How to calculate the C30 concrete demoulding time

It is calculated according to whether it is in a state of force in the design structure. It takes 28 days to dismantle under force, and it is basically 14 days to dismantle without force.

Concrete, abbreviated as "concrete (tóng)": refers to a material made of cementitious material.

A general term for engineering composite materials that cement aggregates into a whole. The word concrete usually refers to the use of cement as cementitious material, sand and stone as aggregate; 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.

Concrete can also be pressed for compressive strength.

It is divided into: low-strength concrete (compressive strength less than 30MPa), medium-strength concrete (compressive strength 30-60MPa) and high-strength concrete (compressive strength greater than or equal to 60MPa); According to the amount of cement per cubic meter, it can be divided into: poor concrete (cement consumption does not exceed 170kg) and rich concrete (cement consumption is not less than 230kg).

C30 concrete is the ordinary grade of concrete, the use is very large, the specific number is good, is based on the design, C30 concrete in the middle and lower part of the bridge is multi-purpose, the building is also very useful, the support role is more, concrete C50 (inclusive) or more basically belongs to the high grade concrete. Different structures have different requirements for concrete labeling, which is determined according to the need.

C30 concrete is generally used for frame structures, and most of them have more foundations.

For the demoulding time, it depends on whether it is under force or not in the design structure. It takes 28 days to dismantle under force, and it is basically 14 days to dismantle without force.

If used for a bed die. If the span of the slab is less than 2m, it should reach 50% of the design strength. 2-8m, 75% of the design strength. More than 8 meters reach 100% of the design strength.

The components of beams, arches and shells should reach 75% of the design strength within 8m. More than 8m should be demolished to achieve 100% of the design strength.

If it is used as a cantilever structure, it must reach 100% of the design strength regardless of the length before the mold can be removed.

It usually takes 20 days.

Reinforced concrete slabs, slabs made of reinforced concrete materials, are the basic structures or components in housing construction and various engineering structures, often used as roofs, floors, platforms, walls, retaining walls, foundations, floors, pavements, pools, etc., with a wide range of applications. Reinforced concrete slabs are divided into square slabs, round slabs and special-shaped slabs according to the plane shape. According to the force mode of the structure, it is divided into one-way plate and two-way plate.

The most common are one-way plates, four-sided two-way plates, and beamless slabs supported by columns. The thickness of the plate should meet the requirements of strength and stiffness.

There are two types of one-way slabs: cast-in-place and prefabricated. The cast-in-place slab is usually connected with the reinforced concrete beam as a whole and forms a multi-span continuous structural form. Prefabricated slabs are widely used as roofs and floors in industrial and civil buildings, and the commonly used prefabricated slabs are solid slabs, hollow slabs and trough slabs, the width of which depends on the specific conditions of local manufacturing, hoisting and transportation equipment.

In order to maintain the integrity of the prefabricated slab structure, attention should be paid to the joint construction of slabs and slabs, slabs and walls and beams (see Connection of Reinforced Concrete Structures). The calculation of a unidirectional slab is the same as that of a beam, and is calculated in terms of the thickness of the slab corresponding to the height of the beam and the width of the slab corresponding to the width of the beam in one unit of length (see Reinforced Concrete Beams).

The reinforcement of a one-way plate consists of stressed reinforcement and distributed reinforcement. The stressed reinforcement is determined by the calculation and is arranged in the tension zone below or above the slab in the span direction according to the change in the bending moment diagram. The distributed reinforcement is perpendicular to the stressed reinforcement and evenly arranged on the inner side of the stressed reinforcement, so as to fix the position of the stressed reinforcement, resist the stress generated by concrete shrinkage and temperature change when pouring concrete, and bear and distribute the stress generated by the local load on the slab.

When the span and load are large, the stressed ribs in the plate can be prestressed steel bars or steel wires.

Depending on the temperature, if it is about 20 degrees, it can be removed in 14 days, that is to say, the strength reaches 80% of the design strength, and if the span is large, it is best to remove the mold after 28 days. There should be a sequence of demoulding, generally the first branch and then the dismantling, and the first dismantling of the rear branch.

When the strength of the decompression and demoulding test block reaches 100%, the mold can be removed.

C30 concrete to reach 80%, at least about 20 days, the demoulding time is different: the beam demoulding time is more than 10 days, and the plate can be disassembled in 7 days.

Rebar refers to steel for reinforced concrete and prestressed reinforced concrete, which has a circular cross-section and sometimes a square with rounded corners. Including round steel bars, ribbed steel bars, and torsion steel bars. The steel bar for reinforced concrete refers to the straight bar or wire strip steel used for reinforced concrete reinforcement, and its shape is divided into two types: light round steel bar and deformed steel bar, and the delivery state is straight bar and disc round.

Summary. C30 concrete can be removed in 15 days under the condition of 20 degrees; If the temperature is cold, you can extend the time of mold removal, about 20 to 30 days before removing the mold; In the case of room temperature, 20 days of mold removal is better; If you are really in a hurry to remove the mold, it should not be less than 15 days.

C30 concrete can be removed in 15 days under the condition of 20 degrees; If the temperature is cold, you can extend the time of mold removal, about 20 to 30 days before removing the mold; In the case of room temperature, 20 days of mold removal is better; If you are really in a hurry to remove the mold, it should not be less than 15 days.

The carpenters were in a hurry to work, and the C30 concrete was beaten on May 25, and the temperature was more than 30 degrees.

The mold can be removed in a few days.

At least 10 days or more.

For specific products, you can consult Beijing Zhongzhen Building Research Institute. Beijing Zhongzhen Building Research Institute is a professional R&D, production, sales and consulting organization of energy dissipation and shock absorption products with independent legal personality. Since its establishment, Beijing Zhongzheng has always focused on the field of building energy dissipation and shock absorption.

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

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.

<> pro

We are glad to answer for you: C30 concrete beams can be removed in about 15-20 days. Generally speaking, C30 concrete can be dismantled in about 15-20 days under the condition of 20 degrees.

However, if the temperature is relatively low, it is necessary to extend the demoulding time, about 20 days to 30 days, to ensure that the strength reaches the standard before the demoulding concrete tells the liquid soil that the demoulder removal time has clear requirements: the column and beam of the formwork can be removed within 24 hours after pouring the excitation, the bottom mold of the beam should wait for the concrete design strength to reach 85%, (but also according to the inspection of the demoulding test block report qualified) can be removed, if the large span or cantilever beam plate, Whether it is C25C30 or higher grade concrete, it must wait until the concrete strength reaches 100%, that is, 28 days before it can be dismantled (there is still a qualified report of the demoulding test block).

<> proHello, happy to answer your <>

After the pouring of the C35 concrete column is completed, the mold can be removed one week after the pouring of the concrete is empty, and the mold can be removed when the strength reaches 70%. 2. It takes about seven days to burn, and the strength can reach 70%. After 28 days, the strength of the wheel can reach 100%.

3. Concrete pouring: refers to the process of pouring concrete into the mold until plasticization. 4. Operating conditions:

The formwork, steel bars, embedded iron parts and pipelines of the pouring concrete layer have all been installed, passed the inspection, met the design requirements, and completed the concealment and pre-inspection procedures. The shelves and walkways for pouring concrete have been erected and passed the inspection. , cement, sand, stone and admixtures have been inspected to meet the requirements of the relevant standards, and the test has issued a concrete mix notice.

The electronic gauge is accurate and flexible after inspection, and the vibrator (rod) is inspected and tested to operate normally. Hope mine can help you <>

Do you have any other questions?

How many days can the concrete of C30 mixed pants reed shed be disassembled: Generally speaking, C30 concrete can be removed in about 15-20 days under the condition of 20 degrees. However, if the temperature is relatively low, it is necessary to extend the mold removal time, about 20 days to 30 days, to ensure that the strength reaches the standard before the mold can be removed.

If the construction is under normal temperature, such as about 20 degrees, the mold can be removed in about 15 days. However, if the construction is carried out in cold weather, the removal time needs to be extended, about 30 days to dismantle. Because the concrete will set slowly in a low temperature environment, the demoulding time will also be extended.

When the concrete is dismantled, it should also be noted that for the formwork of the non-load-bearing side, if the concrete strength is not enough to ensure its edges and corners, the formwork can not be disassembled, otherwise it will affect its use effect. For other parts, if it is dismantled in a hurry, the time cannot be less than fifteen days.