the oil test is produced by impregnation of the ash-free filter with the tested oil with its subsequent incineration up to the complete ashing. Then the ash is dissolved in 30-40 cm3 of the weak 6 Mole/dm3 solution of hydrochloric acid. The produced solution id boiled within 15-20 minutes, transferred by a spray of the distilled water into the graduated flask. Take the aliquot, in which add the distilled water and neutralize it with ammonia (dropwise) up to pH=10.0, introduce the ammoniacal buffered solution and the indicating device the chromogen black ЕТ-100 and titrate 0.025 Mole/cm3 with the B-trilonum solution till the change of the a crimson-violet color into blue- pale blue, and quantity of magnesium (in mass%), is determined by the empirical formula. The invention allows to reduce the time duration for determination of the contents of magnesium, to improve the labor conditions due to exclusion from the process of the toxic and flammable benzole without reduction of requirements on toxicity and reliability of the produced results.
EFFECT: the invention ensures reduction of the time for determination of the contents of magnesium, improvement of the labor conditions, exclusion from the process of the toxic and flammable benzole without reduction of requirements to toxicity and reliability of the produced results.
FIELD: analytical methods.
SUBSTANCE: invention is intended for use as a means of metrologically supporting measurement techniques in determination of total alkaline number of motor oils and lubricating materials. This means is represented by composition containing 75-84% liquid hydrocarbons, 0.05-6% water-soluble alkali component, and 15-20% aliphatic alcohol. Use of standard specimen allows performing reliable estimation of quality of motor oils and lubricating materials by accessible acid-base titration technique requiring no special instrumentation equipment.
EFFECT: simplified analytical procedure.
SUBSTANCE: invention relates to the field of testing petroleum derivatives, in particular to testing hygroscopicity of aviation synthetic oils, and can be utilized in institutions engaged in development and application of lubricating oils for aircraft techniques and for estimating changes in quality conditions of aviation synthetic oils from tendency of oils to water absorption under operation conditions. In a method of estimating hygroscopicity of oils from amount of absorbed water, including sampling oil, keeping sample at specified relative humidity and temperature in presence of distilled water, and then calculating amount of absorbed water using thus obtained dependence, additionally calculating content of water in initial sample (C0), specifying keeping time (t) for sample of oil at specified relative humidity and temperature, and calculating amount of absorbed water (C1) in oil sample from mathematic dependence taking into consideration experimentally found maximum water solubility constant (Cmax) and constant coefficient (ka) for particular kinds of aviation synthetic oils.
EFFECT: reduced determination time and labor expenditure for determination, increased sensitivity of method under oil operation conditions without losses in accuracy and reproducibility.
1 dwg, 3 tbl
FIELD: measurement engineering.
SUBSTANCE: method and device can be used in systems for survey, transportation and preparation of oil. Continuous and simultaneous measurement of volumetric discharge Q1 and Q2 is performed in two points standing apart along flow travel in pipeline; the measurements are carried out by means of two flowmeters. Behind the first point Q1, the local hydrodynamic disturbance is generated in flow by means of expansion of cross-section of flow. Second measurement is carried out at expanded part of flow. Availability of gas is judged from excess in setting relatively current values Q1 and Q2, which value is specified in controller to which controller the both flowmeters are connected. Device for realization of the method is made in form of insertion n the pipeline.
EFFECT: improved reliability of measurement.
2 cl, 1 dwg