With the continuous improvement of grinding technology in recent years and the excitation of the activity of superfine slag powder, when it is added into concrete as a miserable mixture, it can give full play to its physical and chemical properties and other potential activities, and the reduction of hydration heat can effectively ensure the durability of concrete components to increase wear resistance and economy.

As for air-entraining agent, its principle is to add some evenly mixed and stable small bubbles into the concrete to ensure that the tax reduction effect reaches 6%~9%, which is conducive to the improvement of its stability and can reduce the occurrence of bleeding and segregation in the concrete.

Fixing Socket Cross Hole Nail Plate

The best way to improve the load effect is to use reinforcement combination instead of spacing reinforcement; In prestressed concrete members, the main reinforcement and prestressed reinforcement bear the force together, and the non-prestressed reinforcement provides a buffer effect when the prestressed reinforcement has brittle failure.

The main reason is that the construction unit did not encrypt the stirrups in the concrete frame structure nodes according to the requirements of the drawings during the construction process, and they did not understand the importance of setting two groups of stirrups in the concrete frame nodes, which would bring great hidden dangers to the safety of the engineering structure.

In order to improve the strength and ductility of the joint and the integrity of the joint, it is necessary to restrict the core concrete of the joint, and set two groups of stirrups to achieve good results.

1.1.2 Compared with the progressiveness of ordinary mixing, vibratory mixing is now recognized as the most economical method to improve mixing quality and efficiency at home and abroad.

The precast buildings are mostly crushed and damaged by concrete frame nodes.

At the same time, the development of concrete precast buildings is the only way to comprehensively improve the quality and quality of public housing, and the improvement of seismic performance of buildings is the guarantee of people’s lives.

In addition, through research, it is found that if a stronger stirrup is added to this high-strength steel bar, it will have a stronger binding capacity on the concrete, reduce the bending of the longitudinal reinforcement, and improve the brittleness of the component failure, which provides a new way and method to ensure the ductility and seismic performance of high-strength concrete precast columns.

The test shows that air entraining agent can improve the slump, flow and plasticity of concrete mixture.

1.3 Comparative study on the connection method of precast component nodes 1.3.1 The stirrups of precast structure nodes should be densified in the earthquake with large magnitude.

In addition, the bearing capacity and reinforcement method of precast concrete members also have a great impact on the mechanical properties of precast buildings.

Slag concrete is characterized by its good plasticity and water retention.

The configuration of non-prestressed reinforcement can significantly improve the ultimate displacement value of precast members, enhance the deformation capacity of members under earthquake, and thus improve the overall seismic performance.

As the frame node is the key part of the structure, once damaged, it is difficult to repair, or even cause the collapse of the whole frame.

Their research found that if the concrete is mixed and vibrated at the same time, the cement and water can be fully dispersed and hydrated, and the concrete will be uniform in both macro and micro in a short time.

Because of the advantages in performance, cost and other aspects, we believe that this form of mixed reinforcement is the best scheme for improving the seismic performance of concrete precast units.

Researchers from Chang’an University have studied concrete mixing theory for a long time, and initially designed concrete vibration mixing equipment.

Polycarboxylic acid added in cement can make concrete free from segregation and bleeding, and can effectively ensure the enhancement of concrete volume stability and the strength level in the early and late stages.

The relatively wide application is a new type of water-reducing agent called polycarboxylic acid.

Compared with traditional buildings, the research on seismic performance of precast buildings is still less.

Compared with the ordinary reinforcement, this kind of reinforcement with higher strength can play a greater role in improving the seismic performance and stability of the test piece.

Under vibration mixing, the air content of concrete is significantly increased, and the fluidity of fresh concrete is also significantly higher than that of ordinary mixing.

The development of precast concrete buildings is an effective way to promote energy conservation, emission reduction and consumption reduction and green production in the construction industry; It is an efficient catalyst to drive construction industrialization and improve production efficiency.

Nowadays, some environment-friendly and efficient water-reducing agents have been widely used, and the effect is ideal.

What is the seismic performance of precast concrete buildings? What is the development of this research in China? The research on seismic performance of precast concrete buildings has been involved at home and abroad.

Therefore, it is essential to compare and study the seismic performance of concrete precast buildings.

Polycarboxylic acid has good compatibility with various kinds of cement.

1.2 Comparative study of different reinforcement methods of precast parts 1.2.1 Comparison of the effect of longitudinal reinforcement and stirrup strength When carrying out the equal volume replacement of reinforcement, compared with the seismic performance of the test piece, the strength problem is more influential.

Effectively improve the workability and workability of concrete, and improve the volume stability of concrete precast units.

Through the comparison and analysis of a large number of test data, it is found that when the non-prestressed reinforcement with the reinforcement strength ratio of about 53% is configured, the seismic resistance of the concrete precast units can be effectively improved.

This is of great benefit to the improvement of the stability of the stressed reinforcement and the strengthening of the joint strength..

It can be seen that we can increase the air content of concrete and improve the bearing capacity of concrete by selecting the way of vibration mixing.

At present, the focus of seismic performance research of precast buildings is on joints.

1.2.2 Effective action of non-prestressed reinforcement and reinforcement combination The load of non-prestressed reinforcement specimen increases with the increase of reinforcement strength ratio.

Therefore, the seismic performance of concrete precast buildings still needs further comparative study.

1 Analysis and comparison 1.1 Comparative study on the bearing capacity of precast concrete components 1.1.1 The influence of admixtures and admixtures on the bearing capacity of concrete Admixtures will have a greater impact on the bearing capacity of concrete, among which water-reducing agent, air-entraining agent and slag are the most widely used.