precast-tech

TBM excavation is a commonly used construction technique for water conservancy tunnels.

The excavation and lining processes are closely connected, and the working space is limited.

The efficiency, quality, and safety control requirements for synchronous lining construction are extremely high.

Concrete Lifting Clutch

Synchronous lining can achieve parallel operation of tunnel excavation and concrete lining, effectively compressing the total construction period and improving construction continuity.

This article combines engineering practice to summarize the construction process, process points, quality control, and on-site management experience of synchronous lining concrete in TBM sections.

It also outlines the construction difficulties and countermeasures, which can provide reference and guidance for similar TBM synchronous lining projects in water conservancy tunnels.

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Among concrete admixtures, water reducing agents are an important type.

Water reducing agents have been widely used in concrete preparation, and the dosage has always been a difficult point in the use of water reducing agents.

Lifting Socket

This article combines the factors that affect the performance of water reducers and the mechanism of action of water reducers to study the determination method of the optimal dosage of concrete water reducers, in order to achieve the maximum performance of water reducers.

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The common water seepage areas in concrete structures mainly include roofs, exterior walls, basements, construction joints, deformation joints, post pouring strips, bolt holes through walls, and the surrounding areas of door and window openings.

Plastic Rebar Chairs

These areas are prone to becoming water seepage breakthrough points due to their structural characteristics or complex construction processes.

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Concrete is the most commonly used construction material in current construction projects.

Reasonable concrete construction can ensure the functionality and safety of buildings, reduce the probability of safety and quality hazards.

Coil Loop Insert

Therefore, appropriate construction measures should be taken based on the actual situation to reduce the impact of external factors on construction and ensure that the performance of concrete meets the requirements.

In actual concrete production, the quality requirements of cement are very important.

Therefore, based on this, a simple study of concrete production is conducted, followed by an analysis of the corresponding cement quality requirements in concrete production, with the aim of ensuring the quality of concrete and ensuring that it meets actual needs.

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This article “The Past and Present of Bubble Holes on the Surface of Aluminum Formwork Concrete” is written by Hunan Sixth Construction Third Branch Company to address the common problem of surface bubble holes in aluminum formwork construction concrete.

Based on engineering examples and relevant information, it is worth referring to and learning from.

Embedment Plate

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Based on practical work and theoretical research, this article intends to systematically sort out and identify various sources of errors in rebound testing at multiple levels, and explore an effective method from the aspects of technical management, job specifications, and data processing, laying a solid theoretical and technical support for further improving the accuracy and reliability of rebound testing.

Fixing Socket

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Concrete admixtures are the “technical soul” of modern concrete, and their adaptability to cementitious materials, aggregates, and mixing water not only determines the construction performance of concrete, but also directly affects its strength and durability.

Fixing Socket

On the front line of production and construction, through intuitive observation and comprehensive judgment of hand feel, various phenomena are interrelated and mutually confirmed, accurately identifying the good adaptability of additives.

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Concrete strength is the core indicator for measuring structural quality, and its development is closely related to curing conditions.

Standard curing and same condition curing are two commonly used methods in engineering, and the difference in strength of the obtained specimens directly affects the judgment of the actual bearing capacity of the structure.

Clarifying the patterns of these differences is not only the key to resolving disputes in strength assessment in engineering, but also provides direction for optimizing maintenance processes.

Previous studies have highlighted the impact of maintenance environment on strength.

Rebar Bolsters

Next, we will delve into the underlying mechanisms of strength changes under two maintenance methods and reveal the specific patterns of differences.

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Due to differences in desulfurization processes and coal quality among power plants, the composition of desulfurization ash is not fixed.

Therefore, using desulfurization ash may not necessarily slow down the setting of concrete.

Crown Foot Anchor

When the proportion of calcium sulfite in desulfurization ash is high, it will cause poor compatibility between cement and admixtures, decreased stability of concrete, increased drying shrinkage, and delayed setting of concrete, with a delay time exceeding 48 hours or even longer.

And the later strength of concrete may also decrease.

There is data indicating that when the content of calcium sulfite reaches 60%, desulfurization ash will reduce the 90 day strength of concrete by 10MPa.

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The author of this article is Wang Huaibei, published in “Construction Workers”.

During the construction process, there are safety hazards in the foundation engineering as long as it is not backfilled for a day.

Swift Lift Void Former

Both the construction unit and the supervision unit hope to complete the foundation engineering construction as soon as possible.

But we have found that many construction units start pouring concrete without completely draining the accumulated water in the foundation pit, especially when there is a concrete structure under the column pier.

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