A kind of high-strength shotcrete for high ground temperature tunnel and its preparation method

A technology of sprayed concrete and high ground temperature, applied in the field of concrete, can solve the problems of high interface bonding strength, good impermeability, low thermal conductivity, etc., and achieve the effects of alleviating high temperature shedding, uniform coagulation hydration, and reduced moisture migration

Active Publication Date: 2020-11-27
CHANGAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The resulting concrete has the characteristics of low thermal conductivity, good impermeability, high interface bonding strength, and small loss of strength in the later stage, which greatly improves the strength of the concrete in the later stage after spraying, and solves the cracking problem of high-temperature concrete

Method used

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  • A kind of high-strength shotcrete for high ground temperature tunnel and its preparation method
  • A kind of high-strength shotcrete for high ground temperature tunnel and its preparation method
  • A kind of high-strength shotcrete for high ground temperature tunnel and its preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0033] A method for preparing high-strength shotcrete for tunnels with high ground temperature, the raw material ratio is as follows:

[0034] 1m 3 The quality of raw materials contained are: cement 350kg, fly ash 75kg, slag powder 75kg, gravel 483kg, sand 650kg, water 225kg, vitrified microspheres 100kg, PVA fiber 1kg, steel fiber 40kg, modified rubber 31.5kg, Water agent 4kg, accelerator 25kg.

[0035] The preparation method is implemented according to the following steps:

[0036] Step 1: Add 6kg of sodium silicate into 50L of warm water at a temperature of 40°C to fully dissolve to obtain a sodium silicate sol; then add 94kg of rubber powder to the sodium silicate sol, stir and mix for 2 hours, and let it stand for 2 hours to obtain the modified product rubber;

[0037] Step 2: Stir and mix cement, slag powder, fly ash, sand, coarse aggregate, vitrified beads, water reducing agent and water to obtain a base material; then add modified rubber, steel fiber, and PVA fiber ...

Embodiment 2

[0040] A method for preparing high-strength shotcrete for tunnels with high ground temperature, the raw material ratio is as follows:

[0041] 1m 3 The quality of raw materials contained are: cement 315kg, fly ash 67.5kg, slag powder 67.5kg, gravel 480kg, sand 630kg, water 202.5kg, vitrified microspheres 100kg, PVA fiber 1kg, steel fiber 35kg, modified rubber 30kg , 3.6kg of water reducer, 22.5kg of accelerator.

[0042] The preparation method is implemented according to the following steps:

[0043] Step 1: Add 6kg of sodium silicate into 50L of warm water at a temperature of 40°C to fully dissolve to obtain a sodium silicate sol; then add 94kg of rubber powder to the sodium silicate sol, stir and mix for 2 hours, and let it stand for 2 hours to obtain the modified product rubber;

[0044] Step 2: Stir and mix cement, slag powder, fly ash, sand, coarse aggregate, vitrified beads, water reducing agent and water to obtain base material; then add modified rubber, steel fiber ...

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Abstract

The invention discloses a high strength sprayed concrete for high ground temperature tunnels and a preparation method thereof. The concrete comprises following raw materials: cement, fly ash, slag powder, sand, coarse aggregate, glass beads, PVA fibers, steel fibers, modified rubber, a water reducer, a setting accelerator, and water. Low melting point water-soluble PVA fibers are adopted, after concrete reaches the melting point of the PVA fibers, fibers are melted, tunnels are formed, thus water steam in the concrete can be conveniently dissipated through the tunnels, the steam pressure in the concrete is reduced, the risk of bursting is reduced, at the same time, the melted water-soluble PVA fibers can largely enhance the inner cohesive force of concrete, and the cracking of a cement face is avoided. Through the cooperation of all raw materials, the prepared concrete has the characteristics of low heat conductivity coefficient, good anti-permeability, high interfacial bond strength,and little long-term strength loss. The long-term strength of concrete after spraying is largely improved. The cracking of high ground temperature concrete is avoided.

Description

technical field [0001] The invention belongs to the technical field of concrete, and in particular relates to a high-strength shotcrete for high ground temperature tunnels and a preparation method thereof. Background technique [0002] After the excavation of high ground temperature tunnels, due to the high temperature of the excavated rock surface (above 80°C), the physical properties and failure modes of concrete after shotcreting change, often resulting in low concrete strength, high rebound rate, and uneven strength distribution. Cracking and other diseases. [0003] Due to the migration of water molecules during the condensation process of high-temperature concrete, the internal compactness of the concrete is uneven, and under different normal stresses and temperatures, concrete cracks along the cemented surface and near the cemented surface appear. Cracking along the bonded surface is the most common type of concrete failure. Contents of the invention [0004] In o...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B28/04C04B111/34C04B111/76
CPCC04B28/04C04B2111/00155C04B2111/00724C04B2111/343C04B2111/763C04B2201/10C04B2201/32C04B2201/50C04B18/08C04B18/141C04B14/02C04B14/06C04B14/24C04B14/48C04B22/00C04B18/22C04B16/0641C04B2103/302C04B2103/12
Inventor 田威张旭东张丽肖煜强余宸
Owner CHANGAN UNIV
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