What is the range of concrete slump for C25?

Slump requirements:

1. Self-mixing concrete: C15 is 3-5mm; C20, C25, C30 is 7-9mm.

2. Commercial concrete: C15, C20, C25, and C30 are all 18 2 mm.

Influencing factors. Raw materials.

Due to the different storage time and batch, the water content of Shahe washed sand is different.

Unstable, and the limitation is greater when the water content is determined by the test, the water content of coarse aggregate is generally relatively stable, but sometimes it will change, because the aggregate plant is mostly open storage, the aggregate water content changes after rain, and the aggregate water absorption rate is different when mixing concrete, which will cause concrete slump.

varying degrees of deviation.

Stirring time. The long mixing time of concrete will cause the water absorption of aggregate to increase, so that the free moisture in the concrete clinker is less, resulting in the loss of concrete slump.

Metering system error of concrete mixing machinery.

It will also cause concrete slump loss, concrete mix ratio.

It is obtained through accurate calculation and adjustment after many trial matching, and any kind of material will make the specific surface area of the material in the unit due to inaccurate measurement.

The greater the change in the specific surface area of the material, the greater the loss of slump over time.

Transport machinery. The longer the concrete mixer truck transports the distance and time, the concrete clinker due to the chemical reaction.

Water evaporation, aggregate water absorption and other reasons, the reduction of free moisture, resulting in the loss of concrete slump over time, concrete belt conveyor, string drum will also cause mortar loss, which is also an important reason for the loss of concrete slump.

Pouring speed. In the process of concrete pouring, the longer the concrete clinker arrives in the silo surface, the free moisture in the concrete clinker will be rapidly reduced due to the occurrence of chemical reaction, water evaporation, aggregate water absorption and other reasons, resulting in slump loss, especially when the concrete is exposed to the belt conveyor, the contact area between the surface and the external environment is larger, and the water evaporates rapidly, which has the greatest impact on the concrete slump loss. According to the actual measurement, when the temperature is about 25, the slump of the concrete clinker site can reach 4cm in half an hour.

Pouring time. The different pouring time of concrete is also an important cause of concrete slump loss. The temperature is low in the morning and evening, and the water evaporates slowly, which has less impact; The temperature is high at noon and in the afternoon, and the water evaporates quickly, which has a great impact.

The faster the moisture loss, the greater the slump loss of concrete, the worse the fluidity and cohesion of concrete, and the more difficult it is to ensure the quality.

According to the mix ratio design and the characteristics of ordinary C25 concrete, the maximum value of slump will not exceed 240mm when the workability is good, and the concrete has the best working performance when the slump is between 160-220.

The concrete slump is set in the design of the concrete mix ratio, under normal circumstances, the pumped take 180 30mm, the non-pump 140 30mm, and the underwater pile 200 30mm.

The slump of general engineering is somewhat different according to the combination of relevant concrete materials and additives in the region, and is generally controlled between 120-180 plus or minus 30. There are standards, but it depends on the actual situation on the site.

The slump of concrete is generally determined according to the actual needs of the construction site. There is a standard for slump, but in practice, how to use it determines the size of slump.

Introduction

Concrete slump mainly refers to the plasticizing performance and pumpable performance of concrete, and the factors affecting concrete slump mainly include gradation changes, water content, weighing deviation of the scale, the amount of admixtures, and the temperature of cement that is easy to be ignored. Slump refers to the workability of concrete, specifically to ensure the normal progress of construction, including the water retention, fluidity and cohesion of concrete.

Workability refers to whether the concrete is easy to construct and operate, and the performance of uniform compactness, which is a very comprehensive performance, including fluidity, cohesion and water retention. The effects and workability mainly include water consumption, water-cement ratio, sand rate, including cement variety, aggregate conditions, time and temperature, admixtures and other aspects.

It depends on what you need, if it is a cushion or a flat field, the collapse is larger, 220, the general collapse of concrete is between 180 and 220, the larger the more fluidity, such as stairs and the like need a small collapse to play.

"Generally controlled between 120-180 plus or minus 30", this should not be right, the concrete slump suitable for pumping should be controlled between "100mm 230mm", preferably between "150mm 230mm".

Generally, the line foundation concrete is made of plastic concrete, and the slump is between 10-90mm. The other party will design the mix ratio according to the slump index you need.

4. General.

There is no fixed standard for slump, such as pumping, it is generally about 120-140; Underwater concrete is generally around 160-180; Non-pumping is generally around 80--120.

The slump mainly refers to the plasticizing performance and pumpable performance of concrete, and the main factors affecting the slump of concrete are gradation changes, water content, weighing deviation of the scale, the amount of admixtures and the temperature of cement that is easy to be ignored.

The slump of concrete should be determined according to the structural section of the building, the content of reinforcement, the transportation distance, the pouring method, the mode of transportation, the vibration capacity and the climate.

According to the national standard specification, the pumping should be 180 plus minus 20, and the unloading is 120 plus minus 20.

The elevation of the pouring site, the spacing of the rebar and the particle size of the concrete gravel all have an impact on the slump, and the slump cannot be explained by looking at the concrete alone.

Crushed stone concrete, cement strength grade, then C35 concrete mix ratio is, the amount of material per cubic meter: kg water: 205 cement:

466 Sand: 571 Stone: 1158 Mix ratio:

Water: Cement: 1 Sand:

Stones: Sand Rate: 33% Water-Cement Ratio:.

The collapse of C35 commercial concrete is 160 200, and the most common is about 180.

Self-mixing concrete C10 C15 is 3-5; C20 C25 C30 C35 is 7-9, commercial concrete C10 is not specified C15 C20 C25 C30 C35 is 18 2.

Slump propagation method:

When the slump is greater than 220 mm, the slump cannot accurately reflect the fluidity of the concrete, and the average diameter of the concrete after expansion is used as the fluidity index.

At the same time as the slump test, the cohesion and water retention of the concrete mixture should be observed, so as to comprehensively evaluate the workability of the concrete mixture.

The evaluation method of cohesion is as follows: gently knock on the side of the collapsed concrete cone with a tamper, if the cone gradually sinks, it means that the cohesion is good; If the cone collapses, partially cracks, or segregation, it indicates poor cohesion.

Water retention is assessed by the degree of precipitation of dilute cement slurry in the concrete mixture. After the slump cylinder is lifted, if more dilute cement slurry is precipitated from the bottom, and the aggregate is exposed due to the loss of slurry in the cone part, it indicates that the water retention performance of the concrete mixture is not good. If there is no dilute cement slurry or only a small amount of dilute cement slurry precipitates from the bottom after the slump cylinder is lifted, it means that the concrete mixture has good water retention.

According to the national standard specification, the pumping should be 180 plus minus 20, and the unloading is 120 plus minus 20.

There are design slumps and actual measured slumps. It also depends on the adaptation of the cement to the admixture and whether it is pumped. The slump of C35 is not what it should be. I guess it should be 180 plus minus 20, or, FYI.

120---150 depending on the pouring environment and process.

Summary. Hello dear to you. The standard self-mixing of C25 concrete slump is 80, and the commercial concrete is 80-120.

Generally in 180mm-200mm. In high-temperature construction, the slump of concrete should not be less than 70mm, when the concrete strength grade is less than C50, the slump should be less than 180 mm, and when the strength grade is greater than C50, the slump should be greater than 180 mm.

Hello dear to you. The concrete slump range of C25 is 180mm-200mm

Hello dear to you. The standard self-mixing of C25 concrete slump is 80, and the commercial concrete is 80-120. Generally in 180mm-200mm.

In the high-temperature application of ants, the slump of concrete should not be less than 70mm, the concrete strength grade is less than C50, the slump should be less than 180 mm, and the slump should be greater than 180 mm when the strength grade is greater than C50.

The measured values of C15, C20, C25, C30 and C35 collapse of concrete sheds are not fixed.

The collapse of concrete is between 10 mm and 160 mm, and some concrete has a greater slump than 160 mm. When performing concrete mix experiments, it is necessary to determine the collapse range of concrete.

There is no specification requirement for the slump of concrete, the concrete slump of the corresponding part will be explained in the construction drawings, and the mixing plant is proportioned according to the slump requirements of the design, generally adding fly ash and admixtures to increase the fluidity of the concrete.

The slump is high, as long as the water-cement ratio is well controlled, there will be no segregation. Generally, the concrete slump above plus or minus zero is about 150mm, and if it is an underwater cast-in-place pile, the slump will be larger, generally about 180mm-200mm.

Summary. The design of the slump mainly depends on the construction part you pour, for example, the pouring part is a plate, etc., and the slump can be controlled at 140-160mm; The pouring part is a wall, etc., and the slump can be selected at 160-180mm, and if the wall is narrow, it can also be selected at 180-200mm; If it is the ground, try to choose a small one, such as 120-140mm.

Normal concrete generally refers to the artificial stone made of cement as the main cementitious material, mixed with water, sand, and gravel, mixed with chemical admixtures and mineral admixtures if necessary, matched in appropriate proportions, and hardened by uniform stirring, dense molding and curing. Concrete is mainly divided into two stages and states: the plastic state before setting and hardening, that is, fresh concrete or concrete mixture; The hard state after hardening, i.e., hardened concrete or concrete.

At present, the strength grade of ordinary concrete in China is divided into 14 grades: C15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75 and C80.

What is the slump of C25 concrete?

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The design of the slump mainly depends on the construction part you pour, for example, the pouring part is a plate, etc., and the slump can be controlled at 140-160mm; The pouring part is a wall, etc., and the slump can be selected at 160-180mm, and if the wall is narrow, it can also be selected at 180-200mm; If it is the ground, try to choose a small one, such as 120-140mm.

Normal concrete generally refers to the artificial stone made of cement as the main cementitious material, mixed with water, sand, and gravel, mixed with chemical admixtures and mineral admixtures if necessary, matched in appropriate proportions, and hardened by uniform stirring, dense molding and curing. Concrete is mainly divided into two stages and states: the plastic state before setting and hardening, that is, fresh concrete or concrete mixture; The hard state after hardening, i.e., hardened concrete or concrete.

At present, the strength grade of ordinary concrete in China is divided into 14 grades: C15, C20, C25, C30, C35, C40, C45, C50, C55, C60, C65, C70, C75 and C80.

The size of the slump of C25 concrete cannot be determined.

Only the concrete grade is C20, and it is impossible to determine the size of the concrete collapse.

The collapse of low-plastic concrete can be in 10, 40 mm.

The collapse of plastic concrete can be 50 to 90 mm.

The collapse of fluidity concrete can be 100 to 150 mm.

The collapse of high-flow concrete can be as high as or greater than 160 mm.

This is related to the ratio, there is no exact corresponding value, set as needed.

Check the book of relevant materials, it is recorded as follows: the concrete mixture is divided into 4 grades according to the size of the slump ("Concrete Quality Control Standard" GB50164-92) low-plastic concrete, slump 10-40mm, plastic concrete, slump 50-90mm, fluidity concrete, slump 100-150mm, high-fluidity concrete, slump greater than 160mm

The slump of pumped concrete at the general construction site on our side is between 140-160mm, and it is qualified within plus or minus 20mm.