Construction, bridge and other industries are completely inseparable from concrete and concrete admixtures during construction, and their development trends are a topic of concern to everyone. Practitioners must pay attention to its development in order to better serve their work.
The country attaches great importance to the development of concrete and has issued a series of strong policies and regulations, which provide guarantee for the rapid and healthy development of ready-mixed concrete and promote the following six major trends in the concrete industry:
1. Use of construction waste, industrial waste, etc.
2. High strength, high performance, green energy saving and environmental protection
The so-called greenness is judged by the following indicators
1. Use green cement to reduce dust emissions;
2. Save cement usage and reduce gas emissions;
3. Add active grinding admixtures to cement;
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4. Add high-performance admixtures;
5. Use high-performance concrete to reduce the amount of cement and concrete;
6. Recycle concrete.
3. Concrete has good durability
4. Wide use of lightweight concrete
With its good characteristics, lightweight concrete is widely used in energy-saving walls. Materials have also been applied in other aspects. At present, the main applications of lightweight concrete in China are cast-in-place roof insulation layers, lightweight wall panels, and compensation foundations. However, by making full use of its good characteristics, its application fields in construction projects can be continuously expanded, the project progress can be accelerated, and the project quality can be improved. The details are as follows:
⑴ Used as a retaining wall.
⑵Build sports fields and track and field tracks.
⑶As a sandwich component.
⑷ Pipeline backfill.
⑸Lean concrete filling layer.
⑹Roof slope.
⑺Support of storage tank feet.
⑻Used for landscaping.
⑼Others. Foam concrete can also be used for insulation filling of firewalls, sound insulation floor filling, tunnel liner backfilling, and isolation of power supply and water pipelines.
5. High strength and high performance: there are more and more self-compacting and self-leveling concretes
6. Composite materials will become the leading building materials in future concrete engineering structures
The characteristic of composite materials is that two or more component materials are combined together to produce a new matrix material, which has better performance than any one component material. From the basic material a new material can be generated that is more suitable for the building and more suitable for the surrounding environment.
Reflection of the development trend of concrete admixtures
(1) Design admixtures according to usage requirements
Concrete used under different conditions also has different requirements for admixtures , and sometimes even require admixtures to have multiple functions. The multifunctionalization of concrete admixtures can be understood as designing admixtures based on performance. Designing admixtures based on performance can reduce the cost of concrete materials, meet the requirements of "design based on performance" for high-performance concrete, and optimize the performance of admixtures and concrete. This has very important theoretical significance and engineering application value for designing concrete admixtures based on performance and studying their mechanisms.
Chemical synthesis and physical compounding are two technical ways to design concrete admixtures according to usage requirements. As long as the usage requirements are met, no matter what approach is taken, it is advisable. It is particularly worth mentioning that the molecular structure characteristics of the polycarboxylic acid-based water-reducing agent can be changed according to the usage requirements, so that the polycarboxylic acid-based water-reducing agent can be developed in a targeted manner to meet the actual needs of different projects.
(2) Independent innovation of new green and environmentally friendly admixture products
Enterprises in the admixture industry must focus on independent innovation of technology research and development, technology updates and technology upgrading to truly compete with the competition This creates differentiation, and it is a differentiation that is difficult to imitate. In addition, efforts must be intensified to develop new green and environmentally friendly additive products that are harmless to human health and non-polluting to the environment throughout the entire process from production, construction to building use. In addition, we develop chlorine-free, low-alkali or alkali-free additives as well as harmless and waste-recycling products.
(3) Develop high-performance concrete anti-crack internal curing admixtures
The biggest obstacle in the engineering application of high-performance concrete (or low water-cement ratio concrete) is the problem of early cracking . Due to chemical shrinkage during the hydration process of cement, voids are formed in the cement paste, the internal relative humidity is reduced and autogenous shrinkage occurs, resulting in cracking of the concrete structure. For high-performance concrete, while strengthening external wet curing, internal curing should also be carried out; therefore, in response to the anti-cracking requirements of high-performance concrete, research and development of internal curing admixtures will be a necessary technical approach.
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