It should be noted that these ratios are recommended ratios under standard conditions, and may need to be adjusted appropriately according to the size and requirements of sand and gravel during actual construction.
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Precast News From China
It should be noted that these ratios are recommended ratios under standard conditions, and may need to be adjusted appropriately according to the size and requirements of sand and gravel during actual construction.
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On January 1, 2026, the Announcement of the Ministry of Finance and the State Administration of Taxation on the Connection of Value added Tax Preferential Policies after the Implementation of the Value added Tax Law (Announcement No.
10 of 2026, hereinafter referred to as “Announcement No.
10″) was officially implemented.
The implementation of this policy marks the official end of the simple taxation model that the concrete industry has continued for nearly 17 years, from 3% simple taxation to 13% general taxation.
The concrete industry is facing new challenges in tax compliance and cost control.
How can concrete companies respond quickly and effectively to policy changes, maintain their operating bottom line, and reduce tax costs? Today, Lawyer Wanfang brings you the following plan:.
The common quality problems of concrete are mainly divided into five categories: raw materials, mixing, pouring, curing, and finished product defects.
I have compiled the most practical and easily understandable version on site:.
Chapter 5 is the core chapter of civil engineering, which will be explained one by one from three parts: concrete, steel bars, and formwork.
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The amount of water added to concrete during the mixing process is called mixing water, which is calculated based on the water cement ratio in the mix proportion (referring to the weight ratio of water to cement in concrete).
Mixing water consists of two parts, one part is compound water and the other part is free water.
Compound water is necessary for the hydration of cement, and sufficient compound water is needed to ensure the full hydrolysis and hydration of cement particles, the formation of crystals and setting.
However, this part of the water consumption is relatively small, generally only accounting for a quarter of the mixing water.
The remaining water is called free water, which is added to meet operational requirements, such as ensuring the workability and slump of concrete.
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2、 The mix design and application should not only comply with JGJ/T55-2011 “Code for Design of Mix Proportion of Ordinary Concrete”, but also with the relevant national standards, industry standards, and specifications related to the performance requirements and application of concrete, which are currently effective.
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This article will systematically review the main problems in winter concrete construction from multiple perspectives, and propose corresponding quality control measures to provide reference for engineering practice in cold seasons.
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Concrete has become an indispensable material in construction projects.
However, the quality of concrete is affected by multiple factors such as raw material characteristics, mix design, construction technology, and environmental conditions.
Any negligence in any link may lead to quality hazards such as insufficient strength, cracks, and leakage.
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In traditional understanding, after concrete is discharged from the machine, factors such as cement hydration process, aggregate water absorption, and water evaporation result in a gradual decrease in fluidity.
However, the frequent occurrence of the “slow-release” phenomenon in industry practice – that is, the normal flowability of concrete after being discharged from the machine increases abnormally after a period of time, even accompanied by problems such as bleeding, segregation, and stone leakage – not only subverts the traditional law of flowability changes, but also brings multiple hidden dangers to engineering quality, becoming a technical problem that troubles pre mixed concrete production enterprises and construction units.
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Traditional CFRP reinforcement often uses full wrapping (100% coverage) or discrete strips (such as spaced wrapping), which can significantly improve strength and ductility, but have high material costs and complex construction.
This study proposes a novel central band confinement strategy that only applies CFRP bands in the central region of the cylinder, reducing fiber usage while retaining core confinement effectiveness.
The previous plan lacked systematic experimental verification and theoretical modeling, which is a knowledge gap area.
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