Construction Precast Development
Precast News From China
During the concrete pouring process, the fabric should be dispersed to ensure that the concrete mixture is evenly distributed without any accumulation.
When using dump trucks or mixer trucks to unload materials, it is strictly prohibited to concentrate a few points of the fabric to allow the concrete to accumulate.
During the leveling process, construction personnel may easily cause damage to the uniformity of the concrete mixture.
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If 1 cubic meter of concrete is 1 cubic meter of C30 concrete, 1 cubic meter of concrete is approximately equal to 2.
488 tons.
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On September 8th, a frontline research report from the building materials and concrete industry attracted industry attention.
The research recorded the real operating conditions of the mixing plant in Wuhu area: C30 concrete is sold at a price of 310 yuan/cubic meter, with a production cost of 320 yuan/cubic meter, and 10 yuan per cubic meter sold.
However, the enterprise still dares not stop production.
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Starting from 2025, 3D printed concrete (3DCP) will skyrocket from laboratory demos to the industry heat list: Singapore will bring structural components to construction sites for on-site printing, silo printers will be sold to 35 countries, and the global market size will gradually increase every year.
What it saves is not gimmicks, but real key accounts for labor, materials, and carbon emissions.
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Steel reinforced concrete columns, with their high bearing capacity, good seismic performance, high construction efficiency, and economic advantages, have widely replaced traditional steel and concrete components and are applied in various engineering scenarios.
Polygonal CFST columns (square, hexagonal, octagonal) have received continuous attention from academia and engineering in recent years due to their flexible architectural design and convenient connection of beam column nodes brought by flat surfaces, which meet the diverse needs of modern architecture.
The ultimate bearing capacity of short column under axial compression is the core parameter of CFST column design, and it is also the basis for understanding the steel tube concrete constraint mechanism and establishing analytical models.
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1 Analysis of the flocculation effect of different contents of flocculants on fine particles of mechanism sand.
In recent years, with the booming development of the construction industry, there has been a shortage of sand and gravel, and the quality is getting worse and worse.
Various types of mountain sand and machine sand with high mud and powder content have to be used.
Due to strict supervision by environmental protection departments, it is explicitly required that wastewater from sand and gravel production enterprises shall not be discharged outside.
Therefore, a large number of sand and gravel production enterprises use coagulants in sewage treatment processes to accelerate the sedimentation of suspended solids in wastewater, enabling them to quickly and effectively recycle the sedimentation treatment of wastewater after sand washing.
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The construction process of multi rod vibration pouring and forming of pier body concrete adopts the method of concrete pumping into the mold, and multiple vibrators are installed in place before the opening of the mold.
During the process of pumping the concrete into the mold, the vibrators are inserted and removed once to vibrate the concrete in one go and pour it into shape, avoiding the method of layered construction of concrete and repeated vibration of vibrators.
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Ultra high performance concrete (UHPC) is prone to peeling and mechanical property degradation at high temperatures.
This study developed a novel high-temperature heat absorbing aggregate (EHA) and systematically investigated its effects on the high-temperature mechanical properties, peeling behavior, and internal vapor pressure of UHPC.
The experimental results showed that the addition of EHA effectively suppressed the peeling phenomenon of UHPC and significantly reduced the attenuation of compressive strength under high temperature of 800 ° C.
The residual strength can be maintained at 48.
8% of the room temperature value, which is 1.
7-2.
0 times higher than traditional UHPC.
The endothermic effect of HA can absorb heat during the heating process, suppress the temperature rise of UHPC, and reduce the formation of microcracks; At the same time, the molten phase of EHA can seal the pores and alleviate the damage of UHPC after infiltrating the matrix.
The pore structure of EHA itself can passively enhance its permeability at high temperatures, promote water vapor transmission, and enhance its anti stripping ability.
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3D printed concrete leaves a large number of weak interfaces due to the “layer by layer stacking”, resulting in strength anisotropy and limited overall reliability.
Professor Zhang Yuanyuan from Shenzhen University and Zhang Guangzhu from Northeast Forestry University proposed the strategy of “in-situ filling of algae bacteria for carbonation regulation” – loading spirulina and carbonate producing Bacillus into porous ceramic particles, sprinkling them into printing mortar, and then curing with rich CO2 to allow calcite to “grow” in weak interfaces, resulting in a synchronous increase in bonding strength and directional homogeneity.
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