Low-resilience, early-strength and high-strength wet-spraying concrete and application thereof

Abstract

The invention relates to the field of building materials and in particular provides low-resilience, early-strength and high-strength wet-spraying concrete and application thereof. The low-resilience,early-strength and high-strength wet-spraying concrete is prepared from the following raw materials in parts by weight: 380 to 500 parts of cement, 800 to 1000 parts of sand, 650 to 800 parts of crushed stone, 10 to 30 parts of a setting accelerator, 160 to 200 parts of water, 20 to 30 parts of a high-strength ultra-micro additive and 40 to 50 parts of fly ash. According to the low-resilience, early-strength and high-strength wet-spraying concrete prepared by the invention, the binding force is greatly improved and the resilience rate of the concrete is reduced; the concrete can be normally sprayed in a water-rich region and a result reaches the advanced level in China; the low-resilience, early-strength and high-strength wet-spraying concrete can be directly applied to primary supportingconstruction of tunnels and a novel technical way is explored for the primary supporting construction of the tunnels.

Description

technical field [0001] The invention relates to the field of building materials, in particular to low-rebound early-high-strength wet shotcrete and its application. Background technique [0002] Shotcrete is the most important force-bearing structure for primary support. Its early strength (within 24 hours), cohesive force, slump retention, and workability have a great impact on the safety, quality, cost, and work efficiency of tunnel construction. Later strength and durability are of great significance to the quality of tunnel operation. According to the status quo of domestic tunnel construction and the "Regulations on the Administration of Quality and Safety Red Lines of Railway Construction Projects", the strength of shotcrete core sampling and testing for the initial support of tunnels in various industries has become the norm. The consumption rate is generally 250% to 300% of the design volume, the excess consumption rate is 150% to 200%, the consumption rate in the w...

AI Technical Summary

Problems solved by technology

However, due to the late start of wet spraying concrete in my country, the low technical level, and the poor quality of domestic raw materials, the non-alkali accelerator and the immature technology of wet spraying manipulators, the sprayed concrete has high comprehensive costs, poor workability, and poor slump retention. The dependence on hand and wet spraying machines is high, sprayed concrete has been at a low level from design to construction, and the development of tunnel technology is facing a huge technical bottleneck

[0003] With the continuous improvement of domestic machinery manufacturing capabilities, large-scale manipulators have been popularized and widely used, and the cost performance of wet-spraying manipulators has continued to increase. However, due to the immature technology of domestic equipment and the fierce competition of homogeneous products, the equipment performance has not made a qualitative leap after all. There is an urgent need for a fundamental breakthrough in the shotcrete mix ratio technology. Only by improving the performance of the concrete itself and reducing the requirements for shotcrete on equipment and personnel can the real needs of tunnel construction be met.

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