Plastic anti-crack modified fiber of cement-based material and prepn. process

Abstract

This invention is attributed to the field of materials science and engineering and concretely speaking, relates to a kind of modified fibers for preventing plastic cracking of cement-based materials (such as cement paste, mortar, concrete their composites), which comprises organic synthetic fibers, inorganic fibers or organic-inorganic hybrid fibers and modifiers. The modified fibers in this invention perform significant prevention from plastic shrinkage cracking of cement-based materials from their molding to complete solidification, and over 90% plastic cracking can be reduced by doping with the fibers compared to undoped ones. They also have an effect of reducing 30~50% more plastic cracking than unmodified fibers. This invention can be widely applied in cement-based materials engineering, such as cement-concrete roads, bridge decks, grounds, slope protection, dams, etc, so as promote project quality.

Description

technical field [0001] The invention belongs to the field of material science and engineering science and technology, and particularly relates to a modified fiber for preventing plastic shrinkage and cracking of cement-based materials (cement paste, mortar, concrete and composite materials thereof). Background technique [0002] Concrete is one of the largest and most widely used man-made building materials in the world. At present, my country's annual cement output has reached 860 million tons, and the annual concrete consumption has reached 2 billion cubic meters. For quite a long period of time in the future, concrete will still be the main building material of modern engineering construction in our country. Moreover, because it has the advantages of wide application range, cheap price, easy casting, relatively durable, and can effectively use some industrial solid waste to make energy-saving and environmentally friendly building materials, it plays an irreplaceable role...

AI Technical Summary

Problems solved by technology

[0003] However, concrete also has the disadvantages of low tensile strength, small ultimate tensile strain, poor impact strength, especially high brittleness, and concrete cracking due to plastic shrinkage and drying loss before the cement hardens.

Among them, the defect of plastic shrinkage and cracking of cement concrete has a great impact on the quality of concrete engineering, especially for high-strength concrete, which may cause rework during the construction stage because it directly affects the appearance quality of the project, or bring shrinkage cracks in the plastic stage into the engineering use stage. Due to this "congenital" defect of concrete, its impermeability, frost resistance, chemical medium corrosion resistance, steel corrosion resistance and other properties are affected, resulting in a greatly shortened service life of concrete and a substantial increase in concrete maintenance and repair costs