Alkali-free liquid accelerator and preparation method and application thereof

Abstract

The invention discloses an alkali-free liquid accelerator, which is free of alkali in raw materials and preparation. The accelerator is composed of 30-80% of aluminum sulfate, 1-10% of hydroxy carboxylic acid, 4-15% of organic amine, 3-10% of polyhydric alcohols, 1-5% of inorganic acid and the balance of water. The accelerator disclosed by the invention is high in early strength, low in long-term strength loss, good in caking property and low in resilience value; as a result, environment-friendly no-pollution construction can be realized; the synthetic process of the accelerate is simple and moderate in reaction conditions; and therefore, the accelerate is an excellent-performance alkali-free liquid accelerator.

Description

technical field [0001] The invention relates to a concrete quick-setting agent for cement-based materials, in particular to a preparation method of a high-performance alkali-free liquid quick-setting agent for shotcrete, and belongs to the field of building materials. Background technique [0002] Accelerator is an admixture that can quickly set and harden concrete. It is widely used in underground engineering, mining engineering, embankment slope reinforcement, and emergency rescue projects. It is one of the indispensable and important admixtures for shotcrete. [0003] The principle of action of the accelerator is that adding it to the cement slurry will promote the hydration reaction of minerals such as tricalcium aluminate and tricalcium silicate in the cement, and form calcium aluminate hydrate, ettringite, and hydration in a short time. Hydration products such as calcium silicate make the cement paste harden and coagulate rapidly. Traditional quick-setting agents are ...

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Problems solved by technology

Traditional quick-setting agents are mostly in the form of powder, which is not convenient for construction operation and measurement. The construction dust is large, and the high-alkaline dust will cause great harm to the health of construction workers; although ordinary liquid quick-setting agents can be accurately measured, it can ensure that the concrete Quality stability, avoiding dust pollution and other hazards, but because its main mechanism is to use high alkali to turn gypsum in cement into sodium sulfate, losing the retarding effect, thereby accelerating cement hydration to achieve quick-setting effect, on the one hand, high alkali It will cause harm to the health of construction workers. On the other hand, the high alkali content can easily lead to alkali-aggregate reaction in concrete, and the strength will shrink severely in the later stage. Due to the extensive use of alkaline substances, the strength of concrete in the later stage will be 30% or even greater. The reduction will affect its service life

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