High-toughness polypropylene fiber reinforced cement-based composite material and preparation method thereof

Abstract

The invention relates to a high-toughness polypropylene fiber reinforced cement-based composite material and a preparation method thereof, and provides the high-toughness polypropylene fiber reinforced cement-based composite material with the advantages of easily-obtained raw materials, low cost, low requirements on processing technology and an operating environment, stable mechanical property and high toughness and the preparation method thereof. The high-toughness polypropylene fiber reinforced cement-based composite material comprises the following components in percentage by weight: 16.7 to 52.5 percent of cement, 13.1 to 39 percent of fly ash, 22.2 to 26.3 percent of silica sand, 6.6 to 16.7 percent of water, 1.3 to 2.8 percent of water reducing agent, 0.03 to 0.1 percent of thickening agent and 1.47 to 2.5 percent of polypropylene fiber. The preparation comprises the following steps of: adding the cement, the fly ash and the silica sand into an agitating vessel of an agitator toperform dry mixing until all base materials are mixed uniformly; adding the water into the base materials to agitate until uniform pasty slurry with high flowability is formed; adding the water reducing agent and the thickening agent; and then continuously agitating until the fiber is dispersed uniformly.

Description

Technical field: [0001] The invention relates to a fiber-reinforced cement-based composite material for building structures, road and bridge water conservancy projects and a preparation method thereof, in particular to a strong and tough polypropylene fiber-reinforced cement-based composite material and a preparation method thereof. Background technique: [0002] A large number of experimental studies and engineering practices in modern times have shown that cracking of concrete structures is almost inevitable. Under the current economic and technical level, the cracks of concrete are generally controlled within the allowable range of harmful levels. In order to reduce or even eliminate early shrinkage cracks of concrete, reduce load cracks and improve material toughness, fiber reinforced concrete materials have been widely used in recent years and have achieved good results. However, these fiber reinforced concretes still cannot effectively control the development of crack ...

AI Technical Summary

Problems solved by technology

Although the polyvinyl alcohol fiber-reinforced cement-based composite material provided in the above-mentioned preparation scheme has obtained strain hardening phenomenon and composite cracking effect, there are the following deficiencies: 1. High requirements for equipment and working environment; 2. The price of polyvinyl alcohol fiber is expensive, resulting in high cost of finished products; 3. After hardening of polyvinyl alcohol fiber reinforced cement-based composite material, the stability of mechanical properties is not high; 4. Polyethylene Alcohol fiber is a hydrophilic material, and the interface binding force with the cement matrix is ​​very strong, resulting in chemical binding energy. When subjected to an external load, the polyvinyl alcohol fiber is easily broken and rarely slips due to pulling. Therefore, the toughness and ultimate tensile strain of PVA fiber concrete are not good enough, and it is necessary to carry out surface treatment on PVA fiber before it can become strong and tough fiber concrete. Kurrary company in Japan usually treats PVA fiber by oiling its surface, so that It produces a water-repelling effect and reduces its bonding force with the cement matrix. In this way, when the PVA polyvinyl alcohol fiber concrete is subjected to external force, the PVA fiber will be broken after slipping, so that the fiber concrete will undergo sufficient deformation. However, the PVA fiber-reinforced cement composite made of PVA fibers is very sensitive to the loading strain rate. If the loading rate is too large, the material will show a certain degree of toughness decline.

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