Polyurethane/polyurea composite protective layer and preparation method thereof, and application of polyurethane/polyurea composite protective layer in concrete shielding

Abstract

The invention discloses a polyurethane / polyurea composite protective layer and a preparation method thereof, and application of the polyurethane / polyurea composite protective layer in concrete shielding. The polyurethane / polyurea composite protective layer comprises a concrete base layer, a polyurethane elastic layer and a polyurea layer from bottom to top. The preparation method comprises the following steps: treating the surface of the concrete, and forming the polyurethane elastic layer by a multiple brushing or spraying method until reaching the designed thickness; and after the surface of the last brushing or spraying polyurethane layer becomes dry, spraying at least one polyurea layer to form the polyurethane / polyurea composite protective layer. The invention can be used for combined shielding of concrete surfaces in track traffic, parking lots, airports, roofs, road surfaces, playgrounds, sewage treatment plants, harbors, navigation locks, waterways, bridges, tubular piles and the like. The invention combines the elasticity, toughness and low price of the polyurethane with the shock resistance, wear resistance, corrosion resistance, aging resistance and other characteristics of the spraying polyurea to obtain the composite protective layer which has the advantages of excellent water resistance, excellent corrosion resistance, excellent shock resistance, high cost performance and high construction speed.

Description

technical field [0001] The invention relates to the preparation of a composite protective layer and its new application in concrete protection, in particular to the preparation of a polyurethane and polyurea composite protective layer and its application in concrete surface protection. Background technique [0002] Concrete is an indispensable building material with the largest amount of consumption in architecture and engineering construction, and plays an important role in the operation safety of the entire building or project. The reasons for the poor durability of concrete are complex and diverse, which can be divided into physical, chemical and mechanical effects. Concrete deterioration caused by physical effects includes cracks caused by temperature changes, freeze-thaw cycles, ice salt erosion of concrete, etc.; chemical corrosion mainly includes steel corrosion caused by external aggressive ions (Cl - ), sulfate attack (SO 4 2- ), carbonization (CO 2 ), etc.; mec...

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Problems solved by technology

However, its high temperature resistance is poor, and it is easy to stick back at high temperature, resulting in a decrease in stain resistance.

[0006] Germany Wacker Chemie Co., Ltd. has developed a new type of silane cream product. This material is simple in construction, with little loss of active components, and it has good environmental factors such as ultraviolet radiation, heat, corrosive chemicals and microorganisms. Resistance, but the polycondensation reaction of siloxane is slow at room temperature, and the impermeability is poor

[0007] Polyurea elastomer (SPUA) technology is a new type of solvent-free and pollution-free new material and construction technology developed in foreign countries in the past 20 years. It has fast curing, excellent physical and chemical properties, and excellent thermal stability. However, due to the polyurea material The reaction speed is fast, it cannot penetrate well on the base layer, and it is easy to peel off and lose its protective effect. At the same time, it is relatively expensive to use polyurea materials as protective materials, which limits the application of polyurea materials to a certain extent.

[0008] In short, the current concrete surface protection materials have their own advantages and disadvantages, and they cannot protect concrete materials well. On the other hand, these materials only perform waterproof treatment on the concrete surface, and cannot achieve the purpose of elastic shock absorption, so the external impact force is relatively large. can not protect the concrete structure well from damage

[0009] At present, high molecular polymer materials are mainly used in the waterproofing of tunnels, railways, buildings, etc., but there are few applications that combine polymer waterproofing, anticorrosion and elastic protection. Corresponding defects, such as polyurethane coatings have good adhesion and water resistance but poor wear resistance, and the construction period is long. Polyurea waterproof materials have excellent performance, good wear resistance, and fast curing, but poor adhesion and are easy to repair Layer peeling, high cost when thick coating

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