A kind of low-shrinkage self-compacting concrete for steel shell immersed tube, its preparation method and application

Abstract

Low-shrinkage self-compacting concrete used for steel-shell immersed tubes is disclosed. Raw materials of the concrete include cement, an aluminum stabilizing compacting agent, ore powder, limestone powder, river sand, broken stone, water and a water reducing agent. According to performance control indexes of a mixture of the concrete, the slump extension is 600-700 mm, V-shaped funnel efflux time is 5-15 s, the H2 / H1 value tested by an L-shaped instrument is not less than 0.9, a [delta]h value tested by a U-shaped instrument is not more than 30 mm, the unit weight is 2300-2400 kg / m<3>, and the gas content is not more than 4%. The concrete has good fluidity, fallibility and segregation resistance. Compared with traditional self-compacting concrete, the low-shrinkage self-compacting concrete has a low gel material using amount and low shrinkage, has good adaptability to steel-shell immersed tube structures, has a strength grade of C50, and is suitable for use as self-compacting concrete having good working properties, mechanical properties and volume stability for steel-shell immersed tunnels.

Description

technical field

[0001] The invention belongs to the technical field of concrete, in particular to the technical field of self-compacting concrete. Background technique

[0002] From the structural point of view, immersed tube tunnels mainly include reinforced concrete immersed tubes and steel shell concrete immersed tubes. The steel shell concrete immersed tube joint adopts the structural form of two-layer steel shell filled with concrete, and the pipe joint is composed of multiple cells. figure 1 Shown is a schematic diagram of steel shell concrete immersed tube joints, figure 2 Shown is a schematic diagram of the concrete pouring of the pipe section grid. Compared with reinforced concrete immersed tubes, steel shell concrete immersed tubes have the following advantages: lower cost, more convenient construction, shorter construction period, relatively smaller structure scale, stronger bearing capacity, better anti-settlement and seismic adaptability, less There are crac...

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