Construction Precast Development

The earlier the curing period after pouring concrete, the greater the impact on the concrete.

In practice, it has been found that if a standard curing of 7 days can be guaranteed, the compressive strength of concrete at 28 days can basically reach about 90% of the standard curing.

If no curing measures are taken for concrete test blocks, the impact on the strength of low strength grade concrete is greater than that of high strength grade concrete.

The reason is that low strength grade concrete has low early strength, low compactness, and easier internal moisture loss, resulting in a decrease in later hydration degree.

The engineering entity structure is much larger than the test block, and the surface curing is insufficient.

The degree of decrease in internal concrete strength is smaller than that of the test block, but the loose and powdery phenomenon of the surface concrete directly leads to low rebound strength.

Steel Rebar Chairs

Taking C30 as an example, it is common for engineering entities to have a rebound strength lower than the standard curing specimen by more than 5MPa without curing.

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At present, it is very important to use the rebound method to detect the construction quality of concrete structures in construction projects.

The principle is mainly based on the hardness and strength of concrete.

Under the action of elasticity, the impact force of the steel hammer is transmitted to the surface of the concrete, and the initial function is redistributed.

Magnetic Thread Disc

In the case of plastic or residual deformation, the concrete absorbs some of its capacity, and other capacities will reach the heavy hammer to ensure the rebound height of the steel hammer.

Combined with the positive correlation between this height and the strength of the concrete, the strength of the concrete material itself can be effectively calculated.

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In October 2025, the first three quarters performance announcement disclosed by Western Construction showed that the company achieved a revenue of 13.

881 billion yuan, a year-on-year decrease of 7.

57%, and a net profit attributable to the parent company was a loss of 198 million yuan, a significant year-on-year decrease of 2141.

86%.

The performance of turning from profit to loss reflects multiple pressures on the company’s management.

From the financial data perspective, the deterioration of the profit side is particularly prominent, with a weighted average return on equity as low as -2.

44% in the first three quarters and a gross profit margin of only 6.

57%, further shrinking from 8.

45% in the same period last year and far below the industry average.

Rebar Saddles

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With the urgent global demand for sustainable development and intelligent construction, the construction industry is actively seeking low-carbon and efficient innovative solutions.

Swift Lift Void Former

3D printing concrete technology has emerged, which does not require templates and can freely form complex structures, greatly improving construction efficiency and reducing material waste.

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As a commonly used method for non-destructive testing of the main structure of construction projects, the rebound method plays an important role in engineering quality supervision.

The following is a study on the influencing factors, countermeasures, and problems discovered in the supervision of engineering based on the rebound method for strength measurement.

Spread Anchor

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For the study of the strength law of low-temperature cured concrete, Li Fen et al.

in China studied the development law of compressive strength of medium and low-grade concrete under negative temperature conditions, and fitted the relationship between compressive strength and age using a logarithmic function.

Here, the ages are 3d, 7d, 28d, and 56d.

Edge Lift Anchor

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The transverse joint divides the entire length of the dam into several sections of 15-24m along the axis of the dam, and the joints between the sections are called transverse joints.

Erection Anchor

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In industrial floors, warehouse workshops, and other places, we often see floors that are as smooth as new and as hard as stone.

This is often attributed to a material called a sealing curing agent.

It is not like epoxy flooring that covers the surface of concrete, but rather like injecting a strong needle into the concrete, fundamentally improving its performance through deep penetration and chemical reaction with the concrete.

Concrete Lifting Clutch

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During the molding process of concrete, various factors such as materials, processes, and environmental conditions often lead to the formation of bubbles on the surface of the concrete.

Plastic Rebar Chairs

A small amount of bubbles will not have a significant impact on components or buildings, but too many bubbles will bring a series of problems.

(When the air content of concrete increases by 1%, the compressive strength at 28 days decreases by 5%.

– Taken from Baidu Scholar).

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Rebar Wheel Spacers

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1 The strength grade of concrete must meet the design requirements.

The specimens used to test the strength of concrete should be randomly selected at the pouring site.

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