What is the strength of C35 concrete in 20 days

It depends on the design of your mix ratio, as well as the size of the affluence coefficient and the maintenance conditions. The big one can reach 35MPa in 20 days, and the low one may be 30MPa.

It's usually around 30. The strength of concrete increases over time. We measured the intensity of C35 at 28d.

First, the strength of C35 pumping concrete for 20 days is generally combined with mixing stations in different regions, different ratios, etc., slightly different, from a personal point of view, more than 20 days of standard breeding should generally reach (.

2. A brief introduction to the strength grade of concrete:

The strength grade of concrete refers to the compressive strength of the concrete. The strength grade of concrete should be divided by the standard value of the compressive strength of the concrete cube. The symbol c is used with the standard value of the compressive strength of the cube (in n mm 2; or MPA).

The compressive strength of concrete is obtained by testing, and the cube specimen with a side length of 100mm is used as the standard size specimen of concrete compressive strength below the latest standard C60 strength. In accordance with the "Standard for Test Methods for Mechanical Properties of Ordinary Concrete" GB T50081-2002, the cube with a side length of 150mm is cured to 28 days old under the conditions of standard curing (temperature 20 2, relative humidity above 95%), and the ultimate compressive strength measured by the standard test method is called the compressive strength of the concrete standard cube, which is expressed as FCU. According to the GB50010-2010 "Code for the Design of Concrete Structures", in the overall distribution of the ultimate compressive strength of the cube, the compressive strength of the cube specimen with a strength guarantee rate of 95% is called the standard value of the compressive strength of the concrete cube (calculated in MPA), which is expressed by FCUK.

70% intensity for 7 days and 100% intensity for 28 days. If you use C40, you can reach 85% C35 strength in 7 days, and 100% C35 strength in 14 days.

C35 concrete compressive strength: 35MPa FCUK<40MPa.

The strength grade of concrete.

Refers to the compressive strength of concrete. According to the "Concrete Strength Inspection and Evaluation Standard".

GB T 50107-2010), the strength grade of concrete should be determined according to the standard value of its cubic compressive strength. The symbol c is used with the standard value of the compressive strength of the cube (in n mm 2; or MPA).

In accordance with GB50010-2010 "Code for Design of Concrete Structures".

It is stipulated that in the overall distribution of the ultimate compressive strength of the cube, the compressive strength of the cube specimen with a strength guarantee rate of 95% is called the standard value of the compressive strength of the concrete cube (in MPa), which is expressed by FCUK. Ordinary concrete is divided into fourteen grades, namely: C15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75, C80.

Affects the strength grade of concrete.

The main factors are cement grade and water-cement ratio.

aggregates, age, curing temperature and humidity, etc.

Lightweight concrete is concrete with an apparent density of less than 1950kg m. It can be divided into three categories:

1 Light aggregate concrete.

Its apparent density is 800 1950kg m, and the light aggregate includes pumice, volcanic cinder, and ceramsite.

Expanded perlite, expanded slag side rent, slag, etc.

2 Hollow concrete (foam concrete.

aerated concrete), its apparent density is 300 1000kg m. Foam concrete is made of cement slurry or cement mortar.

made with stable foam. Aerated concrete is made of cement, water and gassing agents.

3. Macroporous concrete (ordinary macroporous concrete, light aggregate macroporous concrete), there is no fine aggregate in its composition. The apparent density range of ordinary macroporous concrete is 1500 1900kg m, and it is prepared with crushed stone, soft stone and heavy slag as aggregates. The apparent density of light aggregate macroporous concrete is 500 1500kg m, which is prepared with ceramsite, pumice, broken bricks, slag, etc. as aggregates.

It can reach about 30 percent in 24 hours. This depends on the mix ratio and the raw material. For example, early strength cement, concrete slump and so on will have a direct impact.

24 hours of curing plus an estimated 48 hours of demolding.

Although there are many types of vehicles, the structure is similar. This should be said to be the credit of standardization, but also the need for large-scale production lines. With the development of society, the progress of science and technology and the change of demand, the shape of railway vehicles has begun to change, especially the passenger car is no longer the same old face.

However, their basic structure has not changed significantly, but the specific parts have a more scientific and advanced structural design.

Generally speaking, the basic structure of the vehicle is composed of five parts: the car body, the undercarriage, the running part, the coupler buffer device and the braking device.

The body is the part of the vehicle that is used to load goods or passengers, and is the basis for the installation and connection of other components of the vehicle. The body of the early vehicles was mainly made of wood, supplemented by steel plates, bow rods, etc. In modern times, the car body is mainly steel structure or light metal structure.

The strength of ordinary C30 concrete can reach about 50% under normal conditions in three days.

The quality of concrete is closely related to the type, amount and mode of admixture, and it is also one of the important factors affecting the strength of concrete. The strength of concrete can only ensure normal development under the condition that temperature and humidity are suitable, and it should be maintained in accordance with the provisions of the construction code. The temperature has a certain influence on the development of concrete strength.

In summer, it is necessary to prevent exposure to the sun, and make full use of the time when the temperature is high and low in the morning and evening to pour concrete; Minimize the transportation and pouring time, prevent exposure to the sun, and increase the collapse of the mixture when it comes out of the tank; Intermittent watering should not be done during curing, as the temperature of the concrete surface rises when it dries.

Cooled during watering, this alternating effect of hot and cold makes the concrete less strong and resistant to cracking. In winter, it is necessary to keep warm and prevent frost damage, and the comprehensive heat storage method and steaming method are generally adopted for winter construction.

Main advantages: The quality of concrete is closely related to the type of admixture, the amount of admixture, and the way of incorporation, and it is also one of the important factors affecting the strength of concrete. The strength of concrete can only ensure normal development under the condition that temperature and humidity are suitable, and it should be maintained in accordance with the provisions of the construction code. The temperature has a certain influence on the development of concrete strength.

It depends on the temperature at that time and the heat dissipation of the pouring parts. Under standard curing conditions, the strength of ordinary Portland cement can exceed 50% in 3 days (72 hours), and the strength in 2 days is 30%-40%.

1. Before the concrete strength reaches 1 2n mm2, the formwork and bracket shall not be stepped on or installed on it.

2. The above requirements are from the "Code for Acceptance of Construction Quality of Concrete Structure Engineering GB 50204".

3. In East China, you can go up to lay out the line three or four hours after the completion of the summer close, and you need to go up the next day for construction in winter; Some projects are blindly rushed, and the concrete is done without surface dryness.

Depending on the temperature, the number of days required will vary, and the specific schedule is as follows.

Reference time to reach the required strength for dismantling the concrete bottom formwork (excerpt from the Construction Manual) 425 ordinary cement is used.

Number of days required:

The concrete grade is represented by the 90-day age period, and the compressive strength is measured in 28 days for the engineering quality inspection.

The value prevails, because 28 days can already reflect the strength of the concrete. The concrete components are tested for 7 days of compressive strength, and if 75% of the design strength is reached, the formwork will be dismantled.

Summary. C30 concrete fourteen days strength to reach the standard of Hello dear, C30 concrete compressive strength in 14 days when the rebound value reaches the qualified concrete under normal conditions of carbonization depth is, if it is pumped concrete, carbonization depth, then the rebound value is qualified in the above, if it is not pumped concrete must reach the above, depending on the specific situation. It can penetrate the surface of the concrete 3-30mm, and its active ingredients can quickly react with the free calcium in the concrete to form a gel substance, thereby increasing the compactness of the structure and forming a solid entity on the concrete surface, thereby greatly improving the strength, hardness and wear resistance of the concrete surface.

Hope my answer is helpful to you, <>

C30 concrete strength in 14 days to reach the standard.

C30 concrete fourteen days strength to reach the standard of Hello dear, C30 concrete compressive strength in 14 days when the rebound value reaches the qualified concrete under normal conditions of carbonization depth is, if it is pumped concrete, carbonization depth, then the rebound value is qualified in the above, if it is not pumped concrete must reach the above, depending on the specific situation. It can penetrate the surface of the concrete 3-30mm, and its active ingredients can quickly react with the free calcium in the concrete to form a gel substance, thereby increasing the compactness of the structure and forming a solid entity on the concrete surface, thereby greatly improving the strength, hardness and wear resistance of the concrete surface. Hope my answer is helpful to you, <>

If the coring pressure test is more or less qualified.

Dear, hello, how qualified is the concrete core strength, the judgment standard is 88% of the average design strength of a group of three core samples, and the minimum compressive strength design strength of a group of core samples is 80%. At the same time, the above conditions are met and judged to be qualified.

Summary. Hello, after inquiry, the strength of concrete C30 can reach about 20MPa in 4 days at a temperature of 30 degrees.

How much strength can concrete C30 achieve in 4 days at a temperature of 30 degrees?

Hello, after inquiry, the strength of concrete C30 can reach about 20MPa in 4 days at a temperature of 30 degrees.

Generally, the strength of three days can reach about 17---20MPa, which is also related to the mix ratio of concrete, if you use early strength cement, it must be a little higher, if you add mineral admixtures, such as fly ash and slag, the strength must be a little lower.