CN-121974651-A - Shrinkage-free high-ductility waterproof repair mortar and preparation method thereof

CN121974651ACN 121974651 ACN121974651 ACN 121974651ACN-121974651-A

Abstract

The invention relates to the technical field of waterproof mortar, in particular to shrinkage-free high-ductility waterproof repair mortar and a preparation method thereof. The shrinkage-free high-ductility waterproof repair mortar comprises a high-ductility functional system and a controllable early-strength system, wherein the high-ductility functional system comprises modified sisal fibers, anhydrous calcium sulfate, an ethylene-vinyl acetate copolymer, an amorphous active silicon material, a defoaming agent, lithium carbonate, cellulose ether, a thixotropic agent, L-tartaric acid and sodium gluconate, and the controllable early-strength system comprises ordinary portland cement, rapid hardening sulphoaluminate cement, 20-40-mesh river sand and 40-70-mesh river sand. The high-ductility functional system and the controllable early-strength system form the high-ductility shrinkage-free waterproof repair mortar through a specific preparation mode, the controllable early-strength system can quickly repair a damaged structure, can be effectively bonded in unfavorable environments such as humidity, vertical surfaces and the like, can keep the system crack and not break when being damaged by external force, and can effectively stop leakage.

Inventors

LI QUANMING
XIE KAI
WU WENXUAN
GENG CHAO
CHEN CHENG
WANG YUKAI
LIAO MINGRU
ZHANG XIAOPING
ZHANG MEICONG
LI WEI
ZHANG HONG

Assignees

北方工业大学
武汉源锦建材科技有限公司
中国市政工程中南设计研究总院有限公司

Dates

Publication Date: 20260505
Application Date: 20251225

Claims (10)

1. The shrinkage-free high-ductility waterproof repair mortar is characterized by comprising a high-ductility functional system and a controllable early-strength system, wherein the high-ductility functional system comprises modified sisal fibers, anhydrous calcium sulfate, ethylene-vinyl acetate copolymer, amorphous active silicon materials, defoamers, lithium carbonate, cellulose ether, thixotropic agents, levorotatory tartaric acid and sodium gluconate, the controllable early-strength system comprises ordinary portland cement, rapid hardening sulphoaluminate cement, 20-40 mesh river sand and 40-70 mesh river sand, and the mass ratio of the high-ductility functional system to the controllable early-strength system is 1-10:70-100.
2. The shrinkage-free high-ductility waterproof repair mortar according to claim 1, wherein the high-ductility functional system comprises, by weight, 0.2-0.4 part of modified sisal fiber, 1-5 parts of anhydrous calcium sulfate, 1-3 parts of ethylene-vinyl acetate copolymer, 1-5 parts of amorphous active silicon material, 0.04-0.1 part of defoamer, 0.01-0.05 part of lithium carbonate, 0.01-0.05 part of 400-viscosity cellulose ether, 0.1-0.2 part of thixotropic agent, 0.1-0.2 part of levorotatory tartaric acid and 0.1-0.2 part of sodium gluconate, and the controllable early strength system comprises, by weight, 10-30 parts of ordinary silicate cement, 10-30 parts of rapid hardening type thioaluminate cement, 22-35 parts of 20-40 mesh river sand and 20-30 parts of 40-70 mesh river sand.
3. The shrinkage-free high-ductility waterproof repair mortar of claim 1 or 2, wherein the modified sisal fibers are prepared from natural sisal fibers sequentially subjected to alkali treatment, plasma treatment and grafting treatment.
4. The shrinkage-free high-ductility waterproof repair mortar according to claim 3, wherein the natural sisal fibers are treated in an alkali solution with the mass concentration of 0.1-2%, the treated natural sisal fibers are dried at 40-70 ℃ to obtain alkali treated natural sisal fibers, the alkali treated natural sisal fibers are subjected to 80-110W power plasma treatment in an oxygen atmosphere to obtain surface active natural sisal fibers, and the surface active natural sisal fibers are premixed with maleic anhydride, dimethylformamide and dicumyl peroxide and extruded to obtain the modified sisal fibers.
5. The shrinkage-free high-ductility waterproof repair mortar of claim 4, wherein the mass ratio of the surface active natural sisal fibers, maleic anhydride, dimethylformamide and dicumyl peroxide is 100:5-10:0.01-0.05:0.5-0.8.
6. The shrinkage-free high-ductility waterproof repair mortar of claim 4 or 5, wherein the premixing sequence is to sequentially add surface active natural sisal fibers, maleic anhydride, dimethylformamide and dicumyl peroxide, and the extrusion temperature is 175-180 ℃.
7. The shrinkage-free high-ductility waterproof repair mortar of claim 1 or 3, wherein the silica content in the amorphous active silicon material is more than 90%, the particle size is 50nm or less, and the 7d activity index is 85% or more.
8. The non-shrink, high ductility, water resistant repair mortar of claim 1 or 3 or 7 wherein said defoamer is DF02 defoamer and said thixotropic agent is thixotropic lubricant 602.
9. A preparation method of the shrinkage-free high-ductility waterproof repair mortar according to claim 1,3, 7 or 8 is characterized by comprising the steps of stirring modified sisal fibers, anhydrous calcium sulfate, ethylene-vinyl acetate copolymer, amorphous active silicon material, defoamer, lithium carbonate, cellulose ether, thixotropic agent, levorotatory tartaric acid and sodium gluconate in a high-pressure hot air environment to obtain a high-ductility functional system, mixing and stirring ordinary portland cement, quick-hardening sulphoaluminate cement, 20-40 mesh river sand and 40-70 mesh river sand to obtain a controllable early-strength system, and conveying the high-ductility functional system and the controllable early-strength system into a vacuum stirrer to be uniformly stirred.
10. The method for preparing the shrinkage-free high-ductility waterproof repair mortar according to claim 9, wherein the temperature in the hot air environment is 60-70 ℃.

Description

Shrinkage-free high-ductility waterproof repair mortar and preparation method thereof Technical Field The invention relates to the technical field of waterproof mortar, in particular to shrinkage-free high-ductility waterproof repair mortar and a preparation method thereof. Background During the service period of the concrete structure, due to the effects of load and external factors, the surface of the concrete structure is easy to generate defects such as loosening and peeling, even micro cracks are generated in the material, if the defects cannot be repaired in time, external water and aggressive media continuously infiltrate from the defects on the surface of the material, and finally accelerated degradation of the durability of the concrete is caused. The failure accidents of concrete structures caused by cracking, denudation, looseness and the like frequently occur, and the structural failure or building function failure caused by various reasons in the world at present not only affects the normal life of people, but also causes great economic loss. More than 40% of the total investment in construction in the industrially developed countries is used for repairing and reinforcing the building, and less than 60% is used for the construction of new building. 40% of bridges in the United states are severely damaged, while about 30% of cement concrete pavement in China is damaged, and obviously, the damaged facilities are completely replaced or rebuilt, which is economically infeasible, and the solution is only repair. The concrete structure repair has important practical significance for preventing the environmental erosion of concrete, maintaining the service performance of the concrete, and ensuring and improving the durability and the service life of the concrete structure. The repairing mortar is special cement-based polymer mortar for concrete structure surface defect and reinforcement construction, has higher compressive strength, cohesiveness, crack resistance and waterproofness, and can be used for repairing the surface of an industrial and civil cracked concrete building or repairing an industrial and civil building which is damaged and cannot meet design requirements. The cement-based repair mortar is mortar formed by mixing cement, fine aggregate (particle size is smaller than 4.75 mm), water, lime and additives which are added according to the requirement. The repair of reinforced concrete building surface repair, repair of concrete honeycomb, hole and other defects, repair of damaged concrete ground, and repair of concrete and masonry structure surface, repair engineering of underground pipeline, power plant cooling tower, chimney, chemical plant structure and various factory buildings with corrosive gas, civil building, ultra-fast repair of bridge and road, emergency repair of military engineering road and other fields. The method has application in the fields of rapid road surface rush repair, rapid bridge expansion joint repair, rapid tunnel repair, anti-collision wall repair, anchoring, rapid guardrail installation and the like in severe cold areas in winter. Cracking of the existing repair mortar is the most remarkable technical problem. When the thickness of the single repair exceeds 50mm, the hydration heat accumulation in the material is difficult to diffuse, and the temperature stress crack is easy to be initiated. Material shrinkage control is also challenging, the 28-day shrinkage of common repair mortar is usually in the range of 0.08-0.12%, and shrinkage cracks are extremely easy to generate when the bonding strength between the repair mortar and an old concrete interface is insufficient. Secondly, the repair mortar needs to strictly control the setting and hardening time, so that the repair mortar has enough working time, is fast to cure after construction and has high early strength. And the working state is flexible, and the slurry is thick and cannot slip and deform. In partial application scenes such as rapid repair of bridge expansion joints and rapid repair of tunnels, water carrying operation and even water moving operation are required, the common cement-based repair mortar is affected by water in the scenes in construction, the water-material ratio is changed, and even part (all) of components are washed away by water, so that the quality of repair engineering cannot be guaranteed. Disclosure of Invention The application aims to provide a shrinkage-free high-ductility waterproof repair mortar and a preparation method thereof, wherein the waterproof repair mortar has a controllable early-strength system, can repair a damaged structure rapidly, can be effectively bonded in unfavorable environments such as humidity, vertical surfaces and the like, can keep the system crack and not break when external force damage is received, and can effectively stop leakage. In order to achieve the above object, the present application provides the following technical solutions: The non-s