Concrete additive is an admixture added during concrete mixing. It is mainly used to improve the performance of concrete. From the point of addition ratio of admixture, it is generally not more than 5%. Although it contains a small amount, it has played an active role in improving the performance of concrete and has become an indispensable part of the current development of concrete. The additives used in concrete mainly refer to different types of water reducing agents. The extensive promotion of concrete admixtures has led to significant improvements in the strength of the concrete, its brittleness and its own weight, and has improved the applicability of concrete construction. For example, adding antifreeze to concrete can make concrete construction work in the cold winter. The use of superplasticizers enables the renewal of concrete placement and flow regimes.

Factors Affecting Slump Loss of Concrete-Cement The mineral composition and mineral morphology of cement clinker directly affect the hydration and hardening process of cement and the adsorption of additives, so it has a great influence on the construction performance of concrete. Gypsum in cement components also has a great impact on the slump of concrete. In order to improve the label of cement, cement manufacturers will add appropriate grinding aids to improve the specific surface area of cement which will increase the void ratio of the accumulated weight of cement particles, increase the water demand, and accelerate the hydration reaction of cement, increase the slump loss and poor construction performance.

Chất trợ nghiền xi măng là một chất phụ gia hóa học giúp cải thiện hiệu quả và hiệu suất mài của xi măng. Nó có thể làm tăng đáng kể sản lượng của nền xi măng, cường độ của xi măng ở các độ tuổi khác nhau và cải thiện tính lưu động của nó. Chất trợ nghiền xi măng có thể làm giảm đáng kể hiện tượng hình thành bóng hấp phụ tĩnh điện được hình thành trong quá trình nghiền, và có thể làm giảm xu hướng tái kết tụ của các hạt siêu mịn hình thành trong quá trình nghiền. Chất trợ nghiền xi măng cũng có thể cải thiện đáng kể tính lưu động của xi măng, cải thiện hiệu quả nghiền của máy nghiền và hiệu quả lựa chọn bột của máy phân loại, do đó làm giảm mức tiêu thụ năng lượng của máy nghiền. Xi măng được sản xuất bởi chất trợ nghiền có xu hướng nén và kết tụ thấp hơn, có lợi cho việc tải và dỡ xi măng và có thể làm giảm hiện tượng treo tường của kho xi măng.

With the exhaustion and limited exploitation of river sand resources, the contradiction between supply and demand of construction sand is becoming more and more fierce. The application of sea sand is a systematic engineering, which involves many links such as concrete raw materials, mix ratio, supervision of construction process, late maintenance and so on. In order to avoid the improper application of sea sand in engineering, it is necessary to strengthen supervision on all aspects of the use of sea sand. At the same time, more effective chlorine removal methods and application safeguards should be developed in order to make more effective use of sea sand resources.

The slag cement has the advantages of low hydration heat, high late strength, inhibition of alkali aggregate reaction, and resistance to sulfate corrosion, and has been applied in a large number of projects. When producing slag cement, due to the poor grindability of slag compared with clinker, the best active particle size is not achieved when co-grinding, and the single grinding will cause a lot of energy consumption, so it is used in the grinding process. Grinding aids to reduce grinding energy consumption and improve cement performance. Triethanolamine (TEA) and Triisopropanolamine (TIPA) are the main components of common grinding aids. They have strong polarity and can reduce the free energy of cement particles, prevent particle agglomeration and increase particles. The specific surface area also accelerates the hydration rate of clinker minerals. Most of the cement grinding aids are alcohol amines and polyols.

Alcohol amines mainly include ethanolamine, isopropanolamine, DEIPA, TIPA, etc., which are important basic chemical raw materials. The molecular structure of these substances contains alcohol and amine functional groups, and has the chemical properties of alcohols and amines. It exhibits very useful coordination in many synthetic applications, reacts with acids to form a cool, and reacts with hydrazine to form a amide-based compound. Because of their greater polarity, these molecules can be used as a raw material for surfactants, as well as fiber industrial refining agents, antistatic agents, dyeing aids, and fiber wetting agents. It can also be used in the preparation of synthetic detergents, cosmetics, lubricating oils, cutting oils, plasticizers, emulsifiers, etc.

Concrete admixtures are called admixtures. In the process of disposing and mixing concrete, it is necessary to add some products according to the city design requirements and test results to enhance or change the performance of concrete. This part of the added substances is called admixture, plus The use of the agent should be strictly controlled, and the total amount required should be 5% by weight of the regional cement. Admixture quality, type selection, dosage and ratio have a significant impact on the quality and performance of concrete. In the actual construction process, concrete processing, addition and use of admixtures should be carried out in strict accordance with the relevant standards set by the State.

Triisopropanolamine (TIPA) is a tertiary amine used in the cement industry as a grinding aid and in formulas of concrete. The addition of small amounts of TIPA can result in a significant increase in the strength of cement pastes at early and late ages [12]. Aggoun et al. [13] investigated the early strength and setting effects of TIPA-TEA-calcium nitrate mixture combinations in ordinary Portland cement and obtained necessary and promising results for both the setting and curing accelerator effects of the amine-calcium nitrate composition. The researcher found that TIPAs curing accelerator performance was higher than TEA regardless of cement type.

Alkanolamines are amines containing a single, double, or triple hydroxyalkyl group. They are frequently used as concrete admixtures and grinding aids. The action of triethanolamine (TEA) in the hydration of cement is not described explicitly in the literature since it has still not been concluded whether it is an accelerator or a retarder.

The water reducing agent is used for concrete mixing, which can change the gas content of the concrete, so that the gap ratio inside the concrete is greatly reduced. The effect of water reducer on the fluidity of concrete is usually reflected by the magnitude of the slump. When the proportion of water and cement used in concrete is constant, the degree of collapse of concrete can be greatly improved by adding a precipitant. And through the use of water reducing agents. The concrete setting time can be extended appropriately. However, it is necessary to properly control the amount of water reducing agent. Maintain reasonableness to avoid excessive increase in concrete that will not condense for a long time. By adding the scientific proportion of the water reducing agent, the performance and strength of the overall concrete structure can be improved, and the proportion of water cement in the concrete is reduced.