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Crack generation is more prominent in the summer construction of concrete with a large horizontal surface of concrete. For example, summer construction of cement concrete pavement, cement concrete bridge deck, and bridge deck pavement, etc., have appeared to varying degrees of early cracks before maintenance.

The main characteristics of summer construction of large horizontal surface concrete.

1. Hot climate, high temperature

2. Raw materials: high temperature of the constituent materials of concrete due to high temperatures, sun exposure, used to form a concretemixture of sand, stone materials with high temperature; new factory cement, often high temperature, due to the hot climate, the heat in the cement is not easy to disseminate, coupled with the impact of the sun and other factors, making the temperature of the cement is high, the temperature of certain cement can be as high as 70 ℃.

3.High temperature of the concrete foundation or formwork and other supports

4.Large exposed surface and great influence by environment

5.Variable climate

The main reasons for cracks on the surface of the concrete

1.The surface water evaporation rate is large, resulting in water loss on the surface of freshly poured concrete. The formation of plastic and shrinkage cracks on the surface of the concrete loss of water and plastic shrinkage is the main reason for cracks.

When the evaporation rate of the concrete surface is more than 1kg/m2/h, its surface is prone to plastic contraction cracks. Air temperature, concrete mix temperature, relative humidity, and wind speed are the main factors affecting water evaporation from the concrete surface. The higher the temperature of the concrete itself, the smaller the relative humidity of the air, and the higher the wind speed, the greater the rate of water evaporation from the surface of the concrete. In summer, due to the higher temperature, the heat of hydration of the cement in the concrete is produced in a shorter period, which promotes the elevation of the temperature of the concrete in the early stage.

Relevant data show that when the temperature is 14 ℃, the first 24h after mixing concrete produces 43% of all the heat of hydration; when the temperature is 30 ℃, the first 24h after mixing concrete produces 62.5% of all the heat of hydration.

The high temperature of coarse and fine aggregates and cement itself, on the one hand, increases the temperature of early concrete. On the other hand, it concentrates the heat of cement's hydration. The high temperature of the environment makes the heat in the concrete not easy to disseminate. Thus the overall temperature of the concrete is much higher than that of concrete constructed in other seasons.

Under the influence of dry wind in summer, the high-temperature concrete increases the evaporation rate of water on the surface, leading to rapid water loss and serious plastic shrinkage. At the same time, the high temperature inside promotes the rapid hydration of cement and hardening of concrete. The combined effect of severe plastic shrinkage on the surface and internal constraints caused plastic shrinkage cracks on the concrete surface.

Water evaporation not only caused surface cracks. And water loss makes the concrete surface cement hydration water insufficient, affecting the surface concrete hardening and strength growth.

2. Concrete section temperature difference makes the surface thermal cracks

Concrete in summer construction, due to the foundation or formwork by the sun and other effects, the temperature is higher than the ambient air temperature. Its height makes the hydration rate of cement in concrete with its adjacent parts. The rate of hydration heat generation is greater than the surface, increasing the temperature difference between the surface and the internal concrete. When the difference between the surface and internal temperatures is more than 15 ℃, it is easy to produce surface thermal cracks.

Foundation or formwork by the influence of high-temperature concrete, but also easy to produce expansion deformation, and large surface concrete thickness is generally small, the lower part of the expansion deformation on the surface of the concrete contraction to produce reverse constraints, so that the tensile stress sentence increases, the surface cracks caused by the adverse effects.

3. The high temperature on the concrete microstructure produces unfavorable effects

It is generally believed that the base microstructure change is negligible when the concrete temperature is below 50 ℃. When the concrete temperature exceeds 70 ℃, its microstructural changes are unfavorable. The impact of high temperature of mass concrete is often ignored.

In the summer construction of general concrete structures, due to air temperature, material temperature, formwork or foundation temperature, and the impact of the concentrated release of the heat of hydration of cement, resulting in the temperature rise will often make its temperature exceeds the maximum temperature of the unfavorable, due to the early age of the concrete resistance to deformation capacity is small, the concrete microstructural changes not only affect the overall strength of the concrete but also prone to the formation of thermal cracks on the surface.

4. The climate is variable so that the concrete surface is easy to be hit by the cold

Due to the summer construction, climate changes, such as sudden rainfall, will make the temperature drop suddenly. The sudden drop in the surface temperature of the concrete will make the surface temperature contraction and production of surface temperature shrinkage cracks.

5. Increase in the amount of cement and water-cement ratio in construction increases the plastic shrinkage deformation of concrete.

Summer construction in the mixing, transport, and other processes due to evaporation and other factors easily causes water loss in the concrete mixture. It makes it easier to reduce the ease of use. Therefore, it is easy to increase the amount of cement and water-cement ratio in construction to improve the ease of concrete, and the increase in the amount of cement and water-cement ratio is more likely to cause contraction when the contraction is restrained. It is easy to form cracks.

6. In the construction of hardened concrete at high temperatures, the solid formation temperature determines the concrete's base length. When the whole cools down, it is from this length and temperature contraction, and it is very easy to produce the overall temperature contraction cracks, such as the production of pavement broken plate.

Concrete additives Supplier

TRUNNANO is a reliable concrete additives supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

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We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

What is polycarboxylate superplasticizer?

Polycarboxylate superplasticizer is the world's most advanced concrete superplasticizer (water reducer) with the highest technological content, application prospects, and comprehensive performance. Polycarboxylate superplasticizer is a compound product of carboxylic acid grafted multi-polymer and other effective additives. A water reducer is a concrete admixture that can decrease the required amount of mixing water without altering the concrete's slump. It can disperse cement particles once added to the concrete mixture, enhancing its workability and fluidity. This results in a reduction in both unit water and cement consumption, effectively saving on cement.

Features of polycarboxylate superplasticizer

1. Polycarboxylate high-performance water-reducing agent has low dosage and high water-reducing rate, which can be as high as 45%.

2. Over time, the polycarboxylate high-performance water-reducing agent has a small slump loss， which means that the rate of slump loss for ready-mixed concrete is less than 5% within 1 hour and less than 10% within 2 hours.

3. The improvement in strength is impressive. The 3D compressive strength of concrete increases by 50-110%, while the 28-day and 90-day compressive strength increase by 40-80% and 30-60%, respectively.

4. Using Polycarboxylate as a high-performance water-reducing concrete agent has several benefits. These include excellent workability, no segregation or bleeding, and a uniform color appearance of the finished product. Additionally, when used to prepare high-grade concrete, it promotes good cohesion and ease of mixing.

5. The air content of this material is moderate and does not negatively impact the elastic modulus of concrete. Additionally, it has excellent frost resistance and durability.

6. A polycarboxylate high-performance water-reducing agent can help lower the initial heat produced during cement hydration. It is particularly advantageous for construction projects involving large volumes of concrete carried out during the summer season.

7. The polycarboxylate superplasticizer boasts exceptional versatility, displaying remarkable compatibility with cement and admixtures, outstanding temperature adaptability, and excellent compatibility with different types of cement and admixtures, which solves the problem of using other water-reducing agents. The problem of poor compatibility between water-reducing agents and gelling material.

8. Polycarboxylate superplasticizer can significantly reduce concrete shrinkage. Its freeze-thaw and carbonation resistance o is notably superior to regular concrete, significantly improving concrete volume stability and long-term durability.

9. The alkali content of polycarboxylate superplasticizer is extremely low, and the alkali content is ≤0.2%, which can effectively prevent the occurrence of alkali-aggregate reaction.

10. The superplasticizer made of polycarboxylate is very stable and does not separate or form sediment during long-term storage. It also does not crystallize at low temperatures.

11. The polycarboxylate superplasticizer is an eco-friendly product that doesn't contain formaldehyde. It's designed to be safe for the environment.

12. Polycarboxylate superplasticizer has good economic benefits, and the overall project cost is lower than that of other types of products. It can save 15-25% of cement under the same strength condition.

What is polycarboxylate superplasticizer used for?

Polycarboxylate superplasticizer is suitable for pumping or normal concrete projects with strength grades of C15~C60 and above. It is especially suitable for preparing concrete projects with high durability, fluidity, high slump retention, high strength, and high requirements on appearance quality. Polycarboxylate superplasticizer is extremely beneficial for preparing high-fluidity, self-compacting, and clear-faced concrete. Ordinary water reducer is suitable for concrete with a daily minimum temperature above 5 °C, and polycarboxylate superplasticizer is suitable for concrete with a daily minimum temperature above 0°C and is suitable for preparing large fluidity concrete, high-strength concrete, and steam-cured concrete.

What is the function of superplasticizers in concrete?

Superplasticizers are commonly used in dry-pressed concrete to improve workability, enhance concrete compaction, increase density, and improve the surface finish of concrete products.

Polycarboxylate Superplasticizer Supplier

TRUNNANO is a reliable supplier polycarboxylate superplasticizer with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for polycarboxylate superplasticizer, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

What is concrete foaming agent?

Concrete foaming agent is a type of admixture that helps create stable and uniform foam by reducing the surface tension of a liquid. It is commonly used for producing foamed concrete. A foaming agent is a substance that creates a lot of foam when air is introduced into its aqueous solution through mechanical force. A surfactant or surface-active substance relies on surface activity to produce foam. Without surface activity, it cannot be a foaming agent. Therefore, surface activity is crucial to the creation of foam.

Features of concrete foaming agent

1. Concrete foaming agent is a large surfactant supramolecular aqueous solution.

2. Its hydrophilic groups form a two-dimensional plane structure through chemical bonds, and many hydrophobic groups are bonded to one side of the two-dimensional plane, so its foam performance can be compared with sodium dodecylbenzene sulfonate. It is comparable to that, and its foam is more combined with cement, fly ash, slag, mortar, and other raw materials after contacting it. Bulk density is a foam concrete foaming agent for foam concrete made of various mixtures.

3. Concrete foaming agent also has the advantages of low absorption rate, strong foaming rate, balanced density, long-lasting foam, high strength, etc. It is an environmentally friendly and powerful foaming agent.

What is concrete foaming agents used for?

1. Concrete foaming agent can be used for heat insulation layer of ground radiant heating and roof heat insulation

2. Concrete foaming agent can be used to fill wall blocks inside and outside buildings, soundproof walls

3. Concrete foaming agents can be used for thermal insulation, moisture-proof, and anti-corrosion of municipal pipelines such as water supply, heating, oil pipelines, etc.

4. Concrete foaming agent can be used in the construction of plant cultivation greenhouses and cold storage

5. Concrete foaming agent can be used to fill the internal voids of tunnels and building gaps

6. Concrete foaming agent can be used for laying the base of sidewalks, sports fields, and courts

How to make concrete foaming agents?

Commercial foaming agents are usually detergent-based, so that you can use an over-the-counter dish soap such as Dawn, Axion, Seventh Generation Natural, or any other brand of dish soap. Dilute the cleaner 1 in 40, or 2 cups of cleaner in 5 gallons of water.

Concrete Foaming Agent Supplier

TRUNNANO is a reliable concrete foaming agent supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality concrete foaming agent, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.

What is Polycarboxylate Superplasticizer?

Polycarboxylate superplasticizer (PCE) is a comb-like polymer with an anionic backbone and several non-ionic vertical chains, usually consisting of polyethylene glycol.

It is a kind of cement dispersant and high-performance water-reducing agent which is used in cement concrete.

Widely used in Bridges, tunnels, DAMS, highways, high-rise buildings, and other projects.

The product is green, non-flammable, non-explosive, and can be safely transported by train and car.

Is Polycarboxylate Superplasticizer a dangerous chemical?

Polycarboxylate Superplasticizer is a cement dispersant in the application of cement concrete, which can be divided into two types chemically, with the main chain as methacrylic acid, the side chain as a carboxylic acid group, and MPEG(Methoxy polyethylene glycol), polyester type structure.

The other main chain is polyacrylic acid; the side chain is Vinyl alcohol polyethylene glycol, a polyether-type structure. It is not classified as a dangerous chemical.

Features of Polycarboxylate Superplasticizer

1. The polycarboxylate superplasticizer has the characteristics of a high water reduction rate, slump resistance, high early strength, low foaming, low energy consumption, and low alkali, etc.

2. The third monomer is introduced. It has a good molecular weight regulation function. The synthetic superplasticizer has the advantages of good workability with concrete, low viscosity, and uniform molecular weight distribution.

3. The higher unsaturation ensures the higher effective content of the superagent synthesized in the later stage, which makes the most favorable guarantee for a high water reduction rate and high slump protection.

4. With Polycarboxylate Superplasticizer, more slag or fly ash can be used to replace cement, thereby reducing costs.

What is Polycarboxylate Superplasticizer used for?

Due to its good performance, it is suitable for precast and cast-in-situ concrete, reinforced concrete, and prestressed concrete of high-speed railways, passenger dedicated lines, industrial and civil buildings, roads, bridges, ports, terminals, airports, and other projects. It is especially suitable for projects requiring high concrete slumps and long construction time, such as nuclear power projects.

Polycarboxylate Superplasticizer Supplier

TRUNNANO is a reliable Polycarboxylate Superplasticizer powder supplier with over 12-year experience in nano-building energy conservation and nanotechnology development.

If you are looking for high-quality Polycarboxylate Superplasticizer powder, please feel free to contact us and send an inquiry. (sales@cabr-concrete.com)

We accept payment via Credit Card, T/T, West Union, and Paypal. TRUNNANO will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.