Precast News From China
On April 28th, the national cement market experienced a small-scale decline, with Chongqing and Binzhou dropping by 30 yuan/ton.
On April 28th, there was a small-scale decline in sand and gravel prices nationwide, with Maoming, Yangjiang, Longyan, and Pingdingshan dropping by 1-2 yuan/ton.
On April 28th, the national concrete market experienced small-scale fluctuations, with Yongzhou rising 5 yuan/cubic meter and Sanming, Longyan, and Pingdingshan falling .
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Brazil, as the largest economy in Latin America and one of the world’s largest emerging markets, is currently in a historic window of development for the concrete and cement products industry.
On August 25-27, 2026, the Concrete Show South America in Brazil will be held at the S ã o Paulo Exhibition Center.
This is not only an excellent window for in-depth investigation of local industry demand and connection with first-hand business opportunities, but also a crucial starting point for enterprises to go global in 2026.
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Cracks in the roof fine aggregate concrete protective layer are a common quality problem in roof engineering.
In response to this, China Construction Third Engineering Bureau Third Company has taken a series of construction measures in practical projects to prevent and control the problem of cracks in the roof fine aggregate concrete protective layer, which is worth referring to and learning from.
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On the one hand, the main purpose of watering and curing concrete is to maintain sufficient moisture on the surface of the concrete structure within the specified time, which is the basis of cement hydration reaction.
On the other hand, only by controlling the external conditions of watering and curing concrete can it be conducive to temperature control and avoid the occurrence of cracks.
In the specific process of concrete watering and curing, operators often have a misunderstanding of the purpose of concrete watering and curing, and only understand it as a prescribed operation, without much value to the concrete structure itself.
Before watering and curing concrete, construction personnel should be organized together to learn the process and principles of concrete watering and curing, clarify the purpose of concrete watering and curing, increase the attention of construction personnel to concrete watering and curing, and guide specific behaviors in concrete watering and curing work, thus achieving the improvement of the quality of concrete watering and curing work.
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Memory mnemonic: There are three benefits to pouring through the warehouse: overall improvement of heel stress, economical use of seamless boards, and advanced efficiency improvement for large-scale projects.
Where there is good, there is weakness.
The temperature control requirements are high.
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Should the conclusion of the rebound core method for testing the compressive strength of structural solid concrete in the previous text be qualified or meet the design requirements? This article explains how to draw conclusions about the rebound core method for testing the strength of structural solid concrete.
There is a message asking how to draw conclusions when using the rebound method for testing, providing a brief explanation.
At the same time, it supplements the provisions and understanding of the acceptance standards for structural solid strength testing for reference.
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In existing building safety inspection and appraisal, old community review, and factory reliability assessment projects, the compressive strength of concrete is the core indicator that determines whether the structure can continue to be used, whether it should be reinforced, and whether it can pass the acceptance inspection.
The three most commonly used methods for on-site work are rebound method, core drilling method, and ultrasonic method (ultrasonic rebound comprehensive method).
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Lightweight aggregate concrete has broad application prospects in the field of highways due to its lightweight and good seismic performance.
Lightweight aggregate concrete can significantly reduce the self weight of the structure while ensuring its bearing capacity, which meets the development needs of modern green and low-carbon buildings.
However, the performance of lightweight aggregate concrete is significantly affected by the preparation process, especially the porous and water absorbing characteristics of lightweight aggregate itself, which can lead to unstable workability and large mechanical property dispersion of the mixture.
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(3) The pouring of the dome concrete construction sections C1-C2 is carried out simultaneously by three pump trucks.
The positions of pump truck 1, pump truck 2, and pump truck 3 are shown in the following figure.
Following the principle of symmetrical pouring, pouring is carried out in a clockwise direction.
Pump trucks 1, 2, and 3 are moved once during the pouring process, and each pump truck completes the dome pouring within a 120 ° range.
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The main causes of cracks: cracks caused by external loads (including static and dynamic loads during construction and use); Cracks caused by deformation (including temperature, humidity deformation, uneven settlement, etc.
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Classification of cracks: Classified by the direction and shape of cracks, there are horizontal cracks, vertical cracks, transverse cracks, longitudinal cracks, oblique cracks, and radial cracks; According to the depth of cracks, there are three types: through cracks, deep cracks, and surface cracks; Classified by causes, there are mainly plastic cracks, shrinkage cracks, temperature cracks, and uneven settlement cracks.
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