Special admixture for hydraulic structure permeable pointing mortar and its preparation and use method

Abstract

The invention relates to a special admixture for water-permeable pointing mortar of a hydraulic structure and a preparation and use method thereof. The special admixture is composed of the following components by weight: 20-23 parts of thickening component, 26-35 parts of quick-setting component, 34-40 parts of strengthening component, 5-7.5 parts of toughening component, water-reducing component Divide 2.5 to 5 parts, feed the above components into a powder mixer and mix for 5 to 10 minutes to prepare a special admixture. The method of using the above prepared special admixture is to mix it with ordinary Portland cement, fine bone Materials and water, according to the following proportions by weight, were mixed and stirred in a mixer for 5-10 minutes to prepare: 10-14 parts of ordinary Portland cement, 76.5-82 parts of fine aggregate, 1.5-2 parts of special admixture 6-8 parts of water. The invention can prevent the apron pointing mortar from falling off and structural damage, and ensure that the setting time of the pointing mortar material meets the quick-setting requirement.

Description

(1) Technical field: [0001] The invention relates to a special admixture for hydraulic structure permeable pointing mortar and a preparation and use method thereof, belonging to the technical field of production and application of civil engineering and hydraulic engineering materials. (2) Background technology [0002] The Qiantang River Old Sea Pond is a famous ancient water conservancy project, but because the project is located in a strong tidal estuary, the tide is high and the current is fast, especially the tidal surge of the Qiantang River, which has a strong impact. The sloping seawalls in this area have generally high foundations, weak anti-scouring structures, and frequent damage to the seawalls, which has become a long-standing engineering problem. Due to the poor construction environment of the seawall, there are two tides a day, and there is no general river to use the conditions of the dry season. The construction of cofferdams requires a huge amount of work, a...

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Problems solved by technology

[0005] For the apron structure, common impermeable mortar is generally used for pointing treatment at present. Because the pointing is impermeable, the bonding force between the pointing mortar and the block stone is poor, and the water pressure inside the embankment is relatively high, such as tidal water. When there is influx or heavy rain, the high internal water pressure will easily cause the joint mortar to fall off, resulting in damage to the apron structure

[0006] At present, permeable mortar is usually prepared by single-size fine aggregate, cement, reinforcing agent, etc., and then cured after pressure molding. The principle of water permeability is to use single-size aggregate to form a pore structure. A cement paste layer is formed on the surface of the fine aggregate, and the hardened cement paste binds the fine aggregate particles together to form a hardened permeable mortar, but this mortar cannot be used as a joint mortar because the water used in this type of permeable mortar The cement ratio is very small, the fluidity and viscosity of the cement slurry obtained by mixing are very poor, and the fine aggregate particles cannot be effectively bonded together, and its construction performance is obviously poor

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