Humidity slow-release self-adjusting planting roof waterproof structure and construction method

Abstract

The application discloses a humidity slow-release self-adjusting planting roof waterproof structure and a construction method, and relates to the technical field of waterproof structures. The structure comprises, from bottom to top, a roof structure layer, a common waterproof layer, an insulation layer, a slope / flooring layer, a root penetration resistant waterproof layer, a waterproof protection layer, a water drainage / accumulation layer, a filter layer, a water absorption and moisture retention material layer, a planting soil layer and a vegetation layer. The water absorption and moisture retention material layer is composed of a gradient double-layer structure of water absorption and moisture retention material particles, the upper layer is a rapid water absorption layer, and the lower layer is a slow water release layer. The rapid water absorption layer is composed of high-porosity water interception channels of large-diameter water absorption and moisture retention material particles. The slow water release layer is composed of capillary barriers of small-diameter water absorption and moisture retention material particles. The application innovatively adds a water absorption and moisture retention material layer between the filter layer and the planting soil layer, and realizes gradient slow-release self-adjustment of soil humidity through gradient double-layer structure design, which can effectively improve the waterproof performance of the planting roof and the plant growth environment, and promote urban greening and environmental protection.

Description

Technical Field

[0001] This invention relates to the technical field of building waterproofing, and in particular to a moisture-releasing, self-regulating waterproofing structure for green roofs and its construction method. Background Technology

[0002] With the acceleration of urbanization, urban space is becoming increasingly scarce. Green roofs, as an effective form of urban greening, have received widespread attention due to their multiple advantages, including increasing urban green coverage, mitigating the "heat island effect," reducing air pollution, saving energy, intercepting rainwater, extending the lifespan of waterproofing layers, improving the ecological environment, and beautifying the urban landscape.

[0003] Green roofs typically have a complex structure, generally including a roof structure layer, a leveling layer, an insulation layer, a standard waterproofing layer, a root-penetration resistant waterproofing layer, a drainage (storage) layer, a filter layer, a planting soil layer, and a vegetation layer. Among these, the waterproofing layer is a key component of a green roof, its main function being to prevent water penetration and protect the building structure from water damage.

[0004] However, traditional waterproofing structures for green roofs have several problems. For example, plant roots have a strong penetrating ability during their growth, easily piercing ordinary waterproof membranes and causing the waterproofing layer to fail. Green roofs are constantly damp, and prolonged immersion in water can cause the waterproof membrane to curl and rot, thus reducing its waterproofing effectiveness. Existing waterproofing structures are complex to construct and costly, and may experience aging and damage over long-term use, affecting their waterproofing performance and lifespan. Traditional drainage systems need to handle large amounts of rainwater, which can easily lead to poor drainage and increase the load on the drainage system.

[0005] To address these issues, researchers and engineers are constantly exploring new waterproofing construction technologies and materials. For example, two waterproofing materials with different waterproofing principles are used to apply a two-layer waterproofing treatment to building roofs: one layer is a loose, impermeable sand, and the other is a root-penetration-resistant waterproofing material. The combined use of these two materials can effectively improve the overall waterproofing capability of the building roof structure. In addition, chemically modified bitumen waterproofing membranes resistant to root penetration have been developed. By adding chemical root inhibitors that suppress plant root growth to the modified bitumen coating, the growth of the root cuticle is promoted, limiting the root system's ability to absorb and transport nutrients, thereby inhibiting further root damage to the waterproofing layer. Nevertheless, existing green roof waterproofing structures still have some shortcomings.

[0006] Existing patents related to waterproofing construction of green roofs: CN220285188U: A waterproof structure for a green roof. Belonging to the field of roof construction technology, it includes, from top to bottom, a planting layer, a filter layer, a pebble and ceramsite layer, an elevated drainage layer, a root barrier layer, a waterproof layer, and a structural layer. The elevated drainage layer comprises multiple closely arranged drainage ribs, with permeable ribs between adjacent drainage ribs, forming a drainage cavity between the permeable and drainage ribs. The elevated drainage layer has the ability to collect water flow through the elevated drainage cavity and direct the water flow out, greatly enhancing its waterproof function. By dividing the original water storage and drainage layer into two structures—the pebble and ceramsite layer and the elevated drainage layer—the water storage capacity of the pebble and ceramsite layer and the drainage capacity of the elevated drainage layer are fully utilized, ensuring that the drainage and water storage functions of the green roof can maintain stable operation for a long time, improving the service life of the roof and preventing the risk of water leakage.

[0007] CN118383189A: An automatically irrigated green roof planting system device. This device includes a cultivation box and irrigation components; the cultivation box is equipped with irrigation components for irrigating grass seeds. This invention achieves seed positioning through limiting grooves on a limiting plate, preventing grass seeds from being washed into corners of the cultivation box by rainwater, thus avoiding pressure on the inner wall of the cultivation chamber during growth and improving seed growth.

[0008] CN222575957U: A rainwater harvesting and utilization type green green roof construction system, comprising, from bottom to top: a reinforced concrete roof panel, an aerated concrete layer, a cement mortar leveling layer, an insulation layer, a waterproof layer, a root-penetration resistant waterproof layer, a concrete protective layer, a ceramsite layer, a geotextile filter layer, planting soil, and a vegetation cover layer. The ceramsite layer contains infiltrative water pipes with both drainage and storage functions. This system combines traditional roof construction with landscape planting. Drainage and water storage facilities within the green roof, along with roof drains, collect and store rainwater. Combined with the rainwater harvesting and utilization system and water storage facilities, it enables reverse irrigation of the green roof vegetation. By leveraging the rainwater harvesting function of a sponge building, it achieves the goal of controlling and utilizing rainwater (excess water), alleviating urban flooding pressure while simultaneously saving water, energy, and reducing emissions.

[0009] CN222949334U: A rainwater siphon collection and drainage structure for a green roof, comprising a green roof slab, a leveling layer on the green roof slab, a waterproof membrane layer on the leveling layer, a root-penetration-resistant waterproof membrane layer on the waterproof membrane layer, a shaped sheet siphon layer and a siphon guide pipe arranged side by side on the root-penetration-resistant waterproof membrane layer, a geotextile filter layer on the shaped sheet siphon layer and the siphon guide pipe, and a planting layer on the geotextile filter layer. The beneficial effects of this utility model are: the geotextile is used for infiltrated sand filtration; the shaped sheet siphon layer is used for distributed regional rainwater collection and small-scale water conveyance and drainage; the siphon guide pipe is used for connected distributed regional trunk water conveyance and drainage; and the waterproof membrane is used for waterproofing and root penetration prevention, thereby achieving the overall waterproofing, water storage, drainage, and leak-proof functions of the planting layer.

[0010] CN203407268U: A greening structure for building rooftop greening, comprising a reinforced concrete roof layer, a waterproof protective layer on the roof layer, a root-resistant, drainage-preventing, and water-retaining layer on the waterproof protective layer, and a planting layer. The root-resistant, drainage-preventing, and water-retaining layer comprises an upper 5-8mm layer of highly absorbent resin material and a lower layer of root-resistant material formed by overlapping any one of non-woven fabric / glass cloth / plastic cloth. Green nutrient packs are placed in the planting layer. This patent simplifies the number of layers, reduces the building load, and the water-retaining layer uses highly absorbent resin to absorb water and form a miniature reservoir. The core limitation of this patent is that the highly absorbent resin only passively absorbs and slowly releases water, lacking a humidity-responsive active regulation function; the resin layer thickness is 5-8mm, limiting its water absorption capacity.

[0011] These patents address the drainage and waterproofing issues of green roofs from different perspectives, showcasing the diversity and innovation of green roof waterproofing construction technologies.

[0012] The core of patent (1) is a pebble ceramsite layer + an elevated drainage layer, which only has passive water storage capacity and no active water release function. The ceramsite layer is prone to clogging, and the construction is complicated and costly. The core of patent (2) is an automatic irrigation component, but it does not solve the core problems of waterproofing, root penetration, and uneven soil moisture. The core of patent (3) is a rainwater harvesting and utilization system, which can only passively collect rainwater and cannot actively regulate soil moisture, and does not solve the problems of root penetration and waterproof layer aging. The core of patent (4) is the siphon drainage structure, which can only optimize the drainage function, but has no moisturizing or humidity self-regulation function, and does not solve the core pain point of the prior art.

[0013] Patent (5) adopts a passive water storage method and lacks a mechanism to actively adjust the water release behavior according to the actual soil moisture.

[0014] In conclusion, the research and development of novel waterproofing technologies for green roofs with adjustable humidity are of great significance for solving the problem of leakage in green roofs and promoting urban greening. Through continuous innovation and improvement, it is expected to provide more reliable technical support for the widespread application of green roofs. Summary of the Invention

[0015] This invention provides a moisture-releasing, self-regulating waterproof structure and construction method for green roofs, which can effectively improve the waterproof performance of green roofs and the plant growth environment, thus promoting urban greening and environmental protection.

[0016] The technical problem to be solved is: 1. Plant roots penetrate the waterproof layer: Plant roots have a strong piercing ability during growth and can easily penetrate ordinary waterproof membranes, causing the waterproof layer to fail. 2. Long-term water immersion leads to aging of the waterproofing layer: Green roofs are in a damp state for a long time. The water immersion in the waterproofing layer for a long time will cause the membrane to curl and rot, thereby reducing the waterproofing effect. 3. Uneven soil moisture: It is difficult to maintain uniform moisture in the planting soil layer, which can easily lead to uneven plant growth and affect the greening effect; 4. Passive water storage cannot be actively regulated: Existing superabsorbent resins can only passively absorb and slowly release water, and cannot actively regulate the water release rate according to the actual changes in soil moisture, resulting in problems of excessive or insufficient water release. 5. Complex construction: Existing waterproofing structures are complex to construct and costly. Furthermore, they may experience aging and damage during long-term use, affecting the waterproofing effect and service life. 6. Heavy burden on drainage system: Traditional drainage systems need to handle a large amount of rainwater, which can easily lead to poor drainage and increase the load on the drainage system; 7. Temperature fluctuations affect plant roots: Green roofs are exposed to the outdoor environment, and the drastic fluctuations in high temperatures in summer and low temperatures in winter directly affect the growth of plant roots. Current technology lacks an effective temperature buffering mechanism.

[0017] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A humidity-controlled, self-regulating waterproof structure for a green roof includes, from bottom to top, a roof structure layer, a general waterproof layer, a thermal insulation layer, a slope-finding / leveling layer, a root-penetration-resistant waterproof layer, a waterproof protective layer, a drainage / water-storage layer, a filter layer, a water-absorbing and moisture-retaining material layer, a planting soil layer, and a vegetation layer. The water-absorbing and moisturizing material layer consists of a gradient double-layer structure composed of water-absorbing and moisturizing material particles. The upper layer is a fast water-absorbing layer, and the lower layer is a slow water-releasing layer. The fast water-absorbing layer is composed of large-diameter water-absorbing and moisturizing material particles forming a high-porosity water-blocking channel; the slow water-releasing layer is composed of small-diameter water-absorbing and moisturizing material particles forming a capillary barrier.

[0018] The present invention discloses a moisture-releasing self-regulating waterproof structure for a green roof. Furthermore, the particle size of the large-diameter water-absorbing and moisture-retaining material particles is 15~20mm, and the particle size of the small-diameter water-absorbing and moisture-retaining material particles is 5~10mm.

[0019] The present invention discloses a moisture-releasing self-regulating waterproof structure for a green roof. Furthermore, the porosity of the large-diameter water-absorbing and moisture-retaining material particles is ≥35%, and the porosity of the small-diameter water-absorbing and moisture-retaining material particles is 15%~35%.

[0020] This invention discloses a moisture-releasing, self-regulating waterproof structure for green roofs. Furthermore, the water-absorbing and moisture-retaining material particles are made of a composite superabsorbent resin-based material. The present invention discloses a moisture-releasing self-regulating waterproof structure for green roofs. Furthermore, the composite superabsorbent resin-based material includes superabsorbent resin, inorganic mineral filler, plant fiber reinforcing agent, anti-aging agent, and water-retaining agent.

[0021] The present invention discloses a moisture-releasing self-regulating waterproof structure for a green roof. Further, the mass percentage of each component of the composite superabsorbent resin-based material is as follows: superabsorbent resin: 40%-50%; inorganic mineral filler: 20%-30%; plant fiber reinforcing agent: 10%~15%; anti-aging agent: 2%~5%; water-retaining agent: 3%~10%.

[0022] The present invention discloses a moisture-releasing and self-regulating waterproof structure for a green roof. Further, the bottom surface of the water-absorbing and moisture-retaining material layer is connected to the filter layer through an adhesive layer, and a wire mesh is laid on the top surface. The wire mesh is connected to the filter layer through expansion nails, and the water-absorbing and moisture-retaining material is pressed and fixed onto the filter layer by the wire mesh.

[0023] The present invention discloses a moisture-releasing self-regulating waterproof structure for a green roof. Furthermore, the thickness of the rapid water absorption layer is 30-60mm, and the thickness of the slow water release layer is 20-40mm.

[0024] The present invention discloses a construction method, comprising the following steps: Step 1: Roof structural layer treatment, cleaning impurities and repairing cracks; Step 2: Construction of ordinary waterproof layer; Step 3: Insulation layer construction; Step 4: Construction of the slope / leveling layer; Step 5: Construction of root-penetration resistant waterproof layer; Step 6: Apply the waterproof protective layer; Step 7: Construction of drainage / storage layer; Step 8: Filter layer construction; Step 9: Construction of the water-absorbing and moisture-retaining material layer. Apply adhesive to the surface of the filter layer, lay water-absorbing and moisture-retaining material granules, scrape it flat, press the water-absorbing and moisture-retaining material granules to make the granules fully bond with the adhesive, fully lay wire mesh on the top surface of the water-absorbing and moisture-retaining material granules, and connect the wire mesh to the filter layer with expansion nails. Fix the water-absorbing and moisture-retaining material on the filter layer by pressing it with the wire mesh. Step 10: Construction of the planting soil layer; Step 11: Vegetation layer construction.

[0025] Compared with the prior art, the present invention has the following beneficial effects: (1) Humidity self-regulation function: The core of this invention lies in adding a composite superabsorbent resin-based water-absorbing and moisturizing material layer between the filter layer and the planting soil layer. This material layer can absorb 500 to 1000 times its own weight in water and slowly releases water when the soil is dry, stabilizing the soil moisture in a suitable range of 15% to 30%. This achieves gradient slow-release self-regulation of soil moisture, which is different from the passive water storage scheme of the prior art and solves the problem of uneven soil moisture in the prior art.

[0026] (2) Characteristics of the gradient water-absorbing and moisturizing material layer: The material layer is designed as a gradient structure with an upper layer of rapid water absorption (large particle size 15~20mm, high porosity ≥35%) and a lower layer of slow water release (small particle size 5~10mm, low porosity 15~35%), realizing the differentiated function of "fast absorption-slow release" and solving the problem of mutual restriction between water absorption efficiency and water release efficiency in the homogeneous structure of the existing technology.

[0027] (3) Optimization of structural layers: Based on the existing waterproof structure of green roofs, the waterproof, water-retaining and moisture-retaining performance of the overall structure is optimized by adding a layer of water-absorbing and moisture-retaining material. This reduces the soaking of water into the waterproof layer, extends the service life of the waterproof layer, and reduces the load on the drainage system.

[0028] (4) Innovation in the combination method: The water-absorbing and moisture-retaining material layer and the filter layer are combined using a "bonding + pressing" composite method, and are naturally combined with the planting soil layer using a "penetration and fusion + structural support" method. This ensures the stability of the material layer while allowing for free water transfer, without affecting soil permeability and plant root growth.

[0029] (5) Ease of construction: This invention adds only one water-absorbing and moisture-retaining material layer to the existing structure. The construction method is simple and easy to operate, requiring no additional complex equipment, thus reducing construction costs and improving construction efficiency. It has high practicality and promotional value.

[0030] The invention will now be further described with reference to the accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the present invention.

[0032] Figure label: 1. Roof structural layer; 2. Ordinary waterproof layer; 3. Thermal insulation layer; 4. Slope finding / leveling layer; 5. Root penetration resistant waterproof layer; 6. Waterproof protective layer; 7. Drainage / water storage layer; 8. Filter layer; 9. Water-absorbing and moisture-retaining material layer; 9a. Rapid water absorption layer; 9b. Slow water release layer; 10. Planting soil layer; 11. Vegetation layer; 12. Wire mesh; 13. Expansion nails. Detailed Implementation

[0033] like Figure 1 As shown, this invention discloses a moisture-releasing, self-regulating waterproof structure and construction method for green roofs, applicable to various types of green roof projects such as residential, commercial, and public buildings. It can effectively improve the waterproof performance of green roofs and the plant growth environment, promoting urban greening and environmental protection.

[0034] The structure includes the following components arranged from bottom to top: Roof structure layer 1 is the main structural layer of the building. It is preferably made of reinforced concrete roof slab, which provides stable structural support. It is required that the surface be flat, free of cracks, and the strength meet the design requirements.

[0035] Ordinary waterproof layer 2, as the second or third waterproof layer, uses high-elasticity modified bitumen waterproof membrane or polymer waterproof membrane, and is fully adhered during construction.

[0036] Insulation layer 3 uses extruded polystyrene foam board (XPS) or rigid polyurethane foam insulation board with a thermal conductivity of ≤0.030W / (m・K) to reduce heat transfer and improve the thermal insulation performance of the roof.

[0037] Leveling / slope layer 4: Use 20mm thick DSM15 mortar (1:3 cement mortar) or at least 30mm thick LC5.0 lightweight aggregate concrete to make a 2% leveling layer. This is used to level the base surface, eliminate the risk of water accumulation, and provide a good foundation for subsequent construction. The surface flatness error is ≤5mm / 2m.

[0038] Root-penetration resistant waterproof layer 5: Use chemically root-resistant modified bitumen waterproof membrane or copper-based root-penetration resistant waterproof membrane, apply with full adhesion, and overlap width ≥ 80mm to effectively prevent plant roots from penetrating the waterproof layer.

[0039] Waterproof protective layer 6, made of geotextile or polyester non-woven fabric, with a unit mass area ≥300g / m2, is fully laid on the surface of the root-penetration resistant waterproof layer to protect the root-penetration resistant waterproof layer from damage by subsequent construction processes.

[0040] Drainage / storage layer 7: Lay a 10mm~20mm high concave-convex drainage (storage) board with the convex points facing upwards and an overlap width of ≥100mm. This is used to drain or store excess water and prevent water accumulation from soaking the waterproof layer.

[0041] Filter layer 8 is made of non-woven fabric with a unit mass area ≥200g / m². It is fully laid on the surface of the drainage / storage layer with an overlap width ≥150mm to prevent fine particles in the planting soil layer from entering the drainage / storage layer and clogging the drainage channels.

[0042] Layer 9, the water-absorbing and moisture-retaining material, is the core functional layer located above the filter layer. It employs a gradient double-layer structure design to achieve gradient, slow-release self-regulation of soil moisture. This layer has a total thickness of 50-100mm. The upper layer, with larger particles, forms high-porosity water-intercepting channels, quickly diverting excess water from the planting soil to the lower layer during rainfall. The lower layer, with smaller particles, forms a capillary barrier layer, using capillary pressure to prevent further water infiltration and loss, while simultaneously using capillary action to back-permeate stored water back to the planting soil layer. The two layers work together to achieve gradient moisture management of "intercepting above and storing below, keeping the upper layer dry and the lower layer moist."

[0043] The planting soil layer 10 has a thickness of 100~300mm. Lightweight nutrient-rich planting soil with an organic matter content of ≥20% and a bulk density of ≤1.2t / m³ is selected to provide the nutrients and substrate required for plant growth.

[0044] Vegetation layer 11: Based on the roof load and greening requirements, select cold-resistant, drought-resistant, and barren-tolerant Crassulaceae plants or herbaceous plants such as Sedum lineare and Sedum sarmentosum for greening and beautification.

[0045] The water-absorbing and moisture-retaining material layer specifically includes: The upper rapid water absorption layer 9a, adjacent to the planting soil layer, is 30-60mm thick. It uses large-diameter particles, 15-20mm in diameter, with a large-pore microporous structure on the particle surface, mainly mesoporous / macroporous, with a porosity ≥35%, which can quickly absorb excess water during heavy rain or irrigation.

[0046] The lower, slow-release water layer 9b, adjacent to the filter layer, is 20-40 mm thick. It uses small-diameter particles (5-10 mm) with a high density, primarily microporous / mesoporous, with a porosity of 15-35%. This layer stores water transferred from the upper layers and slowly releases it upwards via capillary action when the soil dries. The small-diameter particles have a large specific surface area, allowing for a controllable water release rate and a continuous water supply to the plant roots.

[0047] The water-absorbing and moisture-retaining material granules are made of a composite superabsorbent resin-based material. This composite superabsorbent resin-based material uses superabsorbent resin as its core base material, and is compounded with inorganic mineral fillers, plant fiber reinforcing agents, anti-aging agents, and water-retaining agents. The mass percentage of each component is as follows: Superabsorbent resins, such as sodium / potassium polyacrylate composite resin, account for 40% to 50% and are the core water-absorbing and moisturizing components, providing high water absorption and retention capabilities.

[0048] Inorganic mineral fillers, such as diatomaceous earth / zeolite powder, account for 20%~30% to increase the porosity of the material, enhance its water adsorption and slow release capacity, and improve its strength.

[0049] Plant fiber reinforcing agents, such as coconut shell fiber / straw fiber, accounting for 10%~15%, enhance the tensile and flexural strength of materials and prevent them from breaking during construction and use.

[0050] Anti-aging agents, such as hindered phenolic antioxidants and ultraviolet absorbers, accounting for 2% to 5%, improve the weather resistance and anti-aging properties of materials and extend their service life.

[0051] Water-retaining agents, such as polyethylene glycol, at a concentration of 3% to 10%, regulate the rate of water release and improve moisturizing stability.

[0052] The components are mixed at high speed, granulated, and dried to produce granular materials of different sizes. The upper layer of particles has a diameter of 15-20 mm and is mainly composed of mesopores / macropores; the lower layer of particles has a diameter of 5-10 mm and a microporous structure on the particle surface, mainly composed of micropores / mesopores. This ensures both rapid water absorption and slow water release.

[0053] Physical properties that absorbent and moisture-retaining materials must meet: Saturation absorption ≥500g / g (deionized water); ≥300g / g (tap water) Water absorption speed Upper layer: ≤30min (to reach 90% saturation water absorption); Lower layer: ≤60min (to reach 90% saturation water absorption) Water retention rate ≥80% (25℃, stand for 24 hours); ≥50% (25℃, stand for 72 hours) Acid and alkali resistance Within a pH range of 4 to 10, the water absorption retention rate is ≥90%. Anti-aging properties After 1000 hours of accelerated artificial aging, the water absorption performance retention rate is ≥85%. Chemical properties: 1) pH: Neutral, pH 6.5~7.5, will not change the acidity or alkalinity of the planting soil, suitable for the growth of various plants; 2) Ionic stability: The gel formed after absorbing water does not swell or decompose, and no harmful ions are released. It has no corrosive effect on plant roots. 3) Compatibility: It has good compatibility with planting soil, plant fibers, geotextiles and other materials, does not react chemically, and does not affect soil aeration and permeability.

[0054] The water-absorbing and moisture-retaining material layer prepared according to the above ratio has the following characteristics: (1) High water absorption: It can absorb 500 to 1000 times its own weight in deionized water and reach saturation within 30 to 60 minutes, effectively storing excess rainwater and irrigation water. The volume expansion rate after water absorption is ≤200%, preventing the waterproof layer from being damaged by compression.

[0055] (2) Slow release: When the soil moisture content is below 15%, the stored water is released slowly. The release rate is controllable, continuously supplying water to the plant roots and maintaining the soil moisture in the suitable range of 15% to 30%.

[0056] (3) Gradient moisture management: the upper layer with large particles absorbs water quickly, while the lower layer with small particles releases water slowly, thus achieving a differentiated function of fast absorption and slow release.

[0057] (4) Durability: The material has good acid and alkali resistance and anti-aging properties. Its performance is stable in the temperature range of -30℃ to 80℃. The design service life is ≥15 years. It can maintain stable water absorption and moisture retention properties during long-term use.

[0058] (5) Environmental protection: The material is non-toxic, harmless and non-irritating, meets the requirements of the "Green Building Evaluation Standard" GB / T 50378, will not have a negative impact on plant growth and ecological environment, and can be recycled and will not generate construction waste in the later stage.

[0059] (6) Puncture resistance: The material has a dry compressive strength ≥0.5MPa and a wet compressive strength ≥0.3MPa. It has a certain physical strength and can buffer the puncture force of plant roots and help protect the lower waterproof layer.

[0060] Furthermore, the bottom surface of the absorbent and moisture-retaining material layer is connected to the filter layer via an adhesive layer, and a wire mesh 12 is laid on the top surface. The wire mesh is connected to the filter layer via expansion nails 13, and the absorbent and moisture-retaining material is fixed to the filter layer by pressing and covering it with the wire mesh. The mesh size of the wire mesh is smaller than the particle size of large-diameter particles; in this embodiment, it is 10mm × 10mm, the overlap width of the wire mesh is ≥100mm, and it is fixed with plastic expansion nails with a fixing point spacing ≤500mm × 500mm. The combination of "adhesion + pressing" ensures a tight fit between the absorbent and moisture-retaining material layer and the filter layer, preventing displacement or sliding during construction and use.

[0061] This application adopts a natural combination of "penetration and fusion + structural support" to ensure the free transfer of water between the two layers, while not affecting plant root growth and soil permeability: 1) Penetration and integration: The water-absorbing and moisturizing material layer has a granular porous structure. After the planting soil layer is laid on its surface, the planting soil will naturally seep into the gaps between the material particles to form a "soil-material" penetration and integration layer. This ensures that water can be quickly absorbed from the planting soil layer to the material layer, and also allows the material layer to slowly release water to the planting soil layer. 2) Structural support: The compressive strength of the water-absorbing and moisture-retaining material particles can support the load of the planting soil layer and plants, preventing the planting soil layer from sinking and blocking the drainage (storage) layer; at the same time, the gaps between the material particles maintain a porosity of ≥10%, ensuring the air permeability of the planting soil layer and providing space for plant roots to breathe. 3) Root adaptation: The particle size of the material is 5~20mm, and the plant roots can grow through the gaps between the particles. They are not blocked by the material layer and can directly absorb the water released by the material layer, thus improving the plant's water absorption efficiency.

[0062] The construction method includes the following steps: Step 1: Roof structural layer treatment: Clean the surface of the reinforced concrete roof panel to remove scum, dust, oil and other impurities. Repair surface cracks with epoxy resin mortar to ensure that the base layer is flat and firm.

[0063] Step 2: Construction of ordinary waterproof layer: Fully adhere high-elasticity modified bitumen waterproof membrane or polymer waterproof membrane, with an overlap width of ≥80mm. Strengthen the joints at internal and external corners, drain outlets and other nodes. After construction, conduct a water tightness test. The water tightness height should be ≥20mm and the water tightness time should be ≥24h. No leakage is acceptable.

[0064] Step 3: Insulation layer construction: Fully lay insulation boards on the surface of the ordinary waterproof layer, with the insulation boards tightly spliced ​​together and the gaps filled with insulation strips of the same material. Use the dry-laying method to avoid damaging the waterproof layer.

[0065] Step 4: Slope / Leveling Layer Construction: Use 20mm thick DSM15 mortar (1:3 cement mortar) or LC5.0 lightweight aggregate concrete to make a 2% slope layer. Use a level to control the slope, compact it with a plate vibrator, level the surface with a scraper, and cure for 3~5 days. The surface flatness error should be ≤5mm / 2m.

[0066] Step 5: Construction of root-penetration resistant waterproof layer: Fully adhere chemical root-resistant modified bitumen waterproof membrane or copper-based root-penetration resistant waterproof membrane, with an overlap width ≥ 80mm, and reinforce the joints. After construction, conduct a water tightness test again. No leakage after 24 hours is considered qualified.

[0067] Step 6: Waterproof protective layer construction: Fully cover the area with geotextile or polyester non-woven fabric with a unit weight area ≥300g / m², with an overlap width ≥100mm, and fix it by spot bonding to avoid hollow spots and wrinkles.

[0068] Step 7: Drainage / storage layer construction: Lay 10~20mm high-concave-convex drainage / storage boards with the convex points facing upwards, and the overlap width ≥100mm. The drainage boards should be tightly connected to the parapet wall of the roof, the drain outlet, and other nodes to ensure smooth drainage.

[0069] Step 8: Filter layer construction: Fully cover the non-woven fabric with a unit mass area ≥200g / m², with an overlap width ≥150mm. Fold the edges of the non-woven fabric to the inside of the parapet wall, with a height ≥ the thickness of the planting soil layer to prevent the planting soil from being lost.

[0070] Step 9: Application of the water-absorbing and moisture-retaining material layer: ① Adhesive application: Use a sprayer or brush to evenly apply water-based acrylic adhesive to the surface of the filter layer. The application amount is 0.2~0.3kg / m², and the application area is fully covered without any missed spots or adhesive buildup. ② Material laying: After the adhesive is surface dry (10~20min), the water-absorbing and moisture-retaining material granules are evenly laid on the surface. First lay the lower layer, then lay the upper layer. The surface is smoothed with a scraper to ensure uniform thickness with an error of ≤5mm. ③ Light pressure fixing: Use a flat plate to lightly press the material layer to fully bond the material particles with the adhesive. The light pressure should be light enough not to break the material particles. ④ Steel wire mesh laying: Fully lay 10mm×10mm welded steel wire mesh on the surface of the material layer, with wire diameter ≥1.2mm, overlap width ≥100mm, and fix with plastic expansion nails. The fixing point spacing is ≤500mm×500mm, and the fixing point spacing around the parapet wall is increased to ≤300mm. ⑤ Material acceptance: After construction is completed, check the thickness, flatness and wire mesh fixation of the material layer to ensure that there is no material loss, no hollow areas and no displacement.

[0071] Step 10: Planting soil layer construction: Lay a 100~300mm thick layer of lightweight nutrient planting soil on the surface of the water-absorbing and moisture-retaining material layer. The soil should be laid in layers, with each layer ≤100mm thick. Lightly compact the soil to avoid breaking the water-absorbing and moisture-retaining material layer due to vibrating too much. The surface of the planting soil layer should be sloped according to the design requirements to eliminate the risk of water accumulation.

[0072] Step 11: Vegetation layer construction: Plant vegetation by broadcasting, laying, or dividing according to design requirements. Water thoroughly after planting to help the roots establish. The amount of water should be enough to saturate the soil layer to ensure the survival rate of the plants.

[0073] Step 12: Post-construction maintenance: After construction is completed, a 15-day maintenance period will be carried out. Water once a day for the first 7 days and water once every 3 days for the next 8 days. At the same time, check the roof waterproofing, water-absorbing and moisture-retaining material layer, drainage system and other parts, and deal with any problems in time.

[0074] Key construction operation points 1) Key points for waterproofing construction: Before constructing ordinary waterproofing layers and root-penetration resistant waterproofing layers, the substrate must be dry and flat; the overlap width of the roll material and the reinforcement treatment of the joints must meet the specifications; a water tightness test must be carried out after each waterproofing layer is constructed to ensure that there is no leakage.

[0075] 2) Key points for the construction of the water-absorbing and moisture-retaining material layer: ① The adhesive should be applied evenly and allowed to dry slightly before laying the material to avoid poor adhesion between the material and the adhesive; ② The thickness of the material must be strictly controlled. If it is too thin, it will affect the water absorption and retention effect; if it is too thick, it will increase the roof load. ③ The wire mesh must be securely fixed to prevent rainwater erosion or planting construction from causing the material layer to shift or be lost; ④ The water-absorbing and moisture-retaining material should be stored in a dry environment and should be kept dry during construction. If it rains during construction, it should be covered with a rainproof cloth in time to prevent the material from absorbing water in advance and affecting the construction.

[0076] 3) Key points for planting soil layer construction: Lightweight nutrient soil should be used for planting soil, and heavy clay should be avoided to prevent increasing the roof load; avoid heavy rolling during laying to prevent damage to the water-absorbing and moisture-retaining material layer and the waterproof layer.

[0077] 4) Key points for joint construction: At joints such as parapet walls, drain outlets, and ventilation openings, the water-absorbing and moisture-retaining material layer must be tightly sealed, the wire mesh must extend to the inside of the joint, and the filter layer and non-woven fabric must be folded to a sufficient height to prevent the loss of planting soil and rainwater backflow.

[0078] This application has the following advantages over the prior art: 1. Prevent plant roots from penetrating the waterproof layer: (1) Technical problem: The present invention aims to reduce the soaking of water in the waterproof layer by adding a layer of water-absorbing and moisturizing material, while buffering the piercing force of plant roots, thereby effectively protecting the waterproof layer and preventing plant roots from penetrating the waterproof layer.

[0079] (2) Solution: The water-absorbing and moisturizing material layer can absorb excess water, reduce the long-term soaking of the waterproof layer by water, and at the same time buffer the piercing force of plant roots to a certain extent, thus protecting the integrity of the waterproof layer.

[0080] 2. Reduce water immersion and extend the life of the waterproof layer: (1) Technical problem: The present invention aims to absorb excess water through the water-absorbing and moisturizing material layer, reduce the long-term immersion of water in the waterproof layer, and thus extend the service life of the waterproof layer.

[0081] (2) Solution: The water-absorbing and moisture-retaining material layer can absorb and store excess water, reducing the long-term immersion of the waterproof layer by water and effectively extending the service life of the waterproof layer.

[0082] 3. Maintain even soil moisture to promote healthy plant growth: (1) Technical problem: The present invention aims to absorb excess water through a water-absorbing and moisturizing material layer and release it slowly when the soil is dry, thereby maintaining the uniformity of soil moisture and promoting healthy plant growth.

[0083] (2) Solution: The water-absorbing and moisture-retaining material layer can absorb excess water and release it slowly when the soil is dry, maintaining the uniformity of soil moisture and providing a good growing environment for plants.

[0084] 4. The absorbent layer is divided into upper and lower layers to achieve gradient moisture management: (1) Technical problem: The existing water-absorbing material layer is mostly of uniform structure, which cannot achieve the differentiated function of "rapid water absorption and slow water release", resulting in mutual restriction between water absorption efficiency and water release efficiency.

[0085] (2) Solution: The present invention designs the water-absorbing and moisturizing material layer as a gradient double-layer structure - the upper layer is a fast water-absorbing layer (large particle size, 15~20mm, high porosity), and the lower layer is a slow water-releasing layer (small particle size, 5~10mm, high density), realizing gradient moisture management by quickly capturing excess moisture in the upper layer and slowly releasing water in the lower layer.

[0086] 5. Simplify construction and reduce construction costs: (1) Technical problem: The present invention aims to simplify the construction method and reduce the construction cost by adding a layer of water-absorbing and moisture-retaining material on the basis of the existing structure.

[0087] (2) Solution: Add a layer of water-absorbing and moisture-retaining material to the existing structure. The construction method is simple and easy to operate, which reduces the construction cost and improves the construction efficiency.

[0088] 6. Reduce the burden on the drainage system: (1) Technical problem: The present invention aims to absorb excess rainwater through a water-absorbing and moisture-retaining material layer, thereby reducing the amount of rainwater that flows directly into the drainage system and alleviating the burden on the drainage system.

[0089] (2) Solution: The water-absorbing and moisture-retaining material layer can absorb excess rainwater, reduce the amount of rainwater flowing directly into the drainage system, reduce the burden on the drainage system, and improve the efficiency of the drainage system.

[0090] This application utilizes an innovative gradient double-layer structure technology to achieve gradient slow-release self-regulation of soil moisture in green roofs, rather than the passive water storage and slow release of existing technologies. This improves the waterproof performance of green roofs and the plant growth environment. At the same time, the self-regulating humidity function of this invention can significantly reduce the amount of water needed for plant irrigation, reduce the risk of water erosion of the waterproof layer, thereby improving the waterproof effect of green roofs and extending their waterproof lifespan. It has significant practicality and innovation.

[0091] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A moisture-releasing, self-regulating waterproof structure for green roofs, characterized in that, The roof structure layer (1), ordinary waterproof layer (2), thermal insulation layer (3), slope / leveling layer (4), root penetration resistant waterproof layer (5), waterproof protective layer (6), drainage / water storage layer (7), filter layer (8), water-absorbing and moisture-retaining material layer (9), planting soil layer (10), and vegetation layer (11) are arranged from bottom to top. The water-absorbing and moisturizing material layer (9) is composed of a gradient double-layer structure of water-absorbing and moisturizing material particles. The upper layer is a fast water-absorbing layer (9a) and the lower layer is a slow water-releasing layer (9b). The fast water-absorbing layer (9a) is composed of large-diameter water-absorbing and moisturizing material particles forming a high-porosity water-blocking channel; the slow water-releasing layer (9b) is composed of small-diameter water-absorbing and moisturizing material particles forming a capillary barrier.

2. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 1, characterized in that, The particle size of large-particle water-absorbing and moisturizing material is 15~20mm, while the particle size of small-particle water-absorbing and moisturizing material is 5~10mm.

3. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 2, characterized in that, The porosity of large-particle-size water-absorbing and moisturizing material particles is ≥35%, while the porosity of small-particle-size water-absorbing and moisturizing material particles is 15%~35%.

4. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 1, characterized in that, The water-absorbing and moisturizing material particles are made of a composite superabsorbent resin-based material.

5. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 4, characterized in that, The composite superabsorbent resin-based material includes superabsorbent resin, inorganic mineral filler, plant fiber reinforcing agent, anti-aging agent, and water-retaining agent.

6. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 5, characterized in that, The mass percentages of each component in the composite superabsorbent resin-based material are as follows: superabsorbent resin: 40%-50%; inorganic mineral filler: 20%-30%; plant fiber reinforcing agent: 10%-15%; anti-aging agent: 2%-5%; water-retaining agent: 3%-10%.

7. The humidity-controlled, self-regulating waterproof structure for a green roof according to claim 1, characterized in that, The bottom surface of the water-absorbing and moisturizing material layer (9) is connected to the filter layer (8) through an adhesive layer, and a wire mesh (12) is laid on the top surface. The wire mesh (12) is connected to the filter layer (8) through expansion nails (13). The water-absorbing and moisturizing material is pressed and fixed on the filter layer (8) by the wire mesh (12).

8. The humidity-controlled self-regulating waterproof structure for a green roof according to claim 1, characterized in that, The thickness of the rapid water absorption layer (9a) is 30-60 mm, and the thickness of the slow water release layer (9b) is 20-40 mm.

9. A construction method for a moisture-releasing, self-regulating waterproof structure for a green roof as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Roof structural layer (1) treatment, cleaning impurities and repairing cracks; Step 2: Construction of ordinary waterproof layer (2); Step 3: Construction of the insulation layer (3); Step 4: Construction of the slope / leveling layer (4); Step 5: Construction of the root-penetration resistant waterproof layer (5); Step 6: Construction of the waterproof protective layer (6); Step 7: Construction of drainage / storage layer (7); Step 8: Construction of filter layer (8); Step 9: Construction of the water-absorbing and moisture-retaining material layer (9): Apply adhesive to the surface of the filter layer (8), lay water-absorbing and moisture-retaining material granules, scrape flat, press the water-absorbing and moisture-retaining material granules to make the granules fully bond with the adhesive, fully cover the top surface of the water-absorbing and moisture-retaining material granules with wire mesh (12), and connect the wire mesh (12) to the filter layer (8) with expansion nails (13), and press and fix the water-absorbing and moisture-retaining material onto the filter layer (8) through the wire mesh (12); Step 10: Construction of the planting soil layer (10); Step 11: Construction of the vegetation layer (11).

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