Early-strength high-slump-retaining steam-curing-free concrete for PC components and preparation method of early-strength high-slump-retaining steam-curing-free concrete

Abstract

The invention discloses early-strength high-slump-retaining steam-curing-free concrete for PC components and a preparation method thereof, and the early-strength high-slump-retaining steam-curing-freeconcrete comprises the following components in parts by mass: 9-15 parts of cement, 20-30 parts of machine-made sand, 32-45 parts of gravel, 5-10 parts of fly ash, 3-5 parts of silica fume, 0.06-0.12part of sulfamate water reducer, 0.06-0.18 part of naphthalene water reducing agent, 0.002-0.01 part of defoamer and 7-12 parts of water. The early-strength high-slump-retaining steam-curing-free concrete for PC components can be prepared by premixing the raw materials, activating the aggregate, mixing the rubber materials and conducting quick stirring. The requirements that the PC component reaches 15MPa within 12h after natural curing, the slump time loss value of the concrete mixture within 1h is less than or equal to 20mm, and the slump time loss value of the concrete mixture within 3h isless than or equal to 50mm can be met, a PC factory can quickly, efficiently and stably conduct production, and remarkable economic and environmental benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to an early-strength, high-slump-retaining non-steam-curing concrete for PC components and a preparation method thereof. Background technique [0002] The traditional construction industry has many problems such as heavy environmental pollution, labor-intensive, low technical content, and unstable quality. It urgently needs new construction methods to realize the transformation and upgrading of the construction industry. Prefabricated buildings are the most effective way to realize the transformation and upgrading of my country's construction industry. Among them, the prefabricated concrete system occupies the main position of prefabricated buildings. Prefabricated concrete components (referred to as PC components) are a key part of prefabricated buildings. Compared with traditional cast-in-place concrete, PC components are produced by factory prefabrication a...

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Problems solved by technology

For example, the Chinese patent of a non-steam curing concrete prefabricated component and its forming method (CN108249846B) utilizes an inorganic-organic composite accelerator and an inorganic early-strength component to jointly promote the growth of early strength, but the inorganic early-strength salt component is mainly calcium salt , it is easy to cause the concrete slump to decrease significantly, and the slump-preserving performance is reduced. In addition, it will also cause surface sanding and carbonization to increase, and damage the durability of concrete. In addition, the organic early-strength components account for 15%-45%, which is too high The organic component of the organic component is easy to dissimilate the hydration product, and it will also reduce the later use strength of the main structure

A Chinese patent applied by Hubei University of Technology for a nano-crystal nucleus early strength agent (CN110963735A) for non-steamed prefabricated concrete components uses wet grinding technology and specific grinding aids to process waste plasma, cement, fly ash and mineral powder, etc. The material is ground to the micron and nanometer level to replace conventional cement and fly ash, so as to increase the reactivity and achieve early strength, but there are problems such as complex raw material preparation process and high amortization cost , and extremely fine raw materials are difficult to meet the needs of industrial production

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