What is the general tensile strength of concrete pavement?

Refractory mud orCeramic materialsThe ultimate stress when it is damaged by a bending load. It is expressed as the ratio of the bending moment of failure (N·m) to the cross-sectional resistance moment (cubic centimeters) at the break, and the unit is Pa.

Flexural strength FCF = FL (BHH).

Test f--flexural strength (MPa);

f-- Failure load when subjected to flexural resistance (n);

l--The distance between two fulcrums (mm);

b--Specimen cross-sectional width (mm);

h--Specimen cross-sectional height (mm);

Only when the cross-section occurs between two loading points can the flexural strength be calculated, otherwise the result of the specimen is invalid.

Material requirements. The materials used as cement concrete surface courses include ordinary concrete, reinforced concrete.

Continuously reinforced concrete, steel fiber reinforced concrete, RCC, etc.

To prepare concrete for pavement, it is necessary to use soft 425 or 525 ordinary Portland cement.

Medium sand or coarse sand and graded gravel (gravel) stone. 28-day ultimate compressive strength of concrete.

Not less than 30 40 MPa, the ultimate flexural tensile strength is not less than MPa, and the amount of cement per cubic meter of concrete is 300 350 kg. For the lower material of double-layer concrete pavement, the requirements can be appropriately reduced.

In order to improve the performance of concrete, a small amount of early strength agent, aerated agent and plasticizer can be added.

Admixtures such as superplasticizers or polymers (see Concrete Admixtures.

The caulking material poured on the upper part of the joint is commonly used asphalt, mineral powder, asbestos chips, cork chips or rubber powder, and asphalt cement (also known as asphalt male) made according to appropriate proportions. Neoprene is also used.

Hollow tape, plastic inserts or PVC cement are used as caulking materials, and the effect is better.

The flexural tensile strength of the surface cement concrete shall not be lower, and the expressway, trunk road, heavy traffic, etc. shall not be lower. According to the Code for the Design of Urban Road Engineering CJJ 37-2012If you look at the specifics, you can look at the specifications.

Summary. The flexural tensile strength of concrete is 5MPa, which is equivalent to that of concrete with a grade of C40, and the closest strength of this coagulation degree is between, which is not easy to form.

The flexural tensile strength of concrete is the flexural strength, and the strength standard of cement concrete pavement is controlled by the flexural tensile strength. The flexural strength of the concrete should be C40 concrete.

What grade of concrete is the flexural tensile strength of 5MPa equivalent to?

The flexural tensile strength of concrete is 5MPa, which is equivalent to that of concrete with a grade of C40, and the closest strength of this coagulation degree is between, which is not easy to form. The flexural tensile strength of concrete is the flexural strength, and the strength standard of cement concrete pavement is controlled by the flexural tensile strength. The flexural strength of the concrete should be C40 concrete.

528161192,97 is equal to how many square meters.

The conversion formula of square area is: 1 square kilometer = 1,000,000 square meters, 1 square meter = 100 square decimeters = 10,000 square centimeters, 60 square abbots = 1 mu, 1 square kilometer = 100 hectares.

The standard value of flexural tensile strength of cement concrete is C30.

The cement grade is a sign of the strength of the cement, and the compressive strength of the cement grade is determined to refer to the strength of the cement mortar after 28 days of induration. For example, if the compressive strength after 28 days is 310 kg cm2, the cement is marked as 300.

Those with a compressive strength of 300-400 kg cm2 are counted as 300. There are six grades of ordinary cement.

No. 200-300 can be used for some house construction. Numbers 400 and above can be used for the construction of larger bridges or factories, as well as some important pavements and the manufacture of prefabricated components.

Labeling method. This method is to mix 1:3 cement, standard sand and specified water with cement to make soft rubber sand according to the prescribed method, and make a cube compressive test block of 7 07 x 7 07 x 7 07 cm and a figure-8 tensile test block, which are cured under standard conditions, and the compressive strength and flexural strength of 3 days and 28 days are measured respectively, and the average compressive strength of the group test block for 28 days is used to determine the cement number, but the compressive strength of 3 days and 7 days must also meet the specified requirements.

Flexural tensile strength is flexural strength, and the strength standard of cement concrete pavement is controlled by flexural tensile strength. The flexural strength of the concrete should be C35 concrete.

The flexural tensile strength of Portland concrete is greater than 5MPa in 28 days.

The 28-day flexural tensile strength of ordinary Portland concrete is also greater than 5MPa. If it is a 3-day flexural tensile strength, the corresponding mark is "=,r" indicates early strength type.

Extended information: cement concrete pavement is directly affected by the repetitive action of vehicle load and environmental factors (such as temperature and humidity), so the concrete plate is required to have high flexural strength, durability, wear resistance and slip resistance. Among them, flexural strength is an important control index of concrete pavement, and whether its size meets the design requirements will directly affect the overall quality and service life of the pavement.

Meeting these requirements depends largely on the quality of the raw materials, the composition of the mixture, and the construction control on site. Therefore, in the engineering concrete road requirements, analyze the factors that affect its strength, so as to select qualified materials, scientific design, reasonable construction, to meet the requirements of the indicators of cement concrete pavement.

Calculation formula for bending tensile strength of concrete:

ft=fl/b h2

Where: FT - flexural tensile strength pure stuffiness (MPA).

f – ultimate load (n).

l - distance between supports (mm).

b——Specimen width (mm).

h——Specimen height (mm).

h2 refers to the square of the height.

When the standard specimen (150 150 550) is used, l = 450 mm, b = 150 mm, h = 150 mm

Summary. Dear, hello, I am glad to answer for you, the flexural tensile strength of concrete pavement is generally what is the tensile strength of the pavement A: the tensile strength of pavement concrete is based on 150mm l50mm 550mm specimens, standard maintenance 28d, with the flexural strength of three points and double force points as the standard.

Dear, hello, I am glad to answer for you, the flexural tensile strength of concrete pavement is generally what is the tensile strength of the pavement A: the tensile strength of pavement concrete is based on 150mm l50mm 550mm specimens, standard maintenance 28d, with the flexural strength of three points and double force points as the standard.

The cement concrete surface layer should have sufficient strength, durability (frost resistance), and the surface should be slip-resistant, wear-resistant, and smooth. 2. The thickness is selected according to the current specifications according to the traffic grade, highway grade and variation level grade, and is determined by calculation. The flexural tensile strength of the concrete resulting from the calculation of the thickness should be greater than the superposition of the maximum load fatigue stress and the maximum temperature fatigue stress.

3. Flexural tensile strength: The flexural tensile strength of cement concrete at 28 days of age controls the strength of the surface layer concrete. The standard value of concrete flexural tensile strength required by each traffic grade shall not be lower than the following specified value (mpa): 5 0 for heavy traffic, 4 5 for heavy traffic, 4 5 for medium traffic, and 4 0 for light traffic.

The flexural tensile elastic modulus of cement concrete should be measured value. When there is no measured value, the following values can be used: when the design strength is 5 0 MPa 4 5 MPa 4 0 MPa, the flexural tensile elastic modulus is 31 000 MPa, 28 000 MPa, 27 000 MPa respectively, and the joints are provided with longitudinal and transverse joints that intersect vertically, and the concrete slab is divided into rectangular slabs to prevent cracks or warping of the plate body caused by expansion and contraction.

Longitudinal joints: set according to the width of the pavement and the width of the construction pavement. When the width of the pavement is less than the width of the pavement at one time, the longitudinal construction joint in the form of a flat joint with a tie rod should be arranged.

When the width of the paving is greater than 4 5 m, the longitudinal shrinkage joint in the form of a false joint with a tie rod should be arranged, and the longitudinal joint should be parallel to the center line of the line. Transverse joints: Transverse construction joints should be selected as far as possible at shrinkage joints or expansion joints.

The former adopts the flat seam form with a force transmission rod, and the latter is in the same expansion seam form. In special cases, the tongue and groove seam form with tie rod is adopted. Expansion joint setting is divided according to the construction season:

Except for the slabs constructed in summer, and the slabs constructed in other seasons are provided with expansion joints when the plate thickness is greater than or equal to 200 mm, and the spacing between the expansion joints is generally 100 200 m; Expansion joints are generally also set at the junction between the edge of the concrete slab and other structures adjacent to the bridge or where the thickness of the slab changes or there is a vertical curve. The transverse shrinkage joint is a false seam, which can be arranged at equal or variable spacing, and there is generally no force transmission rod. For the concrete pavement of extra heavy and heavy traffic grades, force transmission rods are provided for transverse expansion joints and shrinkage joints.

5. The anti-slip concrete surface layer should have a large roughness, that is, it has a high anti-skid performance, so as to improve the safety of driving. The structural depth of the surface layer can be formed by notching, grooving, grooving, or brushing.

ft=fl/b h2

Where: FT - flexural tensile strength pure stuffiness (MPA).

f – ultimate load (n).

l - distance between supports (mm).

b——Specimen width (mm).

h——Specimen height (mm).

h2 refers to the square of the height.

When the standard specimen (150 150 550) is used, l = 450 mm, b = 150 mm, h = 150 mm