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Question: For C55 concrete, all test block inspection reports are qualified, but for the structure inspection with a rebound tester, we took 12 sets of data and found that the strength is only around C45.
Moreover, the carbonation depth is calculated as zero.
The concrete pouring has been completed for more than two months.
May I ask what is going on?.
Generally, for every 10 ℃ increase in concrete temperature, the water consumption of concrete increases by 3% to 5%, the air content decreases by 20% to 30%, the setting time is shortened by 1 to 3 hours, and the strength decreases by 2 MPa.
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Everyone knows that the mix proportion of ready mixed concrete is the primary issue in concrete quality control.
In addition to being a key link in delivering products that meet customer requirements, it is also the basic basis for determining whether the product is economically reasonable.
To ensure the production quality of ready mixed concrete, reasonable and economical concrete mix design is based on the foundation of raw materials.
So concrete raw materials are the foundation for achieving product quality and reflecting economic benefits, and controlling concrete raw materials is particularly important.
But we believe that it is more important to understand the essence of concrete raw materials, as the vicious competition between pre mixed concrete companies and concrete material suppliers has led to a mixed market of concrete raw materials.
Therefore, recognizing the essence of raw materials and the “material based construction method” is of utmost importance for concrete quality control.
Based on my years of experience in the concrete industry, I would like to briefly discuss and share my insights and responses to the application of concrete raw materials with my peers.
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Frost heave is an important form of damage to cement concrete pavements in cold regions of airports, which deteriorates performance, shortens service life, and poses a serious threat to flight safety.
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Poor pumpability usually refers to poor fluidity and high resistance of concrete during pumping, which can easily lead to problems such as pipe blockage and segregation.
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The commonly used technical standard system in concrete enterprises covers the entire process of raw materials, mix design, production control, construction application, and quality acceptance, and is the core basis for ensuring product quality and engineering safety.
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The construction process of lightweight aggregate concrete is basically the same as that of ordinary concrete.
However, due to the low bulk density, porous structure, and high water absorption rate of lightweight aggregates, the formulated lightweight aggregate concrete also has certain characteristics.
Only by paying sufficient attention during the construction process can the construction quality of the project be ensured.
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In the current concrete industry, due to the weak quality awareness and lack of integrity of some raw material suppliers, as well as the scarcity of resources, the quality of raw materials is unstable, which leads to the instability of concrete quality.
How should engineers on the front line of construction act to ensure the quality of concrete to the greatest extent possible when there is no time for experimental testing and trial mix adjustment? This is a problem that seems “inconvenient” to discuss, but objectively exists, frequently occurs, and urgently needs to be solved.
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In the first quarter of 2026, global infrastructure investment continued to increase, with overseas real estate recovery, energy infrastructure, transportation network, and mineral supporting projects concentrated, driving the steady increase in demand for ready mixed concrete (commercial concrete).
As April is the traditional peak season for overseas construction, there have been significant changes in concrete production, prices, imports and exports, and raw material costs in the core regions of Southeast Asia, the Middle East, Africa, Latin America, and Europe.
This report focuses on the latest market situation, supply and demand pattern, cost trend, project opportunities and risk tips of the overseas mainstream market in April.
The data is compiled by integrating the import and export data of the Global Building Materials Association, national statistical bureaus, customs, quarterly reports of overseas leading commercial concrete enterprises, and real-time quotations of bulk commodities.
The content is popular and the focus is clear, and it is suitable for the release, forwarding and exchange of industry official account.
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