Precast News From China
At the construction site, my signature not only represents acceptance, but also a responsibility for the project lifecycle.
And every stroke of confidence comes from the homogeneity and stability of concrete – this is the most easily overlooked but fatal pain point in small volume construction.
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Judging the quality of concrete does not require complex instruments.
By mastering the following four practical skills, one can quickly make preliminary judgments.
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Coal is the main source of energy in China, and the development of coal resources plays a key role in supporting China’s economic and social development.
Coal gangue is a hard rock that accompanies coal during the coal mining process, accounting for approximately 10% to 20% of coal production.
The accumulation of coal gangue not only occupies a large amount of land resources, but also leads to the continuous deterioration of the ecological environment.
Therefore, exploring scientific and efficient ways to develop and utilize coal gangue is crucial for achieving sustainable development of the coal industry.
Nano silica (NS) exhibits significant advantages in enhancing the performance of concrete, mainly attributed to its filling effect and volcanic ash effect.
The filling effect enhances the internal density of concrete, while the volcanic ash effect promotes cement hydration reaction, thereby optimizing the microstructure of the interface transition zone.
In addition, by using reasonable mixing techniques to bond NS concrete, its mechanical properties can be significantly improved.
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In large-scale housing construction projects, the pouring of large volume concrete is like the “texture” of a person, and the quality of concrete pouring is related to the “health” of this massive body.
Recently, the Shenyang Project Department of China Railway Sixth Bureau Beijing Company successfully developed and applied a new comprehensive technology solution that integrates “material innovation+intelligent temperature control+fine construction”, effectively overcoming traditional problems such as concentrated release of hydration heat and insufficient waterproof performance of large volume concrete, and building a strong construction quality barrier for the high-quality construction of Shenyang Hunnan Science and Technology City.
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Concrete is a heterogeneous brittle material formed by mixing sand and gravel aggregates, cement, water, and other external materials.
Due to a series of problems such as concrete construction, deformation, and constraints, there are numerous micro pores, air pockets, and micro cracks in the hardened concrete.
It is precisely because of these initial defects that the concrete exhibits some heterogeneous characteristics.
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With the widespread application of 3D concrete printing (3DPC) technology in the construction field, the lack of steel reinforcement leading to insufficient tensile performance has become a key bottleneck.
For this reason, scholars such as Yan Zitong first proposed a technical solution of using fiber-reinforced polymer (FRP) to constrain 3D printing of ultra-high performance concrete (FC3DPU), and studied its mechanical performance enhancement mechanism through an axial compression test system.
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Foam concrete is widely concerned because of its excellent performance of heat insulation, fire prevention, sound absorption and low density.
Conventional foam concrete uses ordinary Portland cement (OPC) as the binder, but the energy consumption of cement production is high.
Each ton of cement emits about 0.
85 tons of CO ₂, accounting for nearly 8% of global anthropogenic CO ₂ emissions.
Geopolymer foam concrete (GFC) combines the lightweight and thermal insulation characteristics of foam concrete and the environmental protection and high-performance characteristics of alkali activated bonding system, and uses industrial by-products such as fly ash (FA) as the main binder to significantly reduce greenhouse gas emissions.
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During the structural construction process, the project department often discovers varying degrees of quality problems on the construction site, including slag inclusion in construction joints (floor slabs), exposed steel bars, concrete honeycombs, rough surfaces, missing edges and corners, floor cracks, and uneven door and window openings.
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