A kind of anti-cracking concrete with large fluid state annular inverted arch thin-wall and its preparation method

Abstract

The invention discloses a thin-wall anti-cracking concrete with a large flow state circular inverted arch and a preparation method thereof. The concrete includes the following components in parts by weight: 220-260 parts of ordinary portland cement, 40-50 parts of fly ash, 80-100 parts of mineral powder, 20-35 parts of silica fume, 700-800 parts of coarse Aggregate, 300‑350 parts of modified ceramsite, 600‑800 parts of fine aggregate, 30‑50 parts of modified rubber particles, 1.5‑2.7 parts of thickener, 7.2‑8.9 parts of polycarboxylate water reducer, 1.6‑ 3.1 parts of polypropylene fiber, 3-5 parts of expansion agent, water-binder ratio of 0.3-0.4. The thin-wall anti-cracking concrete for large-flow circular inverted arches provided by the invention realizes the stiffness gradient change of the vertical structure, has good crack resistance performance in the annular structure, and avoids voiding of the inverted arches and cracking under annular constraints.

Description

technical field [0001] The invention belongs to the field of concrete, and in particular relates to a large-fluid annular inverted arch thin-wall crack-resistant concrete and a preparation method thereof. Background technique [0002] In engineering projects with arch structures such as tunnels, cast-in-situ concrete with impermeability is often used for the secondary lining structure. Usually, the thickness of this structural layer is between 20-40cm, and the size is small. Due to the constraints of prefabricated segments Due to the action of the concrete and the settlement of the concrete, problems such as cracking and voiding of the vault often occur in the arched structure. [0003] At present, measures such as adding expansion agent, fiber and low-heat and low-shrinkage concrete mix ratio are commonly used to prevent the above problems in vault concrete, but they still cannot solve the concrete cracking under the condition of circumferential constraints, uneven shrinkag...

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Problems solved by technology

[0003] At present, measures such as adding expansion agents, fibers, and low-heat, low-shrinkage concrete mix ratios are commonly used to prevent the above-mentioned problems in vault concrete, but they still cannot solve the concrete cracking under the condition of circumferential constraints, uneven shrinkage, and multi-directional stress.