A certain mixing plant, with the same strength of C35, used river sand on Monday and replaced it with machine-made sand on Wednesday.
The result is:.
Is the concrete mix still based on experience? Don’t waste cement anymore! Inaccurate mix ratio=cost out of control, this time let the
A certain mixing plant, with the same strength of C35, used river sand on Monday and replaced it with machine-made sand on Wednesday.
The result is:.
The relationship between particle size and gradation of aggregates and concrete
The proportion of particles of different sizes in the aggregate is called the gradation of the aggregate.
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Analysis and determination of cracks in concrete engineering
The cracks generated in concrete structures under load are called stress cracks.
Ordinary concrete components may experience stress cracks when subjected to 30% to 40% of the design load, and the ultimate failure load of such components is often more than 1.
5 times the design load value.
As long as the width of such cracks meets the specifications, it will not affect the safety of the structure.
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Several issues to be noted in concrete mix design
In the current mix proportion design specifications in China, JGJ55-2011 “Code for Design of Ordinary Concrete Mix Proportion” is one of the commonly used mix proportion design methods.
In JGJ55-2011 “Code for Design of Ordinary Concrete Mix Proportion”, the basic ideas and parameters of ordinary concrete mix proportion design are specified.
This code is based on the statistical results of a large number of experiments and uses the Baum formula (i.
e.
water cement ratio rule) to design the mix proportion of concrete.
Therefore, this code is applicable to the design of ordinary concrete mix proportion.
For special concrete and high-strength concrete, it is emphasized that based on experience, appropriate materials and mix proportions must be selected through multiple repeated tests using the materials used in the project.
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China’s first “underwater self-protection” 3D printed concrete technology leads the revolution of intelligent underwater construction
Professor An Xuehui from Tsinghua University and Professor Li Pengfei’s team from Chongqing Jiaotong University have completed systematic experimental research in the field of underwater 3D printed concrete.
Together, they have successfully developed underwater self-protection 3D printed concrete technology, which effectively solves industry problems such as easy dispersion, poor molding, and weak interlayer bonding of underwater concrete by innovatively introducing external protection mechanisms for water bodies.
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What are the effects of stones not hanging slurry on the performance of concrete?
The absence of stone slurry will significantly weaken the strength, durability, and overall structural performance of concrete, which is a key defect in concrete quality control.
The specific impacts are as follows:.
The main reason why stones in concrete do not hang slurry
The main reasons why stones in concrete do not hang slurry include design defects in mix proportions, problems with raw materials, and improper construction control.
The core issue is that insufficient slurry or poor cohesion prevent effective encapsulation of aggregates.
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How to prevent pile breakage when pouring concrete underwater?
1) During the process of pouring concrete, due to the detachment of the conduit, mud enters the conduit, causing the mud in the hole to suddenly and rapidly drop.
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Analysis of Reasons for Abnormal Concrete Condensation
The abnormal setting time of concrete generally manifests as three types: excessive slow setting, rapid setting, and false setting.
There are many factors that can affect the occurrence of abnormal setting in cement concrete, including concrete admixtures, cement, admixtures, environmental temperature, and wind speed.
From the current quality status of concrete engineering, improper types and dosages of retarders, unsuitability between additives and cement, and environmental temperature are the main reasons for abnormal setting of cement concrete and even concrete engineering accidents.
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