Waterproof construction method for underground structure exterior wall

Abstract

The present invention provides a waterproof construction method for the exterior wall of an underground structure, comprising the following steps: performing reinforcement and formwork construction on the exterior wall on the underground structure base plate to construct an exterior wall frame; pouring waterproof concrete within the exterior wall frame to form the underground exterior wall; cleaning and repairing the exterior wall after curing the underground exterior wall; applying waterproof mortar to the exterior wall to form a waterproof layer; and backfilling the fertilizer trough to complete the construction of the exterior wall of the underground structure. The present invention employs two waterproof defenses: a rigid waterproof layer and a self-waterproof concrete structure made of water-based mud. The two layers are highly compatible, fundamentally resolving quality defects such as "water leakage," "cold seams," and "honeycomb holes," reducing concrete cracking, and improving concrete strength and impermeability and waterproofing performance, achieving the quality effect of "one-time construction, lifetime repair-free" while simultaneously reducing project development and construction costs.

Description

Technical Field

[0001] The present invention relates to the field of building waterproofing, and in particular to a waterproofing construction method for the outer wall of an underground structure. Background Art

[0002] Currently, with the expansion of construction projects across my country, the demand for underground space is increasing. However, due to the unique environment of basements, strict requirements are imposed on their waterproofing, anti-seepage, and crack resistance. Water seepage through basement exterior walls is a common problem in buildings, significantly impacting their functionality. Furthermore, basement leaks can lead to high repair costs and difficulties.

[0003] Rigid waterproofing has existed since the founding of the People's Republic of China. However, due to process bottlenecks in the early years, it failed to completely solve problems such as waterproofing leakage and was gradually replaced by flexible waterproofing methods. In recent years, with the widespread application of new technologies and materials, rigid waterproofing technology has greatly improved. In addition, flexible waterproofing still cannot completely solve the problem of water leakage in underground waterproofing projects. Rigid waterproofing is gradually being accepted by the market due to its low cost, short construction time and good results.

[0004] The current "rigid-flexible" waterproofing process involves applying a flexible waterproof layer to the exterior of the structure to compensate for the structural concrete's waterproofing deficiencies. However, during construction, quality issues such as "honeycomb holes" and "cold joints" in the rigid concrete are often overlooked, while the flexible waterproof layer is prone to water leakage, leading to later-stage leakage in buildings. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a waterproof construction method for the outer wall of an underground structure, which adopts two waterproof defenses made of water-based mud materials, namely a rigid waterproof layer and a self-waterproof concrete structure. The two have good compatibility, and solve the quality defects such as "water seepage", "cold seams", and "honeycomb dog holes" from the root, reduce concrete cracking, improve concrete strength and anti-seepage and waterproof performance, and achieve the quality effect of "one-time construction, lifelong maintenance-free", while reducing project development and construction costs.

[0006] The invention provides a waterproof construction method for an outer wall of an underground structure, comprising the following steps: carrying out steel bar construction and formwork construction of the outer wall on a bottom plate of the underground structure, and building an outer wall frame; pouring waterproof concrete in the outer wall frame to form an underground outer wall, wherein the thickness of the overall structure is not less than 170 mm; the waterproof concrete comprises 10 wt% of cement, 76.5 wt% of sand and gravel, 0.3 wt% of water reducer, 3.3 wt% of fly ash, 2.5 wt% of slag powder, 7.4 wt% of water, and 0.15-0.25 wt% of a waterproof densifier based on the total weight of cement, sand and gravel; after curing the underground outer wall, cleaning and repairing the outer wall; applying waterproof mortar on the outer wall to form a waterproof layer; the thickness of the waterproof mortar is 10-20 mm; the waterproof mortar comprises 28 wt% of cement, 56 wt% of sand, 16 wt% of water, and 0.15-0.25 wt% of a mortar waterproofing agent based on the weight of cement; and backfilling a fertilizer tank to complete the construction of the outer wall of the underground structure.

[0007] Furthermore, before pouring the waterproof concrete, cement, sand, fly ash, slag powder and water are mixed evenly, and the water reducer is added and mixed; after adding the waterproof densifier at the construction site, the mixture is stirred for ≥5 minutes before pouring.

[0008] Furthermore, the exterior walls are cleaned and repaired, including:

[0009] Clean and repair the cracks, rough surfaces, holes or gaps at the rough joints to ensure that the exterior wall surface is smooth and clean; finally, perform a roughening treatment.

[0010] Furthermore, before the construction of the waterproof mortar, the cement, sand and water are mixed evenly. After adding the mortar waterproofing agent at the construction site, the mixture is stirred for ≥3 minutes before pouring.

[0011] Furthermore, the waterproof mortar is applied in layers, and the application of the upper layer of waterproof mortar is completed before the initial setting of the bottom layer of waterproof mortar; before applying the bottom layer of waterproof mortar, the exterior wall surface is moistened.

[0012] Furthermore, the water reducer is selected from one or more combinations of lignin sulfonate water reducers, naphthalene water reducers, melamine water reducers, aminosulfonate water reducers, fatty acid high water reducers, and polycarboxylate water reducers.

[0013] Furthermore, the mortar waterproofing agent includes: 6-20wt% sodium dodecylbenzenesulfonate, 1.2-18wt% oleoyl polypeptide complex, 5-15wt% silicate, 20-40wt% calcium hydroxide and 7-67.8wt% water; and the weight ratio of sodium dodecylbenzenesulfonate to oleoyl polypeptide complex is 1:(0.2-0.9).

[0014] Furthermore, the waterproof densifier includes: 3-8wt% sodium dodecylbenzenesulfonate, 3-10wt% carboxylic acid surfactant, 5-15wt% silicate, 20-40wt% calcium hydroxide and 30-60wt% water; and the weight ratio of sodium dodecylbenzenesulfonate to oleoyl polypeptide complex is 1:(1-3).

[0015] Furthermore, the oleoyl polypeptide complex is a combination of one or more of N-oleoyl polypeptide, sodium N-oleoyl polypeptide, and N-alkanoyl polypeptide; the silicate is a combination of one or more of sodium silicate, lithium silicate, aluminum silicate, and calcium silicate.

[0016] The present invention achieves waterproofing of the exterior walls of underground structures by adding additives with waterproofing effects to mortar and concrete. The specific principles are as follows:

[0017] By adding a mortar waterproofing agent to the mortar, the silicates within react with the hydration products of the cement to form a gel containing silicate groups. As an aggregate component, the gel fills and blocks the pores in the concrete during its growth, thereby cutting off the connectivity of capillaries, reducing the porosity within the concrete and improving its density and impermeability. Under alkaline conditions, the oleoyl polypeptide complex and sodium dodecylbenzene sulfonate neutralize the alkali generated by cement hydration, maintaining a long-term internal environment in the mortar and preventing alkali reversion. The oleoyl polypeptide complex and sodium dodecylbenzene sulfonate act as surfactants, improving the fluidity of the mortar and reducing cracking and shrinkage. The oleoyl polypeptide complex, as an auxiliary surfactant, also has foaming, dispersing, suspending, and adsorbing properties, which improve the uniformity of the waterproofing agent and prevent the precipitation of aggregate components from the internal reaction, thereby stabilizing its performance. A mortar waterproofing layer is applied to the exterior of the concrete to block contact between the internal reaction and the outside air, preventing the ingress of carbon dioxide from the air, extending the life of the concrete, and improving its water-leakage resistance.

[0018] Adding waterproof densifier to concrete makes it waterproof concrete. This is because during the concrete construction, the hydration reaction process inside the concrete will produce pores such as "honeycomb dog holes" and "cold joints". The silicate in the waterproof densifier reacts with the hydration products of cement to form a gel containing silicate groups. As an aggregate component, the gel will fill and block the pores in the concrete during its growth, thereby cutting off the connectivity of the capillary channels, reducing the porosity inside the concrete, and improving the density and impermeability. Moreover, as long as the silicate is not exhausted, the gel will continue to be generated and continuously block the pores. The silicate can not only greatly increase the impermeability, but also with the passage of time, in the presence of water, the impermeability effect will become better and better, and the penetration depth will increase. At the same time, the presence of the gel reduces the production of concrete during the drying process. The volume shrinkage and cracking caused by the oleoyl polypeptide complex are complexed with sodium dodecylbenzene sulfonate under alkaline conditions to form a complex, which neutralizes the alkali inside, maintains the internal environment of the concrete for a long time, and prevents the occurrence of alkali backflow; at the same time, a large number of tiny bubbles are generated, which cut off the capillary pathways generated during the hardening process of the concrete, reduce the capillary effect, and improve the impermeability; the oleoyl polypeptide complex helps the surfactant molecules to extend, significantly reduces the interaction between surfactant molecules, and improves the effect of the surfactant; sodium dodecylbenzene sulfonate can destroy the electrostatic attraction generated in the concrete system, improve the dispersion of aggregate components, make them more evenly distributed in the interior of the concrete, and increase the density of the concrete; at the same time, sodium dodecylbenzene sulfonate has a strong permeability in water and can react with Ca in cement paste 2+ Complexation forms a complex. When the complex is SiO3 2- The sodium dodecylbenzenesulfonate is replaced by other substances, producing crystals or precipitates to block the pores, thereby increasing the impermeability; and the sodium dodecylbenzenesulfonate will not be consumed, thus having long-lasting waterproof properties.

[0019] The present invention employs a composite waterproof structure formed by applying waterproof mortar and waterproof concrete to the exterior walls of basements, fundamentally resolving building leakage issues and improving waterproofing quality. Concrete containing a waterproofing densifier can enhance the gel density and impermeability of concrete, reduce early concrete shrinkage, and, under certain conditions, control the formation of concrete cracks. The waterproof mortar containing a mortar waterproofing agent can provide the impermeability of cement mortar, forming an effective waterproof layer and achieving dual protection. This eliminates water leakage between the two waterproof layers, simplifies construction procedures, reduces construction time, and increases the lifespan of waterproofing.

[0020] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0022] Figure 1 This is a diagram of the waterproofing construction process of the basement exterior wall of this embodiment;

[0023] Figure 2 It is a schematic diagram of the waterproof structure of the basement exterior wall of this embodiment.

[0024] in, Figure 1-2 The corresponding relationship between the reference numerals and component names in FIG. 1 is as follows:

[0025] 1. Backfill soil; 2. Mortar waterproof layer; 3. Waterproof concrete; 4. Foundation pit excavation boundary; 5. Base plate. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0028] according to Figure 1 and Figure 2 As shown, the present invention provides a waterproof construction method for the outer wall of an underground structure, comprising the following steps:

[0029] S1: Carry out reinforcement and formwork construction of the exterior wall on the underground structure bottom plate 5 and build the exterior wall frame;

[0030] Complete reinforcement construction according to design requirements. Reinforcement is used to enhance the internal structure of the concrete. Therefore, before waterproofing the concrete, various rebars or binding wires must be installed, ensuring they do not contact the formwork. To ensure waterproofing, a waterstop must be buried, which can be constructed from steel plates. When bolts securing the formwork must pass through the waterproof concrete structure, tool bolts or bolts with plugs can be used, and square waterstop rings should be welded to the bolts. After removing the formwork, reinforced waterproofing measures should be implemented to tightly seal the remaining grooves.

[0031] S2: Waterproof concrete is poured in the outer wall frame to form an underground outer wall, and the thickness of the overall structure is not less than 170 mm; the waterproof concrete includes 10 wt% cement, 76.5 wt% sand and gravel, 0.3 wt% water reducer, 3.3 wt% fly ash, 2.5 wt% slag powder, 7.4 wt% water and 0.15-0.25 wt% of the total weight of cement and gravel; the preferred addition amount of the waterproof density agent is 0.16 wt%, 0.17 wt%, 0.19 wt%, 0.2 wt%, 0.21 wt%, 0.23 wt% and 0.24 wt% of the total weight of cement and gravel.

[0032] When waterproof concrete is mixed manually on site, the mixing time must not be less than 5 minutes. When vigorously stirred, the mixing time must not be less than 30 seconds. If segregation occurs in the waterproof concrete mixture after transportation, it must be mixed a second time. When the slump loss fails to meet the construction requirements, cement slurry with an original water-cement ratio of 0.46 or a second water-reducing agent should be added for stirring. Water should not be added directly.

[0033] When ready-mixed concrete is used for waterproof concrete, the slump entering the pump should be controlled at 160-180mm, the slump loss per hour should not be greater than 20mm, and the total slump loss should not be greater than 40mm.

[0034] The waterproof concrete in the same construction section shall be poured continuously, and the upper layer of waterproof concrete shall be poured before the initial setting of the bottom layer of waterproof concrete.

[0035] Waterproof concrete must be vibrated to compaction. The vibration time should be 10 to 30 seconds, ensuring that the waterproof concrete is slurry-free and free of bubbles. Avoid missed, under-vibrated, or over-vibrated concrete. When pouring and vibrating the upper layer of concrete in layers, insert the vibrating rod approximately 50 mm into the lower layer. Eliminate joints between layers to ensure the integrity of the concrete structure. Vibration should be completed before the next layer of concrete begins to set. The duration of vibration at each vibration point should be sufficient to avoid segregation caused by excessive vibration.

[0036] Waterproof concrete should be poured continuously, with minimal or no construction joints. When construction joints are necessary, the following guidelines should be followed: Horizontal construction joints in the wall should not be located at the points of maximum shear and bending moments, or at the junction of the base plate and exterior wall. They should be located in the wall at least 500mm above the base plate surface. Horizontal construction joints in the arch (slab)-wall connection should be located 150-300mm below the arch (slab)-wall joint line. When the wall has pre-existing holes, the construction joint should be at least 300mm from the edge of the hole. Vertical construction joints should be avoided in areas with high levels of groundwater and fissure water, and should be combined with expansion joints.

[0037] S3: After curing the underground exterior wall, cleaning and repairing the exterior wall;

[0038] The waterproof concrete should be cured for ≥14 days after final setting. During winter construction, the temperature of the waterproof concrete entering the mold must not be lower than 10°C. It is advisable to adopt comprehensive heat storage method, greenhouse method and other curing methods, and the concrete surface should be kept moist to prevent early dehydration of the concrete.

[0039] Specifically, it is necessary to clean and repair the cracks, rough surfaces, holes or gaps on the exterior wall and the rough joints to ensure that the exterior wall surface is flat and clean; finally, do a roughening treatment.

[0040] S4: Apply waterproof mortar to the exterior wall to form a waterproof layer; the thickness of the mortar waterproof cushion layer is 10-20 mm; the waterproof mortar comprises 28 wt% cement, 56 wt% sand, 16 wt% water and 0.15-0.25 wt% of the weight of the cement in a mortar waterproofing agent; the preferred addition amount of the mortar waterproofing agent is 0.16 wt%, 0.17 wt%, 0.19 wt%, 0.2 wt%, 0.21 wt%, 0.23 wt% and 0.24 wt% of the weight of the cement.

[0041] The specific process is: base inspection and cleaning, detailed processing, wall watering and moistening, pouring of waterproof mortar protective layer, maintenance, waterproof layer inspection, and after acceptance, the next step of construction will be carried out.

[0042] Specifically, before applying waterproof mortar, it must undergo a joint inspection by all parties. The exterior wall surface should be flat, rough, solid, clean, and free of peeling, sanding, or looseness. It should be fully moistened, free of water accumulation, through-holes, and no residual separation or expansion joints. If the wall surface has cracks, pitting, holes, or gaps, and the joints are not smooth, detailed pre-treatment is required.

[0043] Premixed waterproof mortar is prepared by mixing ordinary Portland cement, medium sand, and water. During mixing at the construction site, dilute the mortar waterproofing agent diluent at a weight ratio of 1:200 (mortar waterproofing agent: water). Add a certain amount of mortar waterproofing agent diluent to the cement based on the desired waterproofing performance. Stir the mortar for at least 3 minutes, and use the waterproof mortar within 2 hours. If mortar segregation occurs during construction, remix the mortar. Add cement slurry and mortar waterproofing agent diluent as necessary. Do not add water at will to ensure the waterproofing effect of the mortar waterproofing agent. During waterproof mortar construction, ensure proper thickness control, ranging from 10-20 mm. Increase the thickness appropriately based on design requirements and the desired waterproofing grade.

[0044] Waterproof mortar should be applied in layers, with the upper layer completed before the lower layer begins to set. Before applying the lower layer, moisten the exterior wall surface and apply the waterproof mortar by brushing or smearing it evenly, avoiding any buildup. Each layer of mortar should be applied continuously and tightly together. During construction, the waterproof mortar should be compacted to ensure the required waterproofing properties. When applying the upper layer of mortar, ensure that it is pressed into the lower layer to ensure a tight bond between the mortar layers.

[0045] During the construction of waterproof mortar, construction joints should not be left. If joints must be left due to unforeseen circumstances, they should be stepped and sloped. The joints between each layer should be staggered by 150mm and should not be less than 250mm from the corners. Construction joints should be at least 300mm away from the corners and pipelines passing through the wall. Horizontal joints should be left on the wall, and the joint location should be approximately 1 / 2 of the height of each basement floor. Joints should be made in a layered order, with each layer tightly overlapped. At the corners, the corners should be constructed first, followed by the application of waterproof mortar. The corners should be made into small arcs of 50mm. The diameter of the inner corner should be greater than 50mm, and the diameter of the outer corner should be greater than 10mm. The waterproof overlap length of the inner corner is 250mm, and the waterproof end height is 500mm above the façade.

[0046] Finally, flexible sealing materials are used to seal the nodes such as the post-pouring joints, construction joints, and the roots of the wall-penetrating pipes, and the waterproof layer is inspected to ensure that there are no construction quality problems such as hollows, honeycombs, and sand holes.

[0047] S5: Backfill the fertilizer tank and complete the construction of the underground structure exterior wall; complete the backfill of the basement fertilizer tank according to the design requirements, such as Figure 2 As shown, in the foundation pit, backfill soil 1 is backfilled between the waterproof mortar layer 2 outside the basement outer wall and the foundation pit excavation boundary 4 to complete the underground construction.

[0048] In the above-mentioned embodiment, when large-volume waterproof concrete is constructed, if the design permits, the 60d strength of the concrete is used as the design strength; low-heat or medium-heat cement is used, and admixtures such as fly ash and slag powder are added and used in combination with admixtures such as water reducers, retarders, air entraining agents, and pumping agents; during construction in hot seasons, cooling measures such as lowering the temperature of raw materials and reducing the absorption of external heat by concrete during transportation are adopted; pipes can be pre-buried inside the concrete for cold water heat dissipation; thermal insulation and moisturizing maintenance are adopted; the difference between the center temperature and the surface temperature of the concrete should not be greater than 25°C, and the difference between the surface temperature of the concrete and the atmospheric temperature should not be greater than 25°C, and the curing time should not be less than 14d.

[0049] In the above embodiment, the mortar waterproofing agent includes: 6-20wt% sodium dodecylbenzenesulfonate, 1.2-18wt% oleoyl polypeptide complex, 5-15wt% silicate, 20-40wt% calcium hydroxide and 7-67.8wt% water; and the weight ratio of sodium dodecylbenzenesulfonate to oleoyl polypeptide complex is 1:(0.2-0.9).

[0050] The preparation method of a mortar waterproofing agent includes the following steps: adding sodium dodecylbenzenesulfonate to water and stirring to dissolve it to form a solution; adding an oleoyl polypeptide complex to the solution and stirring to form a primary solvent; adding three-fifths of calcium hydroxide to the primary solvent and stirring to form an intermediate solvent; adding the remaining calcium hydroxide and stirring to form a silicate, and stirring to form a waterproofing agent. The mortar waterproofing agent is added at 0.15-0.25wt% of the total cement content in the mortar.

[0051] Mortar waterproofing agent is a composite of silicate, sodium dodecylbenzene sulfonate and oleoyl polypeptide that interacts with each other in the environment of calcium hydroxide to introduce -COO - , -COONa, -SO3Na and other structures are highly effective in chelating Ca in cement 2+ 、Al 3+ Plasma, thereby forming a stable and dense waterproof layer, solving the problem of poor compatibility and easy stratification and fracture between organic polymers and inorganic cement; at the same time, giving the waterproofing agent hydrophobic properties, improving the workability, crack resistance and waterproof performance of the mortar as a whole, and as an additional waterproof layer, cooperating with the concrete self-waterproof structure to completely solve the problem of water leakage.

[0052] In the above embodiment, the waterproofing and densifying agent includes: 3-8wt% sodium dodecylbenzenesulfonate, 3-10wt% carboxylic acid surfactant, 5-15wt% silicate, 20-40wt% calcium hydroxide and 30-60wt% water; and the weight ratio of sodium dodecylbenzenesulfonate to oleoyl polypeptide complex is 1:(1-3).

[0053] The preparation method of a waterproofing and compacting agent comprises the following steps: adding sodium dodecylbenzenesulfonate to water and stirring to dissolve to form a solution; adding an oleoyl polypeptide complex to the solution and stirring to form a primary solvent; adding three-fifths of calcium hydroxide to the primary solvent and stirring to form an intermediate solvent; adding the remaining calcium hydroxide and stirring to form a silicate, and stirring to form a waterproofing and compacting agent. The waterproofing and compacting agent is added at 0.15-0.25wt% of the total mortar cement content in the concrete.

[0054] The waterproof compacting agent uses silicate, sodium dodecylbenzene sulfonate, and oleoyl polypeptide complex to interact with each other in the environment of calcium hydroxide to introduce -COO -, -COONa, -SO3Na and other structures are highly effective in chelating Ca in cement 2+ 、Al 3+ Plasma, thereby forming a stable and dense waterproof layer, solving the problem of poor compatibility and easy stratification and fracture between organic polymers and inorganic cement; at the same time, giving the waterproof densifier hydrophobic properties, the overall modified cement-based waterproof concrete has the characteristics of good impermeability, low water absorption, waterproof and anti-fouling, and further improving the strength and mechanical properties of concrete.

[0055] In the above embodiment, the water reducer is selected from one or more combinations of lignin sulfonate water reducers, naphthalene water reducers, melamine water reducers, aminosulfonate water reducers, fatty acid high water reducers, and polycarboxylate water reducers.

[0056] In the above embodiment, the oleoyl polypeptide complex is a combination of one or more of N-oleoyl polypeptide, sodium N-oleoyl polypeptide, and N-alkanoyl polypeptide; the silicate is a combination of one or more of sodium silicate, lithium silicate, aluminum silicate, and calcium silicate.

[0057] In the above implementation method, the material requirements during the construction process are as follows:

[0058] The testing requirements for mortar waterproofing agents and waterproof densifiers shall comply with the requirements of JC474 "Mortar and Concrete Waterproofing Agents"; ordinary Portland cement or Portland cement should be used as cement with a strength grade of not less than 32.5Mpa. It is strictly prohibited to use expired or damp cement, and cements of different brands or strength grades shall not be mixed; the sand used for mortar waterproofing layer should be medium sand with a mud content of not more than 1% and a sulfide and sulfate content of not more than 1%; the sand and gravel used for waterproof concrete should be composed of medium sand and gravel, of which medium sand should be used as cement. The mud content of sand shall not exceed 3.0%, and the mud block content shall not exceed 1.0%. Sea sand should not be used. The maximum particle size of gravel should not be greater than 40 mm. When pumping, its maximum particle size should be 1 / 4 of the conveying pipe diameter. The mud content shall not exceed 1.0%, the mud block content shall not exceed 0.5%, and the water absorption rate shall not be greater than 1.5%. Other requirements for sand and gravel shall comply with the provisions of "Standard for Quality and Test Methods of Sand and Stone for Ordinary Concrete" JGJ52-2006; water shall comply with the provisions of "Standard for Water Use in Concrete" JGJ63-2006.

[0059]

Test of exterior wall waterproof performance

[0060] The number of waterproof exterior wall test blocks produced should meet the requirements of the specification. The concrete strength grade, anti-seepage grade, mix ratio and construction process of the same exterior wall are basically the same. The internal structure is as follows: Figure 2As shown, the exterior wall from inside to outside is: waterproof concrete 3, waterproof mortar 2 and backfill soil 1. Each unit project shall not be less than 2 groups of test blocks, each group of six test blocks; continuous pouring of waterproof concrete every 500m 3 Leave a group of anti-seepage test pieces, less than 500m 3 The sampling shall not be less than one group, and each project shall not be less than 2 groups. The compressive strength test piece shall be retained at the same time as the impermeability test piece. The sampling method is the same as that of ordinary concrete, and the test piece shall be made at the pouring site. The specific performance data is shown in Table 1:

[0061] Table 1 Anti-cracking and waterproof performance data of waterproof concrete and ordinary concrete

[0062]

[0063] It can be clearly seen from the above table that

[0064] Waterproof concrete consists of a mortar layer with a mortar waterproofing agent and a waterproof concrete layer with a waterproof densifier. Compared to ordinary concrete without a waterproofing agent, waterproof concrete has low initial compressive strength and a relatively large shrinkage ratio, but gradually increases in compressive strength and has a significantly smaller shrinkage ratio in the later stages. At the end of the 60-day shrinkage period, the total shrinkage is less than that of ordinary concrete. This indicates that the shrinkage ratio of waterproof concrete decreases with increasing compressive strength, which helps control the release of concrete deformation. The total shrinkage is reduced, and the crack resistance is significant. Furthermore, the water permeability pressure ratio is high, and water absorption is low, making it an excellent crack and seepage preventer.

[0065] From the above conclusions, it can be seen that the present invention starts from changing the quality of the concrete structure of the building. During construction, the waterproof densifier is first added to the concrete, which reacts chemically with the cement hydration precipitate to generate gel and crystals, fill the tiny gaps in the cement stone, inhibit the penetration of pressurized water, and improve the fluidity, density and impermeability of the mortar and concrete, thereby achieving the first rigid self-waterproofing purpose of the building structure. In order to ensure that the building is leak-proof after it is put into use, a waterproof mortar containing a mortar waterproofing agent is applied to the water-facing surface of the structural concrete to achieve the second rigid waterproofing construction. The rigid additional waterproof layer is closely combined with the self-waterproofing of the concrete structure, which completely solves the problem of water leakage. The two waterproof defenses reinforce each other to achieve zero defects in waterproof quality.

[0066] The preferred embodiments of the present invention are described above. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0067] In the description of the present invention, the terms "connect," "install," and "fix" should be understood broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0068] In the description of the present invention, the terms "in the above-mentioned embodiments" or "in some embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in any one or more embodiments or examples.

[0069] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations of this application are possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the invention shall be included in the scope of protection of the present invention.

Claims

1. A waterproof construction method for the outer wall of an underground structure, characterized in that: The following steps are involved: Carry out reinforcement and formwork construction of the exterior wall on the underground structure slab and build the exterior wall frame; Waterproof concrete is poured into the outer wall frame to form an underground outer wall, and the thickness of the entire structure is not less than 170 mm; the waterproof concrete comprises 10 wt% cement, 76.5 wt% sand and gravel, 0.3 wt% water reducer, 3.3 wt% fly ash, 2.5 wt% slag powder, 7.4 wt% water, and 0.15-0.25 wt% of a waterproof densifier based on the total weight of the cement, sand and gravel; After curing the underground exterior wall, cleaning and repairing the exterior wall; Applying waterproof mortar on the exterior wall to form a waterproof layer; the thickness of the waterproof mortar is 10-20 mm; the waterproof mortar comprises 28 wt% cement, 56 wt% sand, 16 wt% water and 0.15-0.25 wt% of the weight of the cement in a mortar waterproofing agent; The mortar waterproofing agent comprises: 6-20 wt% sodium dodecylbenzene sulfonate, 1.2-18 wt% oleoyl polypeptide complex, 5-15 wt% silicate, 20-40 wt% calcium hydroxide and 7-67.8 wt% water; and The weight ratio of sodium dodecylbenzenesulfonate to oleoyl polypeptide complex = 1:(0.2-0.9); The fertilizer trough is backfilled and the construction of the outer wall of the underground structure is completed.

2. The construction method according to claim 1, characterized in that: Before pouring the waterproof concrete, cement, sand, fly ash, slag powder and water are mixed evenly, and a water reducer is added and mixed; after adding the waterproof densifier at the construction site, the mixture is stirred for ≥5 minutes and then the pouring operation is carried out.

3. The construction method according to claim 1, characterized in that: The cleaning and repairing of the exterior wall includes: Clean and repair the cracks, rough surfaces, holes or gaps and the rough joints to ensure that the exterior wall surface is smooth and clean; finally, perform a roughening treatment.

4. The construction method according to claim 1, characterized in that: Before the construction of the waterproof mortar, cement, sand and water are mixed evenly. After adding the mortar waterproofing agent at the construction site, stir for ≥3 minutes and then carry out pouring operation.

5. The construction method according to claim 1, characterized in that: The waterproof mortar is applied in layers, and the application of the upper layer of waterproof mortar is completed before the initial setting of the waterproof mortar of the bottom layer; before applying the waterproof mortar of the bottom layer, the exterior wall surface is moistened.

6. The construction method according to claim 1, characterized in that: The water reducer is selected from one or more combinations of lignin sulfonate water reducers, naphthalene water reducers, melamine water reducers, aminosulfonate water reducers, fatty acid high water reducers, and polycarboxylate water reducers.

7. The construction method according to claim 1, characterized in that: The waterproof and compacting agent comprises: 3-8 wt% sodium dodecylbenzene sulfonate, 3-10 wt% oleoyl polypeptide complex, 5-15 wt% silicate, 20-40 wt% calcium hydroxide and 30-60 wt% water; and The weight ratio of sodium dodecylbenzenesulfonate to the oleoyl polypeptide complex is 1:(1-3).

8. The construction method according to claim 7, characterized in that: The oleoyl polypeptide complex is an N-oleoyl polypeptide; The silicate is a combination of one or more of sodium silicate, lithium silicate, aluminum silicate and calcium silicate.

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