Construction Precast Development
Precast News From China
conpd0523 
The rebar dropped several hundred pieces, but the cement and concrete remained unchanged.
This is not accidental – cement and concrete have a completely different pricing logic than steel.
Data source: Building Materials Online ยท Main Material Weekly Report.
The construction progress of concrete dams is constrained by various factors, including climate conditions, construction techniques, structural requirements, and flood impacts, all of which need to be considered comprehensively.
The main factors affecting the construction progress of concrete dams are systematically analyzed from five aspects.
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Concrete construction planning is an important technical document that guides the smooth implementation of concrete engineering.
Scientific and reasonable construction planning requires comprehensive mastery of various basic data, as well as adherence to basic construction laws and technical and economic principles, achieving optimized resource allocation, scientific scheduling, and controllable quality and safety.
The following is a systematic exposition from two aspects: the basis for compilation and the basic principles.
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The technology of hydraulic concrete is constantly developing and evolving with the demand for water conservancy and hydropower engineering construction and technological progress.
From the initial low strength and high fluidity concrete, to plastic concrete, dry hard concrete, and now the widespread application of high-performance concrete, hydraulic concrete technology has gone through a path of continuous breakthroughs and innovation.
Especially in recent decades, significant progress has been made in concrete raw materials, admixtures, construction equipment, pouring processes, and quality management systems, providing solid technical support for the construction of large-scale water conservancy and hydropower projects.
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On July 20th, the national cement market experienced a small-scale decline, mainly concentrated in Sichuan.
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Click on the mini program to view 110 million market prices, manufacturer stamped quotation sheets, and free access to information prices from nearly 40000 issues across the country.
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Concrete technicians can only seek theoretical basis from other standard specifications, but the requirements of the standard specifications are difficult to understand and conflicting with each other.
For example, the “Technical Specification for Waterproofing of Underground Engineering” stipulates that the total amount of cementitious materials should not be less than 320kg/m3, and the amount of cement used should not be less than 260kg/m3, while the “Quality Acceptance Specification for Underground Waterproofing Engineering” stipulates that the amount of cement used should not be less than 300kg/m3, and when active admixtures are added, the amount of cement used should not be less than 280kg/m3.
Due to the fact that most underground or waterproofing projects belong to large volume structures, the above regulations make the provisions on concrete mix proportions in the “Code for Construction of Large Volume Concrete” virtually non-existent.
The standard does not provide detailed explanations for these regulations, leaving concrete technicians at a loss and unable to provide reasonable explanations when consulting relevant departments, which hinders the development of modern concrete.
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Concrete segregation refers to the phenomenon of various constituent materials (such as cement, sand, stone, water, etc.
) in concrete mixtures separating from each other during mixing, transportation, pouring, etc.
, resulting in uneven distribution of each component and affecting the overall performance of concrete.
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The team led by Teng Le and Liu Jiaping from the School of Materials Science and Engineering at Southeast University collaborated with Kamal H.
Khayat from the University of Missouri Science and Technology in the United States to publish a research article titled “Recent Advances in the Hydrological Properties of Ultra High Performance Concrete: A Critical Review” in the Chinese Academy of Engineering journal “Engineering”.
The article focuses on the requirements of advanced construction methods such as self compacting, pumping, spraying, and 3D printing, and systematically analyzes key issues such as how to smoothly construct ultra-high performance concrete (UHPC), how to stably form it, and how to accurately control it.
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