How to quickly test the strength of concrete?

1. On-site detection with rebound hammer; 2. After the test block is removed, it is immediately sent to the boiling method to estimate the strength of 28 days; 3. After the test block is dismantled, it is sent to the standard for three days or seven days after the pressure test is estimated to be 28 days of strength, and the above methods can quickly calculate the concrete strength.

To test blocks according to concrete.

determines which assessment method is used. There are two kinds, the first is a non-statistical method, and the statistical method is evaluated by the standard: average.

1 standard deviation design strength value; Minimum 2 design.

The fastest strength test of concrete produced by reasonable mix ratio is a three-day test, the three-day test pressure value is multiplied by the pressure value equal to 7 days, and the strength value of 7 days is multiplied by the strength value equal to 28 days, that is, the final setting value.

The boiling method is the fastest, and it will be good a few hours after removing the mold.

With a portable concrete strength rebound tester.

Home decoration is more concerned about every family, before home decoration most owners will understand the materials needed for decoration in advance, and will also understand the quality of materials, for example, the most basic material for home decoration concrete, I believe we all know the role of concrete, but do not know how to calculate the strength! Next, let's introduce how to calculate the strength of concrete?

Compressive strength = failure load bearing area, under standard conditions, the concrete specimen is a cube with a side length of 15cm, and the tensile strength is small, which is very important to prevent cracks, and the factors affecting the strength of concrete are closely related to the aggregate, cement-stone strength, water-cement ratio and aggregate properties in concrete.

What are the advantages and disadvantages of concrete.

1. Advantages of concrete.

Strong plasticity, with good workability, almost at will through the design and formwork to form different forms of buildings and components; There is also a good economic type, compared with other materials, the concrete ** is lower, and the maintenance cost after the structure is completed is also lower; There is also good safety, hardened concrete has high mechanical strength, so that the structural safety is guaranteed; At the same time, it has good fire resistance and will not soften quickly and collapse at high temperatures like steel structure buildings.

2. Disadvantages of concrete.

Although concrete has a lot of advantages, but at the same time there are a lot of disadvantages, the same shortcomings can not be ignored, the tensile strength of concrete is low, is one percent of the tensile strength of steel bars, and the ductility is not high, the deformation ability is poor, it belongs to brittle materials, can only withstand a small amount of tension deformation, the self-weight of the material, high-rise, large-span buildings require materials to ensure the mechanical properties under the premise, to clear is appropriate.

Under normal circumstances, if you want to measure the strength of concrete, they will have this rebound meter, and when the time comes, it will come out with a corresponding strength value and the corresponding data.

The concrete grade is represented by the 90-day age period, and now the engineering quality inspection is based on the measured compressive strength value of 28 days, because 28 days can already reflect the strength of concrete.

The concrete elements are tested for 7-day compressive strength, and if 75% of the design strength is reached, the formwork is allowed to be removed. The specific demoulding requires the design grade reached by the first slag.

1. The span is 2m and less than 2m 50;

2. The span is greater than 2m to 8m 75;

3, beam (span of 8m and less than 8m) 75;

4. Load-bearing structure (span greater than 8m) 100

5. Cantilever beam and cantilever plate 100

Concrete, abbreviated as "concrete (tóng)": refers to the general term for engineering composite materials that are cemented into a whole by cementitious materials. The word "concrete" is usually used as a cementitious material, and sand and stone are used as aggregates;

Cement concrete, also known as ordinary concrete, is widely used in civil engineering engineering when it is mixed with water (which can contain admixtures and admixtures) in a certain proportion and is mixed to obtain cement concrete.

The test block method detects the mark-to-state intensity.

At present, the test block method is the most basic and most common method for testing the strength of concrete, and it is intuitive and economically reasonable. The test block detection of concrete strength can determine the strength grade of concrete, which is an important basis for the strength grade of concrete structures, and this method occupies a very important position in a large number of quality acceptance inspections. However, there are still some shortcomings of this method, which are manifested in the following aspects:

1) When there is a large deviation or loss of the concrete test block, it will be difficult to accurately judge the concrete structure;

2) Because there are certain differences between the test block and the concrete as a whole in terms of production, vibration, maintenance, etc., the test block can not objectively reflect the strength of the represented component in some cases;

3) If there are internal defects, honeycombs, vibration leakage and other phenomena in the concrete component, the test block will not be able to correctly reflect the overall strength of the component.

2. The core drilling method detects the strength.

The basic principle of the core drilling method is to drill a core sample in a representative concrete structure, and then perform sawing, grinding and leveling processing, and then measure its compressive strength. Generally, the concrete with a strength of more than 10MPa and an age of more than 14d can be tested by the core drilling method, but the core sample will have a certain impact on the concrete structure, so in order to ensure the performance of the concrete structure, the method can only be used with the consent of the designer. It should be noted that the size of the core sample, the number of corings, and the location must meet the specific requirements.

In addition, the core drilling method can effectively detect the local damage of concrete, and the hail can truly and reliably reflect the condition of the specimen. At the same time, through the observation and detection of core samples, we can understand and grasp the internal conditions of local concrete, such as the distribution of aggregates and the size of cracks. However, this method also has certain shortcomings, namely, high labor intensity, high detection cost, and will cause some damage to the structure.

3. Rebound method to detect strength.

The rebound method refers to a method of measuring the hardness of the concrete surface with the help of a rebound tester, so as to presume the compressive strength of concrete, and the concrete strength of the structure can be detected by the rebound tester on the basis of not destroying the structural components, so as to presume the concrete strength, the position of the reinforcement, the defects, etc. The rebound method has the characteristics of simplicity and flexibility, high detection efficiency and low cost. However, compared with the test block method and the core drilling method, its accuracy is relatively poor.

In the process of using the rebound method to determine the strength of concrete, it is necessary to use some strength measurement curves to effectively judge the strength. For some special parts of the concrete or concrete made by special molding process, it is also necessary to carry out corresponding testing through a special strength measurement curve, so as to ensure the validity of the test results. It should be noted that if the concrete is affected by external factors (fire, frostbite, chemical corrosion, etc.), resulting in a large difference between the surface and the internal quality, this method cannot be used for the strength testing of concrete.

The formula for calculating the compressive strength of concrete is P=F a, where p is the compressive strength of the standard concrete cube test block, f represents the maximum pressure of the test, and a represents the cross-sectional area of the cube test block.

The strength of concrete can be tested by mechanical tests. Here are a few common methods for testing the strength of concrete:

Compressive Strength Test (CUBE TEST): This is one of the most commonly used methods for testing the strength of concrete. In the laboratory, concrete samples are usually tested in cube-shaped test blocks.

After the test block is prepared, after a certain curing period, the test block is put into the pressure testing machine for loading, and the compressive strength of the test block is determined. The strength of concrete is usually expressed in terms of the pressure it can withstand per square centimeter (or megapascal).

Flexural test: This test method is used to evaluate the flexural strength of concrete. The bending resistance of beam-shaped concrete specimens is determined by preparing beam-shaped concrete specimens in the laboratory and applying a bending load.

Flexural strength testing is often used to evaluate the performance of concrete structures under flexural action.

Tensile test: Although the tensile strength of concrete is relatively low, there are some special cases where a tensile strength test is required. This test method involves the preparation of cylindrical or beam-shaped positive potato specimens and the application of tensile loads in the laboratory to determine the tensile strength of the concrete seepage in the concrete hall.

Non-destructive testing (NDT): In addition to traditional laboratory tests, non-destructive testing methods can also be used to evaluate the strength of concrete. These methods include ultrasonic testing, rebound testers, electromagnetic wave testing, etc., which detect and analyze the physical properties of concrete, and infer the strength of concrete by clearing the ridge.

The on-site testing methods for the strength of concrete structures can be divided into non-damaged or deliberate and local damage methods.

1. Non-breakage method.

1.Rebound method.

The rebound method is a method to estimate the compressive strength of concrete based on the correlation between its rebound value, carbonization depth and compressive strength.

2.Ultrasonic rebound synthesis method.

The ultrasonic rebound comprehensive method is a method based on the correlation between the ultrasonic propagation velocity and rebound value and the compressive strength of concrete, and comprehensively reflects the compressive strength of concrete with the sound velocity and rebound value.

2. Partial damage method.

1.Core drilling method.

The core drilling method is a method that uses a special drilling rig to drill a core sample from the structure and infer the strength of the structural concrete according to the compressive strength of the core sample.

2.Pull out method.

The pull-out method is a local damage detection method, the test is to pre-embed an anchor made of metal into the unhardened concrete pouring component, or drill into the concrete component of the hardened concrete and bury an anchor, and then according to the tensile force when the anchor is pulled out, to calculate the compressive strength of the concrete.

3.Shear pressing method.

The shear compression method is to use a special extrusion jack to apply pressure to the edge of the concrete component, so that the edge of the component produces local shear compression failure, and the concrete strength of the component is inferred according to the size of its local bearing pressure, and the local failure surface after detection is smaller, which does not affect the bearing capacity of the sage base component itself.

Summary. 1. Rebound method, take the rebound hammer to detect the outer layer of the concrete structure, and analyze the data after taking the rebound value and obtain its actual strength. 2. Ultrasonic method, using ultrasonic detector to test the strength of concrete structure, it can be used to detect the strength of concrete, and can also be used to find internal defects.

3. Core sampling method, take rhinestones to drill samples of specified size on concrete components, and then take the samples to the laboratory for testing.

Kiss has three methods.

1. Rebound method, take the rebound hammer to detect the outer layer of the concrete structure, and analyze the data after taking the rebound value and obtain the actual strength of the orange bout. 2. Ultrasonic hunger method, using ultrasonic detector to test the strength of concrete structure, it can be used to detect the strength of concrete, and can also be used to find internal defects. 3. Core sampling method, take rhinestones on concrete components to drill samples of the specified size, and then take the samples to the laboratory for testing.

This is too professional, there is no local method, and it can be detected without the help of instruments.

Kissing can be done using the test block method.

It is the construction of the tomb to pour the mixed concrete into the prescribed cube test mold, after vibration or insertion, according to the temperature and humidity of the prescribed Hehe spike for 28 days after curing, the compression strength test.

The 150mm cube specimen is used as the standard part, and the 100mm and 200mm cube specimens are converted according to the specified size conversion factor.

To a certain extent, the concrete test block reflects the gross strength of the concrete entity, and is also the main basis for concrete quality assessment, which is the most common and basic detection method of rock rock skin, and is also the most intuitive and economical method.