Construction method of engineering slag base temporary building road structure for site office living area

Abstract

This invention discloses a temporary road structure and construction method for construction site office and living areas based on engineering waste soil. The structure includes, from bottom to top, a seepage-proof drainage layer, a compacted waste soil base layer, and a permeable pavement layer. The seepage-proof drainage layer is laid on the foundation soil. The seepage-proof drainage layer, from top to bottom, includes a seepage-proof layer and a drainage layer, with both sides of the drainage layer connected to the site's drainage ditch. At least two horizontally laid drainage geogrids are installed within the compacted waste soil base layer, with waste soil backfilling between adjacent drainage geogrid layers. Adjacent drainage geogrid layers are connected by vertical ribbed geogrids, forming an integrated three-dimensional drainage reinforcement network. The permeable pavement layer, from bottom to top, includes a support layer and a permeable brick layer. This invention relates to the field of building construction technology and can solve the technical problems existing in the prior art.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a temporary road structure and construction method for construction site office and living areas based on engineering waste soil. Background Technology

[0002] Temporary roads at construction sites are typically categorized into production and transportation roads for heavy vehicles and light-duty roads for use within office and living areas, based on their function and load requirements. The latter, while not designed to withstand heavy loads, often simply adopt the high standards of the former, leading to material waste, increased costs, extended construction periods, and unnecessary carbon emissions. Furthermore, the large amounts of construction waste and demolition debris generated at construction sites are traditionally disposed of primarily through off-site transportation, resulting in low resource utilization, high disposal costs, and potential environmental pollution. Roads in office and living areas also need to address issues such as softening of the base layer during the rainy season, muddy and frost-prone surface layers, and frequent maintenance. In addition, common temporary roads suffer from difficulties in recycling after demolition, low turnover rates, and large amounts of waste generation. Therefore, there is an urgent need to develop a new type of temporary road system suitable for light-load areas, capable of resource utilization of construction waste and demolition debris, possessing good drainage and deformation resistance, and supporting rapid assembly and recycling.

[0003] Currently, temporary roads at construction sites mainly employ the following methods: First, rigid or semi-rigid integral hardening, such as cast-in-place low-grade concrete or cement-stabilized crushed stone base; second, laying graded crushed stone combined with a single layer of geotextile or geogrid to reinforce the foundation; third, assembling and laying steel temporary road slabs or precast concrete slabs; fourth, using recycled materials (such as milled asphalt and crushed concrete) for loose laying and compaction; and fifth, using conventional permeable bricks for dry laying or mortar paving in pedestrian areas. These existing construction methods present the following technical problems:

[0004] (1) Low resource utilization and high carbon emissions. Current practices generally rely on newly purchased cement, natural aggregates or finished boards, with extremely low utilization rates of engineering waste and construction waste generated on site, failing to achieve on-site resource recycling, and resulting in large carbon emissions during material transportation and production processes.

[0005] (2) The structure has a single function and insufficient drainage and deformation resistance. In conventional practices, the functions of seepage prevention, drainage and reinforcement are disconnected. In particular, the planar reinforcement method is difficult to form a three-dimensional drainage network. After water seepage, the base layer is prone to grouting, grouting and uneven settlement.

[0006] (3) Poor reusability and recyclability. Cast-in-place structures generate construction waste after demolition, precast slabs have low recycling efficiency and high damage rate, and traditional permeable bricks are easily clogged and damaged and lack systematic recycling design, making it difficult to meet the needs of repeated reuse.

[0007] (4) Poor permeability and anti-clogging performance. Ordinary permeable bricks have simple pore structure and single gradation, lacking hydrophobic design and hierarchical pore organization. They are prone to clogging due to fine particle migration during use, resulting in poor water permeability.

[0008] (5) The construction is complex, the cycle is long and the degree of assembly is low. Existing processes rely heavily on on-site wet operations and heavy compaction. There are many construction steps and low efficiency. The structure design lacks modularity, lightweight and rapid assembly, making it difficult to achieve "quick assembly and quick disassembly".

[0009] Therefore, there is a need to provide a temporary road structure and construction method for construction waste soil base in construction site office and living areas, which can solve the above-mentioned technical problems. Summary of the Invention

[0010] The purpose of this invention is to provide a temporary road structure and construction method for construction site office and living areas based on construction waste soil, which can solve the above-mentioned technical problems.

[0011] This invention is implemented as follows:

[0012] A temporary road structure for construction site office and living areas based on construction waste soil includes, from bottom to top, a seepage-proof drainage layer, a compacted waste soil base layer, and a permeable pavement layer. The seepage-proof drainage layer is laid on the foundation soil. The seepage-proof drainage layer, from top to bottom, includes a seepage-proof layer and a drainage layer, with both sides of the drainage layer connected to the drainage ditch of the construction site. At least two horizontally laid drainage geogrids are installed within the compacted waste soil base layer, with waste soil backfilled between adjacent drainage geogrid layers. Adjacent drainage geogrid layers are connected by vertical ribbed geogrids, forming an integrated three-dimensional drainage reinforcement network. The permeable pavement layer, from bottom to top, includes a support layer and a permeable brick layer.

[0013] The impermeable layer is made of HDPE geomembrane with non-woven geotextile protective layers on both sides; the laying width of the HDPE geomembrane covers the construction area of ​​the temporary road structure on the construction site and the drainage ditches on both sides.

[0014] The drainage layer is composed of recycled fine aggregate obtained from the crushing of building demolition waste, serving as a water collection layer for the compacted slag base and connected to the water collection ditches on both sides.

[0015] The surface of the drainage geogrid and the vertical ribbed bar geogrid is provided with micropores, and several drainage channels are arranged in the transverse and longitudinal directions in the inner surface. Several drainage channels are slightly raised along the length direction to form microchannels for seepage flow.

[0016] The vertical ribbed geogrid has C-shaped latches at both ends, and back-locking seams are formed at the two ends of the vertical ribbed geogrid. Several stepped toothed raised ribs are formed at intervals on the vertical ribbed geogrid between the back-locking seams and the C-shaped latches, so that the two ends of the vertical ribbed geogrid are mechanically self-locked with the two adjacent drainage geogrids through the back-locking structure of C-shaped latches-back-locking seams-stepped toothed raised ribs.

[0017] The supporting layer is a subbase made of recycled fine aggregate obtained from the crushing of building demolition waste;

[0018] The permeable brick layer is made of permeable bricks; the permeable bricks are based on engineering waste soil and are formed by layered material distribution and wet jointing and wet co-pressing. From top to bottom, the permeable bricks consist of an upper hydrophobic infiltration layer, a middle load-bearing skeleton layer, and a bottom capillary fracture layer. The upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer form a pore network that runs through the entire structure from top to bottom. The permeable bricks are provided with a U-shaped high-strength nylon frame around their perimeter. Adjacent permeable bricks can be detachably spliced ​​by spring locks through the U-shaped high-strength nylon frame. The U-shaped high-strength nylon frame is embedded with a polyurethane buffer strip.

[0019] The interconnected porosity of the upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer decreases sequentially, as does the characteristic pore size; the upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer form a pore network that runs from top to bottom; the surface contact angle of the bottom capillary fracture layer is not less than 105°.

[0020] The permeable bricks are composed of the following raw materials: engineering waste soil, waste concrete hydrophobic powder, alkali-activated cementitious material, and admixtures; wherein, the total amount of engineering waste soil is 55-70%, which is screened and dewatered, with a moisture content not exceeding 15% and a particle size not exceeding 4mm; the total amount of alkali-activated cementitious material is 25-35%, composed of solid and liquid components in a mass ratio of 3:2, wherein the solid component is a 1:1 mixture of sulfoaluminate cement clinker powder and S95 grade slag powder, and the liquid component is a 2:1 mixture of water glass with a modulus of 1.8 and a 10% concentration of NaOH solution, with a modulus of 1.6-2.0; the total amount of admixtures is 0.8-1.5%, including 0.5-0.9% polycarboxylate superplasticizer, 0.2-0.4% shrinkage reducer, and 0.1-0.3% stabilizer; and the total amount of waste concrete hydrophobic powder is 0.3-0.6%.

[0021] A construction method for a temporary road structure based on construction waste soil in a construction site office and living area includes the following steps:

[0022] Step 1: Construction of the seepage prevention and drainage layer;

[0023] The site for the temporary road structure to be constructed was excavated and leveled. Then, a non-woven geotextile, an HDPE geomembrane, and an upper non-woven geotextile were laid on the foundation soil to form a seepage barrier layer, and counter-pressure was applied on both sides for fixation. Then, recycled fine aggregate made from demolition waste was spread on the seepage barrier layer to form a drainage layer.

[0024] Step 2: Compact the soil base layer in layers;

[0025] Based on the design height of the compacted slag base, the slag backfill area is divided into 1 to n small areas from bottom to top. Each small area has the same height, and the slag backfilling construction of the n small areas is carried out in layers from bottom to top.

[0026] Step 3: Construction of permeable pavement layer;

[0027] On top of the compacted slag base, recycled fine aggregate obtained from the crushing of building demolition waste is spread as a support layer. Permeable bricks are then dry-laid on the support layer in a herringbone pattern to form a permeable brick layer. The edges of adjacent permeable bricks are constrained by spring locks through a U-shaped high-strength nylon frame with polyurethane buffer strips embedded on the inside.

[0028] In step 1, the width W of the impermeable layer covers the bottom of the temporary road and the entire surface of the drainage ditch on both sides, and is horizontally folded back at the top of the drainage ditch to form a horizontal fold section.

[0029] The laying width W of the impermeable layer is calculated using the following formula:

[0030]

[0031] In the formula: W 防渗 w1 is the width of the impermeable layer; w1 is the width of the horizontal bend at the top of the reserved drainage ditch, 1.0m≤w1≤1.5m; h g Here, h represents the excavation depth and the height of the drainage ditch; 0.4m ≤ h. g ≤0.6m; w g The width of the bottom of the drainage ditch is 0.5m ≤ w g ≤0.8m; W R θ represents the bottom width of the temporary road structure; θ represents the slope of both sides of the temporary road structure, and the slope of the drainage ditch is the same as that of the temporary road structure. 45°≤θ≤72°, that is, the slope ratio is between 1:1 and 1:0.33.

[0032] In step 2, the construction process for backfilling the slag in each small area is as follows: laying drainage geogrid at the bottom of the small area → locking the bottom of the vertical ribbed geogrid → backfilling and compacting the first layer of slag → excavating the anchoring trench at the edge of the first layer of compacted slag → folding back and anchoring the bottom drainage geogrid edge → backfilling and compacting the slag within the remaining height → laying drainage geogrid at the top → locking the top of the vertical ribbed geogrid; wherein, the drainage geogrid laid at the top in the (n-1)th small area also serves as the drainage geogrid at the bottom in the nth small area, thus completing the layered construction of the compacted slag base layer;

[0033] Specifically, the initial backfill height of the first layer of slag in each small area is h1. Then, an anchoring trench with a depth of h' and a width of w' is excavated at a horizontal distance h2 from the edge of this slag layer. The bottom drainage geogrid is then folded back at an angle θ on both sides and buried in the anchoring trench. Multiple U-shaped nails are used to fix the trench at intervals along the length of the temporary road structure at the top and bottom of both sides of the slope, and at the center of the trench bottom. The anchoring trench is then backfilled and compacted to form a stable mechanical interlocking structure. The laying width W of each layer of drainage geogrid is calculated using the following formula:

[0034]

[0035] In the formula: h1 is the backfill height of the first layer of slag in the small area, 0.2m≤h1≤0.5m; w is the bottom width of the first layer of backfill slag in the small area; h2 is the horizontal distance from the outer side of the anchoring trench to the edge of the first layer of slag, 0.5m≤h2≤1.0m; h' is the depth of the anchoring trench, 0.2m≤h'≤0.3m; w' is the width of the anchoring trench, 0.5m≤w'≤0.8m; θ is the slope of both sides of the temporary road structure; α is the slope of both sides of the anchoring trench, α≤θ;

[0036] In step 2, the horizontal and vertical spacing of the vertical rib strip grid is d, 0.5m≤d≤1.0m. At the same time, the joints of the vertical rib strip grids of the upper and lower layers should be staggered alternately, with a stagger distance of 0.5d.

[0037] In step 2, the backfilling of the slag is carried out by layered backfilling and compaction. The backfilling height h1 of the first layer of slag must meet the requirement of 0.2m≤h1≤0.5m. The backfilling height of each layer of slag within the remaining height is 0.15~0.2m. The compaction degree of the backfilled slag is not less than 95%.

[0038] The preparation process of the permeable bricks includes the following steps:

[0039] S3-1: After dewatering the construction waste soil to within 15%, it is sieved into 2~4mm coarse aggregate, 0.6~1.2mm fine aggregate, and 0.15~0.6mm fine powder for later use. These are then premixed into three types of soil materials, A, B, and C, according to the following mass ratios: coarse aggregate: fine aggregate = 4:6, coarse aggregate: fine aggregate: fine powder = 3:6:1, and coarse aggregate: fine aggregate: fine powder = 2:7:1.

[0040] S3-2: Put the three types of soil materials A, B and C into the mixer respectively, spray in the liquid component of the alkali-activated cementitious material and wet mix for 60 seconds, then add the solid component of the alkali-activated cementitious material and mix for 90 seconds to obtain three kinds of mixtures. Among them, waste concrete hydrophobic micro powder needs to be added when mixing the soil material of type C.

[0041] S3-3: In the mold, the material is laid in layers. The bottom layer is laid first to form the bottom capillary fracture layer, the middle layer is laid later to form the middle load-bearing skeleton layer, and the top layer is laid last to form the top hydrophobic infiltration layer. The interval between each layer is no more than 2 minutes. Before laying the middle layer, a 1-2 mm shallow toothed interface is formed on the surface of the bottom capillary fracture layer.

[0042] The mix proportions of the upper hydrophobic infiltration layer are as follows: Class A soil accounts for 58-66%, alkali-activated cementitious materials account for 28-34%, and admixtures account for 0.8-1.2%.

[0043] The mix proportions for the intermediate load-bearing skeleton layer are: 60-70% Class B soil, 25-32% alkali-activated cementitious materials, and 0.8-1.2% admixtures;

[0044] The mix proportions for the bottom capillary fracture layer are: 55-65% Class C soil, 30-35% alkali-activated cementitious materials, 0.8-1.2% admixtures, and 0.3-0.6% waste concrete hydrophobic powder;

[0045] S3-4: After the material is laid, a three-stage equal pressure and low-amplitude micro-vibration process is used to make bricks. The initial pressure is 5MPa and held for 10s to position the coarse aggregate. The main pressure is 15MPa and held for 20s to force the fine aggregate to fill the gaps between the coarse aggregate. The final pressure is 20MPa and held for 10s to compact the interface transition zone. During the three-stage equal pressure process, the micro-vibration frequency is 20~40Hz and the displacement amplitude is ≤0.4mm.

[0046] S3-5: Steam curing with mold for 24 hours at 80℃ and ≥95% humidity, followed by natural curing for 5 days after demolding.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] 1. This invention constructs an integrated three-dimensional drainage reinforcement network by utilizing vertical infiltration channels in the permeable pavement layer, in-plane drainage channels in the compacted slag soil base layer's drainage geogrid, vertical collection channels in the same material's vertically ribbed geogrid, and a drainage layer connected to the side drainage ditches. This forms a closed infiltration path: infiltration → in-plane drainage → vertical collection → bottom collection → external drainage through side ditches. Unlike single horizontal or vertical drainage, this integrated three-dimensional drainage reinforcement network significantly shortens the equivalent drainage path and increases the number of drainage boundaries. The pore water pressure inside the slag soil dissipates rapidly, effective stress is increased promptly, drainage consolidation rate is accelerated, and early strength improvement is more significant, providing earlier bearing conditions for the paving and passage of temporary road structures. In addition, when surface water infiltrates, the water first passes through the permeable pavement layer and enters the in-plane microchannels of the drainage geogrid to achieve rapid diversion. Then, it flows down along the in-plane microchannels of the vertical ribbed geogrid to the drainage layer and is continuously discharged to the lateral collection ditch. The whole process is characterized by unobstructed water flow, low resistance, and no risk of water stagnation or backflow.

[0049] 2. This invention reuses construction demolition waste, waste concrete hydrophobic powder, and engineering spoil from the construction site, greatly reducing the reliance on newly purchased cement, natural aggregates, and finished panels, achieving on-site resource recycling, and reducing carbon emissions during material transportation and production.

[0050] 3. In this invention, adjacent permeable bricks are constrained at the edges by a U-shaped high-strength nylon frame with an embedded polyurethane buffer strip on the inner side, secured by spring latches. The polyurethane buffer strip absorbs the impact energy of vehicle tires, preventing rigid collisions from causing the edges and corners of the permeable bricks to crack. The elastic deformation of the polyurethane buffer strip allows the permeable bricks to expand and contract due to temperature changes, eliminating internal stress concentration. The rigid frame formed by the U-shaped high-strength nylon resists the horizontal slippage force caused by vehicle eccentric loading. The spring latch structure can be quickly unlocked during the demolition and reuse of temporary road structures, enabling rapid recycling of the permeable pavement layer and meeting the efficiency requirements of modular road reuse. Attached Figure Description

[0051] Figure 1 This is a structural schematic diagram of the temporary road structure based on construction waste soil used in the construction site office and living area of ​​this invention;

[0052] Figure 2 This is a schematic diagram of the compacted soil base layer in the temporary road structure of the construction site office and living area of ​​the present invention.

[0053] Figure 3 This is a partial structural schematic diagram of the vertical ribbed grid in the temporary road structure based on construction waste soil for the construction site office and living area of ​​the present invention.

[0054] Figure 4 This is a schematic diagram of the laying of the anti-seepage layer in the temporary road structure based on construction waste soil in the construction site office and living area of ​​this invention;

[0055] Figure 5 This is a schematic diagram of the drainage geogrid and the first layer of backfill soil at the bottom of a small area in the temporary road structure based on construction waste soil in the construction site office and living area of ​​this invention.

[0056] In the figure, there is an impermeable layer 11, a drainage layer 12, a horizontal fold section 13, a drainage geogrid 21, a vertical ribbed strip geogrid 22, a C-shaped tongue 23, a back-lock joint 24, a stepped toothed raised rib 25, slag 26, an anchoring ditch 27, a support layer 31, a permeable brick layer 32, foundation soil 4, and a drainage ditch 5. Detailed Implementation

[0057] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0058] Please see the appendix Figure 1 A temporary road structure for construction site office and living areas based on construction waste soil includes, from bottom to top, a seepage-proof drainage layer, a compacted waste soil base layer, and a permeable pavement layer. The seepage-proof drainage layer is laid on the foundation soil 4. The seepage-proof drainage layer includes, from top to bottom, a seepage-proof layer 11 and a drainage layer 12. The two sides of the drainage layer 12 are connected to the drainage ditch 5 of the construction site. At least two layers of horizontally laid drainage geogrids 21 are installed in the compacted waste soil base layer. Waste soil 26 is backfilled between two adjacent drainage geogrids 21, and the two adjacent drainage geogrids 21 are connected by vertical ribbed geogrids 22 to form an integrated three-dimensional drainage reinforcement network. The permeable pavement layer includes, from bottom to top, a support layer 31 and a permeable brick layer 32.

[0059] The impermeable layer 11 is made of HDPE geomembrane with non-woven geotextile protective layers on both sides; the laying width of the HDPE geomembrane covers the construction area of ​​the temporary road structure on the construction site and the drainage ditches 5 on both sides.

[0060] Preferably, the thickness of the HDPE geomembrane is 1.0~1.5mm, and adjacent HDPE geomembranes are joined by hot-melt overlap, with an overlap width of not less than 100mm. The basis weight of the non-woven geotextile protective layer is 300g / m². 2 It can isolate fine materials and prevent damage to the HDPE geomembrane from sharp objects on the substrate and construction scratches. The structure composed of the lower non-woven geotextile, HDPE geomembrane, and upper non-woven geotextile can prevent the foundation soil from gushing and turning muddy under the action of the upper load.

[0061] The drainage layer 12 is composed of recycled fine aggregate obtained from the crushing of building demolition waste, serving as a water collection layer for the compacted slag base and connected to the water collection ditches 5 on both sides.

[0062] Preferably, the thickness of the drainage layer 12 is 50~80mm.

[0063] The drainage geogrid 21 and the vertical ribbed bar geogrid 22 are provided with micropores on their surfaces and have several drainage channels arranged horizontally and vertically in their surfaces. The drainage channels are slightly raised along their length to form microchannels for water infiltration.

[0064] Preferably, the vertical ribbed geogrid 22 is made by cutting the same type of geogrid sheet as the drainage geogrid 21. The drainage geogrid 21 has a transverse and longitudinal tensile strength of not less than 30kN / m, and the micropores on its surface have a pore size of 1~2mm, which can promote water-soil interface infiltration.

[0065] Please see the appendix Figure 2 and attached Figure 3 The vertical ribbed grid 22 has C-shaped latches 23 at both ends, and back-locking seams 24 are formed at the two ends of the vertical ribbed grid 22. Several stepped toothed raised ribs 25 are formed at intervals on the vertical ribbed grid 22 between the back-locking seams 24 and the C-shaped latches 23, so that the two ends of the vertical ribbed grid 22 are mechanically self-locked with the two adjacent drainage geogrids 21 through the back-locking structure of C-shaped latches-back-locking seams-stepped toothed raised ribs.

[0066] The C-shaped latch 23 is formed by cutting two vertical notches along the width direction at the other end of the vertical rib strip grid 22; the snap-back seam 24 is a closed slit used to pass through the C-shaped latch 23 and press into the stepped toothed raised rib 25. The number of stepped toothed raised ribs 25 can be adaptively adjusted according to actual connection requirements, and the arrangement interval of the stepped toothed raised ribs 25 is consistent with its height, so that the two vertical rib strip grids 22 can be locked together by the step toothed raised ribs 25.

[0067] Without external fasteners, the C-shaped latch 23 passes through the backlock joint 24, and the stepped toothed rib 25 is pressed in, generating a dual self-locking effect of reverse wedge geometric engagement and surface pressure friction. In addition to mechanical locking, during the road construction phase, during the compaction of excavated soil layers, or under the action of upper loads during the road's service life, the entire geogrid system consisting of the drainage geogrid 21 and the vertical ribbed strip geogrid 22 will be stretched. During this process, the C-shaped latches 23 at both ends of the vertical ribbed strip geogrid 22, which connects the upper and lower horizontally laid drainage geogrid 21, will be further locked, thereby locking the upper and lower layers of drainage geogrid 21. The geogrid 21 and the vertical ribbed grid 22 are interlocked to form an integrated three-dimensional drainage reinforcement network, which can effectively accelerate the drainage consolidation of the compacted slag base course, significantly enhance the drainage efficiency of the compacted slag base course, and improve its early strength and long-term stability. At the same time, through the three-dimensional reinforcement effect formed by the vertical ribbed grid 22, the shear strength, integrity and bearing capacity of the compacted slag base course are significantly enhanced, so that the consolidation water and infiltration water are guided along the drainage geogrid 21 and the vertical ribbed grid 22 into the recycled fine aggregate cushion layer, i.e., the drainage layer 12, located below, and finally discharged to the drainage ditches 5 on both sides of the temporary road structure 4.

[0068] The upper and lower drainage geogrids 21 are locked together by vertical ribbed geogrids 22 to form a spatial truss unit, which can generate an initial tensile strain of 0.5~1.0% during the subsequent backfilling and compaction of slag soil 26 to achieve membrane tension and effectively suppress uneven settlement of the subgrade.

[0069] The supporting layer 31 is a cushion layer made of recycled fine aggregate obtained from the crushing of building demolition waste.

[0070] The permeable brick layer 32 is made of permeable bricks, which are based on engineering waste soil. They are formed by layered material distribution and wet bonding and wet co-pressing. From top to bottom, the permeable bricks consist of an upper hydrophobic infiltration layer, a middle load-bearing skeleton layer, and a bottom capillary fracture layer. The upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer form a pore network that runs from top to bottom. The permeable bricks are provided with a U-shaped high-strength nylon frame around their perimeter. Adjacent permeable bricks can be detachably spliced ​​by spring locks through the U-shaped high-strength nylon frame. The U-shaped high-strength nylon frame is embedded with a polyurethane buffer strip.

[0071] The interconnected porosity and characteristic pore size of the upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer decrease sequentially. Preferably, the interconnected porosity of the upper hydrophobic infiltration layer is 18-22%, and the characteristic pore size is 0.8-1.5 mm; the interconnected porosity of the middle load-bearing skeleton layer is 12-16%, and the characteristic pore size is 0.4-0.8 mm; the interconnected porosity of the bottom capillary fracture layer is 6-10%, and the surface contact angle of the bottom capillary fracture layer is not less than 105°. The top-to-bottom interconnected pore network formed by the upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer enables vertical infiltration of rainwater and inhibits the upward migration and clogging of fine particles.

[0072] The permeable bricks are composed of the following raw materials: engineering waste soil, waste concrete hydrophobic powder, alkali-activated cementitious material, and admixtures; wherein, the total amount of engineering waste soil is 55-70%, which, after screening and dewatering, has a moisture content of no more than 15% and a particle size of no more than 4mm; the total amount of alkali-activated cementitious material is 25-35%, which consists of solid and liquid components in a mass ratio of 3:2, and its solid component is sulfoaluminate cement clinker powder (specific surface area 450m²). 2 The liquid component is composed of water glass with a modulus of 1.8 and S95 grade slag powder in a 1:1 ratio. The liquid component is composed of water glass with a modulus of 1.8 and 10% NaOH solution in a 2:1 ratio, with a modulus of 1.6~2.0. The total amount of admixtures is 0.8~1.5%, including 0.5~0.9% polycarboxylate superplasticizer, 0.2~0.4% shrinkage reducer and 0.1~0.3% stabilizer. The total amount of waste concrete hydrophobic powder is 0.3~0.6%.

[0073] The production reaction principle of permeable bricks is as follows: 1) Early strength and micro-expansion: The sulfoaluminate minerals in the sulfoaluminate cement clinker powder react with the gypsum in the S95 grade slag powder to generate ettringite (AFt) crystal framework, providing early strength and micro-expansion effect to offset part of the drying shrinkage; 2) Later densification and toughening: The S95 grade slag powder is activated in an alkaline environment to generate C~S~H and C~A~S~H cementitious products to fill the interface between aggregate and slurry, improving compressive strength and freeze-thaw stability; 3) Interface optimization: Polycarboxylate superplasticizer forms good dispersion and thin slurry coating, reducing the water-cement ratio, shrinkage reducer reduces the surface tension of pore water, and stabilizer inhibits segregation and bleeding. The polycarboxylate superplasticizer, shrinkage reducer and stabilizer work together to stabilize the interconnected pore structure; 4) Hydrophobic and anti-clogging: The contact angle of the bottom capillary fracture layer is increased to ≥105°, forming a capillary pressure change zone at the bottom of the permeable brick, inhibiting fine particle migration and capillary adsorption, and delaying clogging.

[0074] Please see the appendix Figure 1 A construction method for temporary road structures based on construction waste soil in construction site office and living areas includes the following steps:

[0075] Step 1: Construction of the seepage prevention and drainage layer.

[0076] Specifically, the site for the temporary road structure to be constructed is excavated and leveled. Then, a non-woven geotextile, an HDPE geomembrane, and an upper non-woven geotextile are laid sequentially on the foundation soil 4 to form a seepage barrier layer 11, which is then fixed by back pressure on both sides. Subsequently, a 50-80mm thick layer of recycled fine aggregate made from demolition waste is spread on the seepage barrier layer 11 to form a drainage layer 12.

[0077] Please see the appendix Figure 4 In step 1, the laying width W of the impermeable layer 11 needs to cover the bottom of the temporary road and the entire surface of the drainage ditch 5 on both sides, and make a horizontal fold back at the top of the drainage ditch 5 to form a horizontal fold back section 13. This horizontal fold back section 13 is used for surcharge counter pressure to fix the impermeable layer 11 and prevent it from slipping.

[0078] The laying width W of the impermeable layer 11 is calculated by the following formula:

[0079]

[0080] In the formula: W 防渗 w1 is the laying width of the impermeable layer 11; w1 is the width of the horizontal fold-back section 13 at the top of the reserved water collection ditch 5, for counter-pressure fixing of the impermeable layer 11, 1.0m≤w1≤1.5m; h g Here, h represents the excavation depth and the height of the drainage ditch 5, 0.4m ≤ h. g ≤0.6m; w g The bottom width of the water collection ditch 5 is 0.5m ≤ wg ≤0.8m; W R θ represents the bottom width of the temporary road structure; θ represents the slope of both sides of the temporary road structure. The slope of the drainage ditch 5 is consistent with it, 45°≤θ≤72°, that is, the slope ratio is between 1:1 and 1:0.33.

[0081] Step 2: Compact the soil base layer in layers.

[0082] Specifically, based on the design height of the compacted slag base, the backfill area of ​​slag 26 is divided into 1 to n small areas from bottom to top, with each small area having the same height. The slag backfilling construction of the n small areas is carried out in layers from bottom to top.

[0083] In step 2, the backfilling process for each small area is as follows: laying the drainage geogrid 21 at the bottom of the small area → locking the bottom of the vertical ribbed geogrid 22 → backfilling and compacting the first layer of slag 26 → excavating the anchoring trench 27 at the edge of the first layer of compacted slag → folding back and anchoring the edge of the bottom drainage geogrid 21 → backfilling and compacting the slag 26 within the remaining height → laying the top drainage geogrid 21 → locking the top of the vertical ribbed geogrid 22; wherein, the drainage geogrid 21 laid at the top in the (n-1)th small area also serves as the drainage geogrid 21 at the bottom in the nth small area, thus completing the layered construction of the compacted slag base layer.

[0084] Construction waste 26 can be construction waste from the construction site, realizing the resource reuse of construction waste.

[0085] Please see the appendix Figure 5 Specifically, the backfill height of the first layer of slag 26 in each small area is h1. Then, an anchoring trench 27 with a depth of h' and a width of w' is excavated at a horizontal distance h2 from the edge of this slag layer. The bottom drainage geogrid 21 is then folded back at an angle θ on both sides and buried in the anchoring trench 27. U-shaped nails are used to fix the trench 27 at 50cm intervals along the length of the temporary road structure, at the top and bottom of both sides of the slope and at the center of the bottom of the trench. The anchoring trench 27 is then backfilled and compacted to form a stable mechanical interlock, preventing the drainage geogrid 21 from sliding under tension. The laying width W of each layer of drainage geogrid 21 is calculated using the following formula:

[0086]

[0087] In the formula: h1 is the backfill height of the first layer of slag 26 in the small area, 0.2m≤h1≤0.5m; w is the bottom width of the first layer of backfill slag 26 in the small area; h2 is the horizontal distance from the outer side of the anchoring trench 27 to the edge of the first layer of slag 26, 0.5m≤h2≤1.0m; h' is the depth of the anchoring trench 27, 0.2m≤h'≤0.3m; w' is the width of the anchoring trench 27, 0.5m≤w'≤0.8m; θ is the slope of the temporary road structure on both sides; α is the slope of the anchoring trench 27 on both sides, α≤θ.

[0088] In step 2, the horizontal and vertical spacing of the vertical rib strip grid 22 is d, 0.5m≤d≤1.0m. At the same time, the joints of the upper and lower layers of vertical rib strip grid 22 should be staggered alternately, with a stagger distance of 0.5d.

[0089] In step 2, the backfilling of slag 26 is carried out by layered backfilling and compaction. The backfilling height h1 of the first layer of slag 26 must meet the requirement of 0.2m≤h1≤0.5m. The backfilling height of each layer of slag 26 within the remaining height is 0.15~0.2m. The compaction degree of the backfilled slag 26 is not less than 95%.

[0090] Step 3: Construction of permeable pavement layer.

[0091] The height of the permeable pavement layer is h t 8cm≤h t ≤10cm, a 30-50mm thick layer of recycled fine aggregate obtained from the crushing of building demolition waste is spread on top of the compacted slag base as a support layer 31. Permeable bricks are then dry-laid on the support layer 31 in a herringbone pattern to form a permeable brick layer 32. The brick joint width is 3mm. The edges of two adjacent permeable bricks are constrained by a U-shaped high-strength nylon frame with polyurethane buffer strips embedded on the inside and spring locks.

[0092] Polyurethane buffer strips absorb the impact energy of vehicle tires, preventing the edges and corners of permeable pavers from cracking due to rigid collisions. The elastic deformation of the polyurethane buffer strips allows the permeable pavers to expand and contract by ±1.5mm / m due to temperature changes, eliminating internal stress concentration. A rigid frame formed by U-shaped high-strength nylon resists horizontal slippage caused by vehicle eccentric loading. The spring-locking structure allows for quick unlocking during the dismantling and reuse of temporary road structures, enabling rapid recycling of the permeable pavement layer and meeting the efficiency requirements of modular road turnover.

[0093] The preparation process of the permeable bricks includes the following steps:

[0094] S3-1: After dewatering the engineering waste soil to within 15%, it is screened into 2~4mm coarse aggregate, 0.6~1.2mm fine aggregate, and 0.15~0.6mm fine powder for later use. These are then premixed into three types of soil materials, A, B, and C, respectively, at mass ratios of 4:6 (coarse aggregate: fine aggregate), 3:6:1 (coarse aggregate: fine aggregate: fine powder), and 2:7:1 (coarse aggregate: fine aggregate: fine powder).

[0095] S3-2: Put the three types of soil materials A, B and C into the mixer respectively, spray in the liquid component of the alkali-activated cementitious material and wet mix for 60s, then add the solid component of the alkali-activated cementitious material and mix for 90s to obtain three kinds of mixtures. Among them, waste concrete hydrophobic micro powder needs to be added when mixing the soil material of type C.

[0096] S3-3: In the mold, the material is laid in layers. The bottom layer is laid first to form the bottom capillary fracture layer, the middle layer is laid later to form the middle load-bearing skeleton layer, and the top layer is laid last to form the top hydrophobic infiltration layer. The interval between each layer is no more than 2 minutes. Before laying the middle layer, a 1-2 mm shallow toothed interface is formed on the surface of the bottom capillary fracture layer to enhance the mechanical interlocking between layers.

[0097] In S3-3, the mixture ratio of the upper hydrophobic infiltration layer is: 58-66% of Class A soil, 28-34% of alkali-activated cementitious material, and 0.8-1.2% of admixtures;

[0098] The mix proportions for the intermediate load-bearing skeleton layer are: 60-70% Class B soil, 25-32% alkali-activated cementitious materials, and 0.8-1.2% admixtures;

[0099] The mix proportions of the bottom capillary fracture layer are as follows: Class C soil accounts for 55-65%, alkali-activated cementitious materials account for 30-35%, admixtures account for 0.8-1.2%, and waste concrete hydrophobic micro powder accounts for 0.3-0.6%.

[0100] S3-4: After the material is laid, a three-stage equal pressure and low-amplitude micro-vibration process is used to make bricks. The initial pressure is 5MPa and held for 10s to position the coarse aggregate. The main pressure is 15MPa and held for 20s to force the fine aggregate to fill the gaps between the coarse aggregate. The final pressure is 20MPa and held for 10s to compact the interface transition zone. During the three-stage equal pressure process, there is a micro-vibration frequency of 20~40Hz and a displacement amplitude of ≤0.4mm.

[0101] S3-5: Steam curing with mold for 24 hours at 80℃ and ≥95% humidity, followed by natural curing for 5 days after demolding.

[0102] The permeable bricks prepared through the above steps have a 28-day compressive strength exceeding 38 MPa; a splitting tensile strength exceeding 3.7 MPa; a strength retention rate exceeding 85% after 25 freeze-thaw cycles; and an interlayer bond shear strength exceeding 0.8 MPa.

[0103] The permeability mechanism of permeable bricks is as follows: 1) The discontinuous gradation and micro-vibration rearrangement form interlayer interconnected channels, allowing water to pass through quickly under gravity and micro-pressure difference; 2) The larger pore size of the upper hydrophobic infiltration layer completes the initial screening of mud particles and guides diversion, the continuous channels of the middle bearing skeleton layer reduce local head loss, and the hydrophobic pore group of the bottom capillary fracture layer blocks the upward movement of fine aggregates, maintaining pore connectivity and drainage efficiency; 3) The bottom of the permeable brick is coupled with the support layer 31 and the drainage geogrid 21 below to form a closed water channel of "infiltration - in-surface drainage - collection and external drainage".

[0104] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A temporary road structure based on construction waste soil for construction site office and living areas, characterized in that: The structure includes, from bottom to top, a seepage-proof drainage layer, a compacted slag base layer, and a permeable pavement layer. The seepage-proof drainage layer is laid on the foundation soil (4). The seepage-proof drainage layer includes, from top to bottom, a seepage-proof layer (11) and a drainage layer (12). The two sides of the drainage layer (12) are connected to the water collection ditch (5) of the construction site. At least two horizontally laid drainage geogrids (21) are installed in the compacted slag base layer. Slag (26) is backfilled between two adjacent drainage geogrids (21), and the two adjacent drainage geogrids (21) are connected by vertical ribbed grids (22) to form an integrated three-dimensional drainage reinforcement network. The permeable pavement layer includes, from bottom to top, a support layer (31) and a permeable brick layer (32). The impermeable layer (11) is made of HDPE geomembrane with non-woven geotextile protective layers on both sides; the laying width of the HDPE geomembrane covers the construction area of ​​the temporary road structure at the construction site and the drainage ditches (5) on both sides. The drainage layer (12) is composed of recycled fine aggregate obtained from the crushing of building demolition waste, serving as a water collection layer for the compacted slag base and connected to the water collection ditches (5) on both sides; The surface of the drainage geogrid (21) and the vertical ribbed bar geogrid (22) is provided with micropores, and several drainage channels are arranged in the transverse and longitudinal directions in the surface. Several drainage channels are slightly raised along the length direction to form microchannels for seepage flow. The vertical ribbed grid (22) has C-shaped latches (23) formed at both ends. The vertical ribbed grid (22) has back-locking seams (24) formed at both ends. The vertical ribbed grid (22) between the back-locking seams (24) and the C-shaped latches (23) has several stepped tooth protruding ribs (25) formed at intervals. This allows the two ends of the vertical ribbed grid (22) to be mechanically self-locked by the C-shaped latches-back-locking seams-stepped tooth protruding ribs structure and the two adjacent drainage geogrids (21). The supporting layer (31) is a cushion layer made of recycled fine aggregate obtained from the crushing of building demolition waste; The permeable brick layer (32) is made of permeable bricks; the permeable bricks are based on engineering slag soil, and are formed by layered material distribution and wet joint pressing. From top to bottom, the permeable bricks include an upper hydrophobic infiltration layer, a middle load-bearing skeleton layer and a bottom capillary fracture layer. The upper hydrophobic infiltration layer, the middle load-bearing skeleton layer and the bottom capillary fracture layer form a pore network that runs from top to bottom. The permeable bricks are provided with a U-shaped high-strength nylon frame in the circumference. Two adjacent permeable bricks are detachably spliced ​​by spring locks through the U-shaped high-strength nylon frame. The U-shaped high-strength nylon frame is inlaid with a polyurethane buffer strip.

2. The temporary road structure based on construction waste soil for construction site office and living areas as described in claim 1, characterized in that: The interconnected porosity of the upper hydrophobic infiltration layer, the middle load-bearing skeleton layer, and the bottom capillary fracture layer decreases sequentially, as does the characteristic pore size; the surface contact angle of the bottom capillary fracture layer is not less than 105°.

3. The temporary road structure based on construction waste soil for construction site office and living areas as described in claim 1, characterized in that: The permeable bricks are composed of the following raw materials: engineering waste soil, waste concrete hydrophobic powder, alkali-activated cementitious material, and admixtures; wherein, the total amount of engineering waste soil is 55-70%, which is screened and dewatered, with a moisture content not exceeding 15% and a particle size not exceeding 4mm; the total amount of alkali-activated cementitious material is 25-35%, composed of solid and liquid components in a mass ratio of 3:2, wherein the solid component is a 1:1 mixture of sulfoaluminate cement clinker powder and S95 grade slag powder, and the liquid component is a 2:1 mixture of water glass with a modulus of 1.8 and a 10% concentration of NaOH solution, with a modulus of 1.6-2.0; the total amount of admixtures is 0.8-1.5%, including 0.5-0.9% polycarboxylate superplasticizer, 0.2-0.4% shrinkage reducer, and 0.1-0.3% stabilizer; and the total amount of waste concrete hydrophobic powder is 0.3-0.6%.

4. A construction method for a temporary road structure based on construction waste soil in the construction site office and living area as described in any one of claims 1-3, characterized in that: Includes the following steps: Step 1: Construction of the seepage prevention and drainage layer; The site for the temporary road structure to be constructed was excavated and leveled. Then, a non-woven geotextile, an HDPE geomembrane, and an upper non-woven geotextile were laid on the foundation soil (4) to form a seepage barrier layer (11), and a counter-pressure was applied on both sides. Then, recycled fine aggregate made from demolition waste was spread on the seepage barrier layer (11) to form a drainage layer (12). Step 2: Compact the soil base layer in layers; According to the design height of the compacted slag base, the backfill area of ​​slag (26) is divided into 1 to n small areas from bottom to top. Each small area has the same height. The slag backfilling construction of n small areas is carried out in sequence from bottom to top. Step 3: Construction of permeable pavement layer; On top of the compacted slag base, recycled fine aggregate obtained from the crushing of building demolition waste is spread as a support layer (31). Permeable bricks are dry-laid on the support layer (31) in a herringbone pattern to form a permeable brick layer (32). The edges of two adjacent permeable bricks are constrained by spring locks through a U-shaped high-strength nylon frame with polyurethane buffer strips embedded on the inner side.

5. The construction method according to claim 4, characterized in that: In step 1, the laying width W of the seepage-proof layer (11) covers the bottom of the temporary road and the entire surface of the drainage ditch (5) on both sides, and is horizontally folded back at the top of the drainage ditch (5) to form a horizontal fold section (13). The laying width W of the impermeable layer (11) is calculated by the following formula: ； In the formula: W 防渗 w1 is the width of the impermeable layer (11); w1 is the width of the horizontal fold-back section (13) at the top of the reserved water collection ditch (5), 1.0m≤w1≤1.5m; h g The depth of the site excavation is also the height of the drainage ditch (5), 0.4m≤h g ≤0.6m; w g The bottom width of the water collection ditch (5) is 0.5m ≤ w g ≤0.8m; W R θ is the bottom width of the temporary road structure; θ is the slope of both sides of the temporary road structure. The slope of the drainage ditch (5) is the same as that of the temporary road structure. 45°≤θ≤72°, that is, the slope ratio is between 1:1 and 1:0.

33.

6. The construction method according to claim 4, characterized in that: In step 2, the construction process of backfilling the slag in each small area is as follows: laying the drainage geogrid (21) at the bottom of the small area → locking the bottom of the vertical rib strip geogrid (22) → backfilling and compacting the first layer of slag (26) → excavating the anchoring trench (27) at the edge of the first layer of compacted slag → folding back and anchoring the bottom drainage geogrid (21) → backfilling and compacting the slag (26) within the remaining height → laying the top drainage geogrid (21) → locking the top of the vertical rib strip geogrid (22); wherein, the drainage geogrid (21) laid at the top in the n-1th small area also serves as the drainage geogrid (21) at the bottom in the nth small area, thus completing the layered construction of the compacted slag base layer; Specifically, the backfill height of the first layer of slag (26) in each small area is h1. Then, an anchoring trench (27) with a depth of h' and a width of w' is excavated at a horizontal distance h2 from the edge of the slag layer. The bottom drainage geogrid (21) is then folded back at an angle θ on both sides and buried in the anchoring trench (27). Multiple U-shaped nails are used to fix the anchoring trench (27) at intervals along the length of the temporary road structure at the top and bottom of the slopes on both sides of the anchoring trench (27) and at the center of the bottom of the anchoring trench (27). The anchoring trench (27) is then backfilled and compacted to form a stable mechanical interlock. The laying width W of each layer of drainage geogrid (21) is calculated by the following formula: ； In the formula: h1 is the backfill height of the first layer of slag (26) in the small area, 0.2m≤h1≤0.5m; w is the bottom width of the first layer of backfill slag (26) in the small area; h2 is the horizontal distance from the outside of the anchoring trench (27) to the edge of the first layer of slag (26), 0.5m≤h2≤1.0m; h' is the depth of the anchoring trench (27), 0.2m≤h'≤0.3m; w' is the width of the anchoring trench (27), 0.5m≤w'≤0.8m; θ is the slope of the temporary road structure on both sides; α is the slope of the anchoring trench (27) on both sides, α≤θ; In step 2, the horizontal and vertical spacing of the vertical rib strip grid (22) is d, 0.5m≤d≤1.0m. At the same time, the joints of the vertical rib strip grid (22) of the upper and lower layers should be staggered alternately, with a stagger distance of 0.5d. In step 2, the backfilling of the slag (26) is carried out by layered backfilling and compaction. The backfilling height h1 of the first layer of slag (26) must meet the requirement of 0.2m≤h1≤0.5m. The backfilling height of each layer of slag (26) within the remaining height is 0.15~0.2m. The compaction degree of the backfilled slag (26) is not less than 95%.

7. The construction method according to claim 4, characterized in that: The preparation process of the permeable bricks includes the following steps: S3-1: After dewatering the construction waste soil to within 15%, it is sieved into 2~4mm coarse aggregate, 0.6~1.2mm fine aggregate, and 0.15~0.6mm fine powder for later use. These are then premixed into three types of soil materials, A, B, and C, according to the following mass ratios: coarse aggregate: fine aggregate = 4:6, coarse aggregate: fine aggregate: fine powder = 3:6:1, and coarse aggregate: fine aggregate: fine powder = 2:7:

1. S3-2: Put the three types of soil materials A, B and C into the mixer respectively, spray in the liquid component of the alkali-activated cementitious material and wet mix for 60 seconds, then add the solid component of the alkali-activated cementitious material and mix for 90 seconds to obtain three kinds of mixtures. Among them, waste concrete hydrophobic micro powder needs to be added when mixing the soil material of type C. S3-3: In the mold, the material is laid in layers. The bottom layer is laid first to form the bottom capillary fracture layer, the middle layer is laid later to form the middle load-bearing skeleton layer, and the top layer is laid last to form the top hydrophobic infiltration layer. The interval between each layer is no more than 2 minutes. Before laying the middle layer, a 1-2 mm shallow toothed interface is formed on the surface of the bottom capillary fracture layer. The mix proportions of the upper hydrophobic infiltration layer are as follows: Class A soil accounts for 58-66%, alkali-activated cementitious materials account for 28-34%, and admixtures account for 0.8-1.2%. The mix proportions for the intermediate load-bearing skeleton layer are: 60-70% Class B soil, 25-32% alkali-activated cementitious materials, and 0.8-1.2% admixtures; The mix proportions for the bottom capillary fracture layer are: 55-65% Class C soil, 30-35% alkali-activated cementitious materials, 0.8-1.2% admixtures, and 0.3-0.6% waste concrete hydrophobic powder; S3-4: After the material is laid, a three-stage equal pressure and low-amplitude micro-vibration process is used to make bricks. The initial pressure is 5MPa and held for 10s to position the coarse aggregate. The main pressure is 15MPa and held for 20s to force the fine aggregate to fill the gaps between the coarse aggregate. The final pressure is 20MPa and held for 10s to compact the interface transition zone. During the three-stage equal pressure process, the micro-vibration frequency is 20~40Hz and the displacement amplitude is ≤0.4mm. S3-5: Steam curing with mold for 24 hours at 80℃ and ≥95% humidity, followed by natural curing for 5 days after demolding.

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