High-tenacity crack-control impervious fiber concrete

Abstract

The invention relates to a fiber concrete material belonging to the field of building materials. The fiber concrete material mainly contains cement, active mineral blending materials, aggregates, fibers and water and is characterized in that the active mineral blending materials adopt coal ash, siliceous dust, pelletization blast furnace slag and metakaolin; the fibers adopt polyvinyl alcohol fibers, polyethylene fibers and aromatic polyamide fibers; the maximum particle size of the aggregates is smaller than or equal to 0.5mm, and the ratio of the weight of the aggregates to the total weightof the cement and the active mineral blending materials is 1-70 percent; and the blending volume of the fibers accounts for 1.5-2.5 percent of the total volume of fiber concrete. The fiber concrete material has the advantages of high tenacity, higher deformation capability, tensile strength and bending strength, limit tension strain of 1.8-7.5 percent, tensile strength of 4-10MPa and bending strength of 10-20MPa, can control the width of a crack lower than 0.1mm, effectively enhance the integrity and the shock resistance of a structure and ensure the permeability resistance and the durabilityof the structure.

Description

technical field [0001] The invention belongs to the field of building materials and relates to a fiber concrete material. Background technique [0002] Concrete is the most widely used building material. Its main components include cement, active mineral admixtures, aggregates and water. It has the advantages of wide source of raw materials, simple process, and good fire performance. And low bending strength, small deformation capacity, poor toughness, easy to crack and difficult to control the crack width after cracking. The low toughness of concrete may lead to sudden catastrophic failure due to stress concentration at variable cross-section positions and joints of steel / concrete hybrid structures. cracking, resulting in a significant reduction in the seismic performance of the structure. Under the current economic and technical level, people usually think that the cracking of concrete is almost inevitable. Cracks, especially harmful cracks are not only unsightly, but al...

AI Technical Summary

Problems solved by technology

The fiber volume ratio of low fiber content concrete is usually less than 0.5% of the total volume of the concrete, such as commonly used polypropylene fiber concrete, the volume ratio of polypropylene fiber is usually 0.05% to 0.2%, mainly used to improve the early crack resistance of concrete performance, but polypropylene fiber has low strength (usually 300-600MPa) and low elastic modulus (3-10GPa), which has limited toughening effect on concrete and no obvious enhancement effect on bending and tensile strength. Provide sufficient bridging stress and the crack will propagate rapidly

The fiber volume ratio of medium fiber content concrete is usually 0.5% to 3%, such as steel fiber concrete with a fiber content of 1% to 2%, because steel fibers have high tensile strength (380 ~ 1400MPa) and High elastic modulus (150-210GPa), so the tensile and flexural strength of concrete can be significantly improved, and the corresponding flexural toughness, impact resistance and fatigue resistance are also significantly improved, but the deformation capacity has not been significantly improved. Its tensile strain capacity is on the order of 0.01% to 0.03%, and the material still cannot effectively control the crack width after cracking

The fiber volume ratio of high-fiber content concrete is usually 4% to 20%, such as mortar infiltrated steel fiber concrete (SIFCON), which has strain hardening and multi-slit cracking characteristics under tensile and bending loads, and its tensile strength, The flexural strength and toughness are greatly improved compared with concrete, but the fiber content as high as 4% to 20% doubles the cost of the material and requires a special pouring process to process and shape, thus limiting the popularization and application in engineering

[0004] The invention patent application with the application number 03129358.1 discloses a high-toughness hybrid fiber concrete and its preparation method. The technology adopts a medium fiber content, is based on ordinary concrete, and uses 0.1-0.2% of the volume of the concrete. The concrete volume percentage is 0.3-0.9% steel fiber hybrid reinforcement, although the strength and toughness of the material are significantly improved compared with concrete, but the deformation capacity and crack control ability are not significantly improved compared with ordinary medium-volume fiber concrete

The invention patent with the patent number ZL 200510046878.X discloses a cement-based composite material combined with short fibers and fiber woven mesh. Enhancement, which increases the construction procedure of materials and also increases the cost