A vibration-free high-strength self-compacting concrete that can be pumped at an ultra-high height of 620 meters and its preparation method

Abstract

The invention provides vibrating-free, high-strength and self-compacting concrete capable of being pumped for a super-large height larger than 620 meters and a preparation method of the concrete. The concrete is prepared from components of raw materials in percentage by mass as follows: 14%-15% of cement, 3.5%-4.5% of mineral powder, 2.5%-3.5% of ceramic polishing powder, 1%-2% of superfine fly ash, 70% of aggregate, 0.4%-0.6% of a polycarboxylic acid additive and 6.4%-6.6% of mixing water, wherein the aggregate comprises sand and stones, and the sand ratio ranges from 44% to 50%; sand comprises medium sand and fine sand, the stones comprise large stones and small stones, the fineness modulus of the medium sand is 2.4-2.6, and the fineness modulus of the fine sand is 1.9-2.1; the diameter of each large stone is 10-20 mm, and the diameter of each small stone is 5-10 mm. The high-strength concrete can be prepared with a conventional method. The extended degree of the high-strength and self-compacting concrete discharged out of a machine is higher than or equal to 700 mm, T500 is lower than or equal to 4 s, PA is lower than or equal to 20 mm, and SR is lower than or equal to 15%; the concrete is soft and loose and has medium viscosity and excellent self-compaction performance; the loss of the work performance of the concrete pumped for a 621-meter super-large height is as follows: the extended degree is lower than or equal to 10 mm, T50 is lower than or equal to 1 s, PA is lower than or equal to 10 mm, and SR is lower than or equal to 5%; the self-compaction performance at a pumping outlet is realized, and construction of concrete with a complicated structure can be realized without vibration.

Description

technical field [0001] The invention belongs to the technical field of engineering building materials, in particular to a vibration-free high-strength self-compacting concrete capable of being pumped at an ultra-high height of 620 meters and a preparation method thereof. Background technique [0002] As a product of the combination of industrialization and urbanization, skyscrapers originated in the United States and have now spread all over the world. Skyscrapers are generally considered to be the ultimate symbol of urban development and urban economic power, and they have significant positive significance in promoting intensive use of land, forming urban agglomeration effects, enhancing the image of urban landmarks, expanding the vertical and horizontal space of the city, and promoting the interaction of spatial landscapes. At the same time, since the beginning of the new century, the height of the tallest building in the world has been continuously refreshed, and the aver...

AI Technical Summary

Problems solved by technology

However, after the pumping height of concrete exceeds 400 meters, it is easy to cause segregation, bleeding, and separation of pulp and bone in concrete with the increase of pumping pressure, resulting in aggregate accumulation and pipe blockage, resulting in huge economic losses. loss

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