Special sprayed concrete material for tunnel high ground temperature and dry heat environment

A shotcrete, high ground temperature technology, applied in the field of concrete, can solve the problems of increased concrete rebound, loss of cohesion, debonding and cracking, etc.

Active Publication Date: 2021-03-09
SOUTHWEST JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Ordinary shotcrete is mainly composed of cement, ordinary sandstone and quick-setting agent. In the hot and dry environment of high ground temperature, the springback of ordinary shotcrete increases significantly, the cohesion loss is serious, and even debonding and cracking occur. The failure of protective effect has become a key factor affecting the performance of shotcrete with high ground temperature, and there is no effective solution so far

Method used

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  • Special sprayed concrete material for tunnel high ground temperature and dry heat environment
  • Special sprayed concrete material for tunnel high ground temperature and dry heat environment
  • Special sprayed concrete material for tunnel high ground temperature and dry heat environment

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Example 1: 100°C high ground temperature and dry heat environment

[0016] Application of main raw materials and main proportion parameters of concrete per cubic meter:

[0017] (1) The total amount of cementitious materials is 420kg (83% ordinary Portland cement, 15% sulphoaluminate cement, 2% nano-silicon oxide);

[0018] (2) 775kg of stones;

[0019] (3) Steel fiber 45kg;

[0020] (4) The amount of shrinkage reducing agent is 5%;

[0021] (5) The dosage of water reducer JX-GBNHy2 high-performance polycarboxylic acid is 1.2%;

[0022] (6) Accelerator JX-E 3 Liquid dosage 5%;

[0023] (7) The glue-bone ratio is 1:4.1; the sand rate is 0.55; the water-binder ratio is 0.45.

[0024] The specific mix ratio is shown in Table 1 below (unit: kg).

[0025] Table 1 Application of main raw materials per cubic meter of concrete in Example 1

[0026]

[0027] Technical index tests include: slump, compressive strength, split tensile strength, bond strength and rebound r...

Embodiment 2

[0031] Example 2: Dry and hot environment with high ground temperature of 80°C

[0032] Application of main raw materials and main proportion parameters of concrete per cubic meter:

[0033] (1) The total amount of cementitious materials is 400kg (88% ordinary Portland cement, 11% sulphoaluminate cement, 1% nano-silicon oxide);

[0034] (2) 758kg of stones;

[0035] (3) Steel fiber 40kg;

[0036] (4) The amount of shrinkage reducing agent is 5%;

[0037] (5) The dosage of water reducer JX-GBNHy2 high-performance polycarboxylic acid is 1.2%;

[0038] (6) Accelerator JX-E 3 Liquid dosage 5%;

[0039] (7) The glue-bone ratio is 1:4.3; the sand ratio is 0.56; the water-binder ratio is 0.47.

[0040] The specific mix ratio is shown in the following table 2 (unit: kg).

[0041] Table 3 Application of main raw materials per cubic meter of concrete in Example 2

[0042]

[0043]Technical index tests include: slump, compressive strength, split tensile strength, bond strength...

Embodiment 3

[0047] Example 3: Dry and hot environment with high ground temperature of 60°C

[0048] (1) The total amount of cementitious materials is 400kg (89% ordinary Portland cement, 10% sulphoaluminate cement, 1% nano-silicon oxide);

[0049] (2) 758kg of stones;

[0050] (3) Steel fiber 39kg;

[0051] (4) The amount of shrinkage reducing agent is 5%;

[0052] (5) The dosage of water reducer JX-GBNHy2 high-performance polycarboxylic acid is 1.1%;

[0053] (6) Accelerator JX-E 3 Liquid dosage 5%;

[0054] (7) The glue-bone ratio is 1:4.3; the sand rate is 0.56; the water-binder ratio is 0.48.

[0055] The specific matching ratio is as follows (unit: kg)

[0056] Table 5 Application of main raw materials per cubic meter of concrete in Example 3

[0057]

[0058] Technical index tests include: slump, compressive strength, split tensile strength, bond strength and rebound rate. The comparison results of the concrete test results of Example 3 and the benchmark working condition...

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Abstract

The invention discloses a special shotcrete material for tunnels with high ground temperature and dry heat environment. The total amount of cementitious materials per cubic meter of concrete is 400-420kg; the cementitious materials contain 83%-89% of ordinary Portland cement by weight percentage , sulphoaluminate cement 10% to 15%, nano-silica 1% to 2%; steel fiber is added according to the volume ratio of 0.4% to 0.6%; shrinkage reducing agent is added according to 5% of the weight of the cementitious material; concrete preparation speed The gelling agent is added according to 3-5% of the weight of the gelling material; the gel-bone ratio is 1:4.0-1:4.5; the water-binder ratio is not greater than 0.50. The special shotcrete of the present invention has higher compressive strength and tensile strength than ordinary shotcrete with the same strength grade under the synergistic effect of materials in a certain proportioning ratio. Depending on the temperature of the dry and hot environment, the bonding strength is 2 to 4 times that of ordinary shotcrete, and the rebound rate is only 1 / 3 to 1 / 2 of that of ordinary shotcrete.

Description

[0001] Technical field [0002] The technology of the invention belongs to the field of concrete, and in particular relates to a special sprayed concrete material for tunnels with high ground temperature and dry heat environment. Background technique [0003] "Multiple, long, large, and deep", that is, large number, large length, large section, and large buried depth have become the development trend of tunnel engineering in my country. Deep buried long tunnels play an irreplaceable role in overcoming terrain obstacles such as mountains and valleys, shortening spatial distances, and improving the operation quality of land transportation projects. With the advancement of design theory and construction technology, more deep-buried long tunnels will be built in fields such as railways, highways, hydropower, inter-basin water diversion, and mineral resources, and the accompanying problem of high ground temperature has become increasingly prominent. High ground temperature in tunn...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B28/06
CPCC04B28/06C04B2111/00008C04B2111/00155C04B2201/50C04B7/02C04B14/06C04B14/48C04B2103/302C04B2103/0068C04B2103/12C04B14/068C04B18/12
Inventor 崔圣爱刘品许雪峰符飞郭晨李固华李福海
Owner SOUTHWEST JIAOTONG UNIV
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