Large-flow-state circumferential inverted arch thin-wall anti-crack concrete and preparation method thereof

Abstract

The invention discloses large-flow-state circumferential inverted arch thin-wall anti-crack concrete and a preparation method thereof. The concrete is prepared from the following components in parts by weight: 220 to 260 parts of ordinary Portland cement, 40 to 50 parts of fly ash, 80 to 100 parts of mineral powder, 20 to 35 parts of silica fume, 700 to 800 parts of coarse aggregate, 300 to 350 parts of modified ceramsite, 600 to 800 parts of fine aggregate, 30 to 50 parts of modified rubber particles, 1.5 to 2.7 parts of thickening agent, 7.2 to 8.9 parts of polycarboxylic acid water reducing agent, 1.6 to 3.1 parts of polypropylene fiber and 3 to 5 parts of expanding agent, and the water-binder ratio is 0.3 to 0.4. According to the large-flow-state circumferential inverted arch thin-wall anti-crack concrete, rigidity gradient change of a vertical structure is achieved, the anti-crack performance in a circumferential structure is good, and inverted arch disengaging and cracking under circumferential constraint are avoided.

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.