Ultrahigh-property cement-based material with low shrinkage and high toughness and preparation method thereof

Abstract

The invention discloses an ultrahigh-property cement-based material with low shrinkage and high toughness and a preparation method thereof. The ultrahigh-property cement-based material with low shrinkage and high toughness is prepared from the main components in parts by weight: 590-680 parts of ordinary Portland cement, 280-305 parts of fine sinking beads, 90-115 parts of silica fume, 1050-2000 parts of river sand, 29-67 parts of expanding agent, 180-240 parts of steel fiber, 18-23 parts of water reducing agent and 155-190 parts of water. The ultrahigh-property cement-based material and the preparation method disclosed by the invention have the beneficial effects that the preparation process is simple, and the ultrahigh-property cement-based material with excellent properties in all the aspects of fluidity, strength and the like can be prepared by adopting a conventional cement mortar planetary stirring machine; in addition, on the basis of meeting the basic specification requirementsof all admixtures and by common action of the raw materials, the use amount of cementitious materials can be obviously saved. The obtained ultrahigh-property cement-based material has the advantagesof low use amount of the cementitious materials, simple forming process, excellent working property, low comprehensive cost and less early shrinkage, so that the application prospect is wide.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a low-shrinkage, high-toughness, ultra-high-performance cement-based material and a preparation method thereof. Background technique [0002] With the advancement of social civilization and the continuous development of various new technologies and industrial machinery, concrete in the traditional sense with low strength and single function has become unsustainable to meet the needs of the rapid development of modern construction projects. Concrete The performance also puts forward higher requirements. At present, the development of concrete is aimed at ultra-high strength and high durability, and is developed in the direction of composite materials that combine the advantages of other building materials. The name of UHPC (Ultra High Performance Concrete, UHPC) was formed in this century. Its compressive strength is greater than 150MPa, and its tensile strength is g...

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Problems solved by technology

[0003] In order to obtain higher strength, UHPC has a higher content of cementitious materials, and its early shrinkage is more serious than that of ordinary concrete, especially in the early plastic stage of pouring molding. The cement is in the stage of rapid hydration reaction. The chemical composition and microstructure of the concrete The coupling effect of chemical shrinkage and early self-drying shrinkage caused by the change of internal capillary structure will lead to a large early plastic shrinkage value of UHPC, and the concrete structure will crack due to shrinkage, which will affect the safety of the structure. And durability poses a threat, and in order to enhance the toughness of UHPC and ensure its good crack resistance, the currently commonly used measure is to add steel fibers. However, in the case of extremely low water-binder ratio, adding steel fibers will seriously affect Therefore, it is imperative to design and prepare an ultra-high performance cement-based material with high toughness and low shrinkage

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