阅读说明：本技术 一种机场水泥混凝土道面维修改造的施工方法 (Construction method for maintaining and transforming airport cement concrete pavement ) 是由 杨印旺 郭伟林 马荣 关秀丽 吕英 谢俊平 仝宗义 贺亚琴 张洁玙 袁丽 于 2021-06-07 设计创作，主要内容包括：本发明属于机场道面维修改造保养的技术领域,具体是一种机场水泥混凝土道面维修改造的施工方法。包括以下步骤：S1～旧道面的复查检测；S2～原材料的选择与检测；S3～配合比调试；S4～铺设第一次油毛毡,对旧道面分仓缝纵向、横向贴缝隔离；S5～独立仓模板的安装；S6～混凝土摊铺前在独立仓内侧沿模板铺设第二次油毛毡；S7～加铺混凝土拌合、运输、摊铺及振捣；S8～混凝土振捣完成后插入拉杆筋；S9～新道面的整平、提浆、抹面及拉毛；S10～道面养护；S11～对于盖被混凝土与旧道面混凝土对缝切割；S12～拆模；S13～切缝完成、混凝土养护期结束及道面干燥后进行扩缝；S14～调直拉杆筋；S15～填仓内壁铺设第三次油毛毡。(The invention belongs to the technical field of airport pavement maintenance, and particularly relates to a construction method for maintaining and reconstructing an airport cement concrete pavement. The method comprises the following steps: s1, rechecking and detecting the old pavement; s2 selecting and detecting raw materials; s3, debugging the mixture ratio; s4, paving a first felt, and longitudinally and transversely jointing and isolating the old pavement parting seams; s5, mounting of the independent bin template; s6 paving a second felt along the template on the inner side of the independent bin before paving the concrete; s7, adding and paving concrete, mixing, transporting, paving and vibrating; s8, inserting a pull rod rib after the concrete is vibrated; s9, leveling, slurry extracting, plastering and napping a new road surface; s10-pavement maintenance; s11, butt-joint cutting of the comforter concrete and the old pavement concrete; s12-form removal; s13, joint cutting is completed, the concrete curing period is finished, and joint expansion is carried out after the road surface is dried; s14, adjusting tie rod ribs; s15 laying a third felt on the inner wall of the filling bin.)

1. A construction method for maintaining and reconstructing an airport cement concrete pavement is characterized by comprising the following steps: the method comprises the following steps:

s1, rechecking and detecting the old pavement;

s2 selecting and detecting raw materials;

s3, debugging the mixture ratio;

s4, paving a first felt, and longitudinally and transversely jointing and isolating the old pavement parting seams;

s5, mounting of the independent bin template;

s6, before concrete is paved, paving a second felt along the template on the inner side of the independent bin, and vertically paving the felt;

s7, adding and paving concrete, mixing, transporting, paving and vibrating;

s8, inserting a pull rod rib after the concrete is vibrated;

s9, leveling, slurry extracting, plastering and napping a new road surface;

s10-pavement maintenance;

s11, butt-joint cutting of the comforter concrete and the old pavement concrete;

s12-form removal;

s13, joint cutting is completed, the concrete curing period is finished, and joint expansion is carried out after the road surface is dried;

s14, adjusting tie rod ribs;

s15 paving a third felt on the inner wall of the filling bin;

s16 is repeated S7 → S9 → S10 → S11 → S13 to carry out the construction of filling concrete.

2. The construction method for repairing and reconstructing the airport cement concrete pavement according to claim 1, wherein: the step S5 includes a method of,

s5.1-preparation of collapsed cake: smearing mortar collapsed cakes every 10m on the bin dividing line and marking out a plane position, wherein the elevation of the mortar collapsed cakes is 5mm lower than the lower edge of the template;

s5.2, adopting a formwork supporting method of one-by-one alternate construction;

s5.3, adjusting the plane position by adjusting the mould, wherein the allowable deviation of the plane position is +/-3 mm, checking the width, adjusting the elevation again, and adjusting the allowable error to be +/-2 mm, wherein the virtual width is-2 multiplied by 2mm of the concrete slab width;

and S5.4, after the template is checked to be correct, firmly pasting the joints of the template and the holes of the pull rods reserved in the template by using sealing glue to prevent slurry leakage, filling cement mortar at the joints of the bottom of the template and the old pavement, plugging by using felt, and brushing a release agent on the template before pouring concrete.

3. The construction method for repairing and reconstructing the airport cement concrete pavement according to claim 1, wherein: the step S9 includes a method of,

s9.1-leveling road surface: after the vibrating is finished, the small flat plate is used for dragging and vibrating for 1-2 times to carry out compaction, slurry lifting and preliminary leveling, the vibrated concrete surface is slowly moved on the concrete surface by using a vibrating row, the leveling and slurry kneading are carried out repeatedly until the surface is completely leveled, the first round uses a level gauge to measure the elevation again before and after the leveling, and the second round and the third round use a wire drawing method to measure the elevation of the template again;

s9.2-slurry extraction on road surface: after leveling, rolling and kneading the slurry back and forth by using a steel roller, simultaneously checking the position and the elevation of a template, testing the flatness of the surface by using a ruler with the length not less than 3.0m when the mixture is still in a plastic state, grinding the higher part, completing the lower part, scraping the redundant mortar, finally leveling by using putty, and removing redundant water and laitance on the surface;

s9.3-road surface plastering: rubbing the sand with wood in the first two times, pressing the sand into the board surface, rolling out surface bleeding, extruding out air bubbles, and leveling with wood so that the slurry is more uniformly distributed on the surface of the concrete and the thickness of the slurry reaches 3-5 mm; finally, pressing sand and collecting slurry by using steel plastering for two times, eliminating sand holes, compacting the board surface and eliminating various residual uneven marks on the board surface;

s9.4-napping the pavement.

4. The construction method for repairing and reconstructing the airport cement concrete pavement according to claim 1, wherein: the step S11 includes the following steps that when the joint is cut, the position of the joint is accurately measured, the cover is cut by the concrete and the concrete of the old pavement in a butt joint mode, the depth of the joint is 1/3-1/5 h, the thickness of the joint is h, the joint is marked by an ink fountain pop-up mark to serve as joint cutting guide, then a joint cutter is used for performing pavement joint cutting, slurry is washed clean after the joint cutting, and the joint groove is filled with fillers.

5. The construction method for repairing and reconstructing the airport cement concrete pavement according to claim 1, wherein: the step S12 includes the following steps, and the earliest stripping time after the concrete surface layer is formed should meet the following specifications:

earliest form removal time after concrete slab forming

Temperature in situ (. degree. C.) Earliest time (h) for concrete filling and pouring 5 to 10 (10 excluded) 72 10 to 15 (15 is not included) 54 15 to 20 (20 is not included) 36 20 to 25 (25 is not included) 24 ≥25 18

。

6. The construction method for repairing and reconstructing the airport cement concrete pavement according to claim 1, wherein: and step S13, the joint is expanded after the joint cutting is finished, the concrete curing period is finished and the road surface is dried, the temperature is higher than 5 ℃ during the joint expansion, fillers, sand, stones, soil, laitance, curing compounds and other sundries in the joint are cleaned before the joint expansion, and the joint is blown clean by a compressed air machine after the cleaning is finished.

Technical Field

The invention belongs to the technical field of airport pavement maintenance, and particularly relates to a construction method for maintaining and reconstructing an airport cement concrete pavement.

Background

With the development of the air transportation industry, newly built airports in the eight and ninety years gradually enter a wide range of repair and maintenance stages. A large amount of cement concrete pavements have defects such as corner damage, surface net shape, strip or annular cracks, plate body fracture and the like, and are in urgent need of maintenance. The pavement is paved and maintained through the covering, and the technology is economical, short in construction period and relatively simple in process. At present, the old cement concrete pavement is paved with asphalt concrete (commonly called 'white plus black') commonly used in airport runway engineering, the technology has the advantages of strong adaptability to deformation or uneven settlement of a base layer, high pavement repairing speed and early traffic opening without navigation construction, but the technology has the problems of poor flatness maintenance, poor stability, poor durability and low strength. The cement concrete pavement has the advantages of high strength, good stability, relatively long service life, simple daily maintenance and the like, but the construction technology of paving cement concrete (commonly called 'white plus white') on the old cement pavement is still in the starting stage and the process is not mature.

Disclosure of Invention

The invention provides a construction method for maintaining and reconstructing an airport cement concrete pavement, aiming at solving the problem that the maintenance and reconstruction of the old cement concrete airport pavement with a large maintenance area are needed for various quality defects generated by the aging of the old pavement.

The invention adopts the following technical scheme: a construction method for maintaining and reconstructing an airport cement concrete pavement comprises the following steps.

S1, rechecking and detecting the old pavement; the method comprises the steps of detecting and evaluating the void of an old pavement concrete slab, the uniform condition of a structural layer of the old pavement concrete slab and the pavement bearing capacity by adopting a ground penetrating radar and a deflectometer to determine the damage condition of the pavement, and taking different treatment measures according to different conditions to ensure that the old pavement has enough bearing capacity and meet construction requirements.

Cleaning rotten wood boards and weeds in bins of the old airport pavement, and sealing seams by using asphalt mastic; reinforcing the pits formed by the falling stones and the local damage generated by the aging of the pavement by using double-component epoxy repair mortar (commonly called leakage repairing king); for an old pavement with deeper and wider damaged corners, cutting off the damaged part by using a cutting machine, and then pouring C30 concrete; removing more than 5cm of old pavement with shallow and narrow corner damage, and filling with concrete mixture mixed with fine stone; the marking lines on the old pavement are required to be planed and washed clean, so that the marking lines can be prevented from influencing the adhesion between the new pavement and the old pavement.

The back side of the comforter reaches the structural strength close to the old side, and the average comforter thickness is determined to be 26cm through analysis and demonstration. When the thickness of the comforter is less than 22cm but more than or equal to 18cm, a single-layer net reinforcing steel bar is additionally arranged for reinforcement, and when the thickness of the comforter is less than 18cm, the original pavement is broken and newly built, and the comforter is connected with a slope by breaking boards on the surrounding pavement. And determining the thickness of the concrete covered by the cover through elevation measurement, and taking a targeted treatment measure.

S2 selecting and detecting raw materials; according to the construction technical requirements of pavement concrete (the pavement flexural strength is more than or equal to 5.0MPa, the compressive strength is more than or equal to C30), raw materials are selected through experiments, and the raw materials and the material dosage proportion which meet the requirements of various technical indexes and are economical and reasonable such as cement, sand, stone, additives and the like are selected.

S3, debugging the mixture ratio;

s4, paving a first felt, and longitudinally and transversely jointing and isolating the old pavement parting seams;

s5, installing independent bin templates, wherein the independent bin templates are respectively installed on the first felt on two sides of each bin dividing seam, and a connecting pull rod is arranged between the independent bin templates on the two sides;

s6, before concrete is paved, paving a second felt along the template on the inner side of the independent bin, and vertically paving the felt;

s7, adding and paving concrete, mixing, transporting, paving and vibrating;

s8, inserting a pull rod rib after the concrete is vibrated;

s9, leveling, slurry extracting, plastering and napping a new road surface;

s10-pavement maintenance;

s11, butt-joint cutting of the comforter concrete and the old pavement concrete;

s12-form removal;

s13, joint cutting is completed, the concrete curing period is finished, and joint expansion is carried out after the road surface is dried;

s14, adjusting tie rod ribs;

s15 paving a third felt on the inner wall of the filling bin;

s16 is repeated S7 → S9 → S10 → S11 → S13 to carry out the construction of filling concrete.

Step S5 includes a method of,

s5.1-preparation of collapsed cake: smearing mortar collapsed cakes every 10m on the bin dividing line and marking out a plane position, wherein the elevation of the mortar collapsed cakes is 5mm lower than the lower edge of the template;

s5.2, adopting a mode supporting method (a skip method) of one-to-one spacing; the method fully utilizes the 'anti-release' characteristic principle that the performance of the concrete is not stable in a period of 5 to 10 days and the internal stress is easily released before the concrete is not completely solidified, divides a large-area concrete plane into a plurality of areas, and constructs according to the principle of 'block planning, spacer block construction, sectional pouring and integral molding'.

S5.3, adjusting the plane position by adjusting the mould, wherein the allowable deviation of the plane position is +/-3 mm, checking the width, adjusting the elevation again, and adjusting the allowable error to be +/-2 mm, wherein the virtual width is-2 multiplied by 2mm of the concrete slab width;

and S5.4, after the template is checked to be correct, firmly pasting the joints of the template and the holes of the pull rods reserved in the template by using sealing glue to prevent slurry leakage, filling cement mortar at the joints of the bottom of the template and the old pavement, plugging by using felt, and brushing a release agent on the template before pouring concrete.

Step S9 includes a method of,

s9.1-leveling road surface: after the vibrating is finished, the small flat plate is used for dragging and vibrating for 1-2 times to carry out compaction, slurry lifting and preliminary leveling, the vibrated concrete surface is slowly moved on the concrete surface by using a vibrating row, the leveling and slurry kneading are carried out repeatedly until the surface is completely leveled, the first round uses a level gauge to measure the elevation again before and after the leveling, and the second round and the third round use a wire drawing method to measure the elevation of the template again;

s9.2-slurry extraction on road surface: after leveling, rolling and kneading the slurry back and forth by using a steel roller, simultaneously checking the position and the elevation of a template, testing the flatness of the surface by using a ruler with the length not less than 3.0m when the mixture is still in a plastic state, grinding the higher part, completing the lower part, scraping the redundant mortar, finally leveling by using putty, and removing redundant water and laitance on the surface;

s9.3-road surface plastering: rubbing the sand with wood in the first two times, pressing the sand into the board surface, rolling out surface bleeding, extruding out air bubbles, and leveling with wood so that the slurry is more uniformly distributed on the surface of the concrete and the thickness of the slurry reaches 3-5 mm; finally, pressing sand and collecting slurry by using steel plastering for two times, eliminating sand holes, compacting the board surface and eliminating various residual uneven marks on the board surface;

s9.4-napping the pavement.

And step S11 comprises the following steps that when the joint is cut, the position of the joint is accurately measured, the cover is cut by the concrete and the concrete of the old pavement in a butt joint mode, the depth of the joint is 1/3-1/5 h, h is the plate thickness, an ink fountain pop-up mark is used as joint cutting guide, then a joint cutter is used for pavement joint cutting, slurry is washed clean after the joint cutting, and the joint groove is filled with fillers.

Step S12 includes the following method, where the earliest demold time after the concrete facing is formed should meet the specifications of the following table:

temperature in situ (. degree. C.)	Concrete warehouse filling and pouringEarliest time (h)
		5 to 10 (10 excluded)	72
10 to 15 (15 is not included)	54
		15 to 20 (20 is not included)	36
20 to 25 (25 is not included)	24
		≥25	18

Step S13 includes the steps of joint-cutting, curing the concrete, expanding the joint after the road surface is dried, the temperature is higher than 5 ℃, cleaning the stuffing, sand, stone, mud, floating slurry, curing compound and other sundries in the joint before expanding the joint, and blowing the joint clean by a compressed air machine after cleaning.

Compared with the prior art, the invention has the following beneficial effects:

1. the combined repair, reconstruction and maintenance construction process of the 'white plus white' part reduces raw materials, reduces energy consumption, reduces environmental pollution and is green and environment-friendly.

2. The process reduces the damage of the old pavement to the reflection cracks of the newly-added pavement, improves the bonding quality of the new and old pavements, and improves the quality and the service life of the new pavement.

3. In the maintenance and transformation of the road surface without navigation construction, the method is environment-friendly and quick, and reduces the construction and later maintenance cost. The method provides reasonable reference value for non-navigation maintenance reconstruction construction of similar airports in future, and has strong economic benefit and social benefit.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a schematic plan view of a combined "white + white" portion for repair, reconstruction and maintenance;

FIG. 3 is a sectional view taken in the direction I-I of FIG. 2 (1);

FIG. 4 is a sectional view taken in the direction I-I of FIG. 2 (2);

FIG. 5 is a schematic view of an individual bin template;

in the figure, 1-felt, 2-pull rod, 3-second felt, 4-first felt, 5-old concrete pavement, 6-template and 7-third felt.

Detailed Description

A construction method for maintaining and reconstructing an airport cement concrete pavement comprises the following steps.

And S1, rechecking, detecting, cleaning and maintaining the old pavement.

The elevation and the damage condition of the old pavement are mainly known, the defects of the old cement pavement are counted according to the bin numbers of the areas through manual investigation, and the ground penetrating radar and the deflectometer are adopted to detect and evaluate the void of the concrete slab, the uniform condition of the structural layer of the concrete slab and the bearing capacity of the pavement.

Cleaning rotten wood boards and weeds in bins of the old airport pavement, and sealing seams by using asphalt mastic; reinforcing the pits formed by the falling stones and the local damage generated by the aging of the pavement by using double-component epoxy repair mortar (commonly called leakage repairing king); for an old pavement with deeper and wider damaged corners, cutting off the damaged part by using a cutting machine, and then pouring C30 concrete; removing more than 5cm of old pavement with shallow and narrow corner damage, and filling with concrete mixture mixed with fine stone; the marking lines on the old pavement are required to be planed and washed clean, so that the marking lines can be prevented from influencing the adhesion between the new pavement and the old pavement.

The back side of the comforter reaches the structural strength close to the old side, and the average comforter thickness is determined to be 26cm through analysis and demonstration. When the thickness of the comforter is less than 22cm but more than or equal to 18cm, a single-layer net reinforcing steel bar is additionally arranged for reinforcement, and when the thickness of the comforter is less than 18cm, the original pavement is broken and newly built, and the comforter is connected with a slope by breaking boards on the surrounding pavement. And determining the thickness of the concrete covered by the cover through elevation measurement, and taking a targeted treatment measure.

And S2, selecting and detecting raw materials.

The cement concrete for the white quilt has strict requirements on raw materials. Selecting raw materials of cement, sand, stone and an additive through tests, and selecting raw materials and material dosage proportion which meet the construction technical requirements of pavement concrete (the pavement flexural strength is more than or equal to 5.0MPa, and the compressive strength is more than or equal to C30) and are economical and reasonable; the ideal gradation of the sand aggregate is selected preferably, the concrete mixture is required to have certain fluidity, so that the concrete mixture has good interlocking capability, the materials are saved to the maximum extent, the quality of the concrete is ensured, and the breaking strength of the concrete is improved.

1) The cement is ordinary portland cement, the strength grade is 42.5 grade; tests show that all indexes of the product meet the requirements of MH 5006-2015 and GB 175-2007;

2) crushing stone: the 4.75-31.5 mm continuous graded macadam (the doping amount of the 4.75-19 mm is 15%, and the doping amount of the 16-31.5 mm is 85%); tests show that all indexes of the product meet the requirements of MH 5006-2015 and JGJ 52-2006 specifications;

3) sand: river sand or river sand with fineness modulus of 2.83; tests show that all indexes of the product meet the requirements of MH 5006-2015 and JGJ 52-2006 specifications;

and S3, adjusting the mixing ratio.

And performing workability and trial strength tests by adopting the reference mixing ratio and other mixing ratios according to the current standard specification, and obtaining the optimal mixing ratio according to the workability and the trial strength test results of 7 days and 28 days. According to the test result, the optimal mix proportion of the concrete is obtained, and the mix proportion of 5.75MPa of the surface layer concrete of the pilot strength apron pavement can be met:

s4, laying a first felt (50 cm seam laying).

In order to prevent the occurrence of reflection cracks, the asphalt felt is used as an isolation material to isolate longitudinal and transverse joint sticking of the cabin-dividing seam of the old pavement of the airport, and the total thickness of the asphalt felt is not more than 6 mm. The width of the felt is 50cm, the two sides of the seam are respectively attached with 25cm, the felt has certain tear strength, puncture strength and impermeability, and is not easy to wrinkle, fold or puncture under the action of a transport vehicle. The concrete is paved before spreading, so that too many concrete layers are not paved, and rolling of a transport vehicle is prevented.

And S5, installing the independent bin template and checking the bin.

The template is a standard steel template with the thickness of 6mm and the length of 5 m; the bend template is a wood template, and the thickness of the wood template is 2-3 cm.

S5.1, template installation:

1) making collapsed cakes: and smearing mortar collapsed cakes every 10m on the bin dividing line and marking out the plane position, wherein the elevation of the mortar collapsed cakes is 5mm lower than the lower edge of the template.

2) A mold supporting method (skip method) of one-by-one is adopted. The method fully utilizes the 'anti-release' characteristic principle that the performance of the concrete is not stable in a period of 5 to 10 days and the internal stress is easily released before the concrete is not completely solidified, divides a large-area concrete plane into a plurality of areas, and constructs according to the principle of 'block planning, spacer block construction, sectional pouring and integral molding'.

3) Adjusting the plane position of the mould, wherein the allowable deviation of the plane position is +/-3 mm, and the virtual width is-2 multiplied by 2 mm. Then the elevation is adjusted, and the allowable error is +/-2 mm.

4) After the template is checked to be correct, the joints of the template and the holes of the pull rods reserved in the template are firmly pasted by sealing glue to prevent slurry leakage, the joints of the bottom of the template and the old road surface are filled with cement mortar, then are plugged by using an oil felt, and a release agent is brushed on the template before concrete pouring.

S5.2, checking the bin:

when the construction of the independent bin is carried out, the elevation and the thickness of the template, the oil brushing (mold release agent) on the inner wall of the template and the installation firmness are checked; when the warehouse filling construction is carried out, asphalt is coated on the side face of a concrete plate, blocking mortar at the bottom of the plate is removed, water is sprayed to wet a contact surface in the warehouse filling, and the warehouse filling concrete is poured in time strictly according to the standard.

S6, laying a second felt (50 cm vertical laying).

And laying a second time of felt along the template on the inner side of the independent bin, wherein the felt is vertically laid, 25cm is on the old road surface, and 25cm is tightly attached to the inner wall of the template. Before concrete is paved, a second felt is paved, and the concrete mixture is fixed and pressed every 2m of length and the joint. The overlapping length of the felt is not less than 10cm, the felt is paved according to the paving progress of concrete when being paved, and the felt is not too long, so that rolling and pollution of a transport vehicle are prevented.

And S7, adding and paving concrete, mixing, transporting, paving and vibrating.

1) The concrete is intensively mixed in a mixing plant, the mixture is calculated according to the weight ratio, and the allowable error does not exceed the standard required value.

2) The concrete mixture is transported to a paving section by a dump truck in the shortest time, and the time from discharging to a paving site is ensured to be not more than 30 min.

3) The transport vehicle is covered by tarpaulin if necessary according to the temperature condition.

4) When the vehicle enters a paving section and is unloaded, the vehicle is commanded to avoid colliding the template, the dowel bar bracket and the corner of the poured pavement concrete and unloading the mixture onto the dowel bar bracket and the template.

5) The unloading height of the vehicle is ensured not to exceed 1.5 m.

6) And (3) paving the board once according to the full thickness of the board by adopting a small excavator, and manually leveling the board.

7) The settlement degree of the reserved jolt is strictly controlled according to the loose paving coefficient 1.10-1.15 given by the construction of the test section.

8) Considering the transverse slope of the plate, the virtual share value at the high side is about 3cm higher than that at the low side.

9) The travel speed limit of the row-type vibrator is 0.8 m/min, the walking is stopped once by 30cm, the vibrating time is 30-50 seconds, and the row-type vibrator walks again after the concrete is fully exhausted and has no bubbles, sinks and floating slurry. In the vibrating process, manual leveling is needed, the height is increased and decreased, and the vibrating process is carried out again, so that the surface which is not only provided with the milk but also approximately flat is presented after the vibrating process is finished.

10) The self-propelled high-frequency row type vibrator and the inserted vibrator are adopted in construction for vibration, so that the vibrating effect is more ideal, and two manually vibrated vibrators follow the vibrator for vibration. The edge and end of the concrete slab are vibrated secondarily by a 1.9kw inserted vibrator.

And S8, inserting a pull rod rib.

1) The pull rod is processed according to the design, holes are formed in the template according to the design when the template is processed, and a specially-assigned person is arranged to place the pull rod when concrete is poured.

2) After the concrete is vibrated, a special person inserts the pull rod rib, the horizontal angle of the inserted pull rod rib slightly inclines upwards for a certain degree, the steel formwork is convenient to remove, and the pull rod rib is immediately adjusted after the steel formwork is removed.

S9, leveling, pulping, plastering and napping the new road surface.

S9.1, leveling the road surface:

after the row-type vibrator finishes vibrating, the row-type vibrator is dragged to vibrate for 1-2 times by using a 1.1kw small flat plate to perform compaction, slurry lifting and preliminary leveling, and a full-width vibrating row rammer which is made of single wood and is embedded with a steel plate on the bottom surface slowly moves on the concrete surface to and fro leveling and slurry kneading until the surface is completely leveled.

The template is likely to be misplaced and sunk due to the large mechanical vibration force, and the rechecking correction is required. Before and after leveling, the elevation of the template is remeasured by a level gauge for the first round, and the elevation of the template is remeasured by a pull wire method for the second round and the third round.

S9.2, slurry extraction on road surface:

and after leveling, rolling and kneading the mortar back and forth by adopting a specially-made steel roller, checking the position and the elevation of the template, testing the flatness of the surface by using a ruler with the length not less than 3.0m when the mixture is still in a plastic state, grinding the higher part, completing the lower part, and scraping the redundant mortar. Finally, leveling with specially-made aluminum alloy, and removing the redundant water and floating slurry on the surface.

During construction, after the tamping leveling and roller pulp kneading procedures are finished in each section of the casting storehouse surface, the tamping and the roller are prevented from stopping on the road surface joint as much as possible.

S9.3, paving the pavement:

the surface is made by 3 times of wood plastering and 2 times of steel plastering, and is matched with the construction process of an aluminum alloy leveling ruler. And rubbing the concrete by using wood, pressing sand into the surface of the concrete, rolling out surface bleeding, extruding air bubbles, and leveling by using the wood, so that the slurry is more uniformly distributed on the surface of the concrete, and the thickness of the slurry reaches 3-5 mm. And finally, performing sand pressing and slurry collection by using steel plastering twice, eliminating sand holes, compacting the board surface, eliminating various residual uneven marks on the board surface, accelerating the evaporation of water on the board surface and facilitating early roughening.

When the concrete is made, water or cement is strictly sprayed on the surface of the concrete.

S9.4, napping the pavement:

1) napping: the surface texture of the newly-built cement concrete pavement is manufactured by a napping method, and the depth of the texture is not less than 0.4 mm.

2) The texture of the napping should be perpendicular to the central line or longitudinal construction joint of the road surface, the napping method is to use 1 aluminum alloy ruler as a guiding rule, use a brush to tightly cling to the guiding rule along the direction perpendicular to the longitudinal joint, and pull the brush forcibly and uniformly without stopping midway, so as to ensure that the texture is straight.

3) The brushed hair brush should be cleaned frequently to prevent hardening, and two persons should perform brushing simultaneously. A water tank is prepared during napping, and the hairbrush is cleaned and soaked in the water tank when not used.

4) The cement concrete pavement is artificially napped, the hairbrush is woven by a nylon wire/plastic pipe with the thickness of 3mm, the effective length of the nylon wire is ensured to be 12cm, and then the nylon wire and the plastic pipe are connected by a long bamboo pole. An aluminum alloy ruler with the length of 5 meters is used as a guide.

5) During napping, a ruler is often used for checking the distance between the napping texture linearity at the two ends of the plate and the pavement slab joint so as to ensure that the texture linearity is parallel to the pavement slab joint. There should be a certain overlap distance between the two brushes.

6) When the brush is used, the brush is prevented from falling, deforming and breaking, the brush is kept clean, cement mortar attached to the brush is removed every time the brush is pulled, the brush is prevented from hardening, and water on the brush is dried in a drying mode during hair pulling.

7) The napping time is determined according to weather conditions and the consistency of the slurry, and the principle is to ensure that the designed texture depth is met and the cement slurry does not flow or sand on the surface. The surface mortar is usually touched by hands, the surface mortar is not sticky, and the surface mortar can be napped when finger prints can be printed on the cement paste, and the surface mortar is generally controlled to be about 3 hours.

And S10, maintaining the pavement.

1) And (3) curing the concrete surface layer in time after final setting (no trace is shown when the road surface is lightly pressed by fingers), and curing the concrete by adopting non-woven geotextile and a curing agent. And (3) the pavement within a range of 75m from the central line of the runway is maintained by spraying a curing agent, and the rest parts are maintained by covering non-woven geotextile after pouring. The poured and formed concrete surface layer is forbidden to be stacked with any objects, and the skidded template or geotextile is required to be separated if the objects need to be stacked.

2) After the maintenance period begins, the pouring time, direction and length are marked by red paint on the pavement slab, so as to be beneficial to maintenance and operation. The curing time is determined according to the concrete strength increase condition, and the curing time is not less than 14 days.

And S11, slitting.

1) The time of cutting is determined by tests according to the air temperature and the strength of concrete during construction, the compressive strength of the concrete during cutting is preferably 6MPa-8MPa, the damage to the edge of the cutting seam and the loosening of stones caused by too early cutting seam are avoided, and the irregular shrinkage cracks of a concrete slab caused by too late cutting seam are also avoided.

2) A slitting process: when the joint is cut, the position of the joint is accurately measured, the cover is cut by the concrete and the concrete of the old pavement in a butt joint mode, and the joint cutting depth is 1/3-1/5 h (h is the plate thickness) of a false joint. And ejecting the mark by using an ink fountain as a cutting and cutting guide, and then cutting the pavement by using a cutting and cutting machine. In order to ensure the operation safety of the slitting machine, a slitting worker adopts a mode of pushing from the back of the slitting machine to perform slitting and a mode of prohibiting pulling from the slitting machine.

3) When the longitudinal joint and the transverse joint are cut, the longitudinal joint is cut according to the formed construction joint, so that double joints are prevented from being formed; when the transverse seam is cut, attention should be paid to the connection of the positions of the adjacent plate seams, the seam staggering is avoided, and the straight line is kept.

4) The slurry should be flushed clean immediately after lancing, and a filler should be used to fill the slot to prevent sand or other debris from falling into the slot.

And S12, demolding.

The corners of the concrete surface layer cannot be damaged during form removal, and the earliest form removal time after the concrete surface layer is formed meets the requirements of the following table. And after the formwork is removed, asphalt should be evenly coated on the side face of the concrete panel in time for maintenance, and white exposure cannot occur.

Earliest form removal time after concrete slab forming

Temperature of the scene	Earliest time (h) for concrete filling and pouring
		5 to 10 (10 excluded)	72
10 to 15 (15 is not included)	54
		15 to 20 (20 is not included)	36
20 to 25 (25 is not included)	24
		≥25	18

And S13, expanding the seam.

1) And (4) expanding the seam by mechanical cutting, completing the joint cutting, finishing the concrete curing period (28 d) and expanding the seam as soon as possible after the road surface is dried. The expansion of the joint is not suitable when the temperature is lower than 5 ℃.

2) And cleaning fillers, sand, stones, soil, laitance, maintenance compounds and other impurities in the gap before expanding the gap, and blowing the gap clean by a compressed air machine after cleaning.

3) The slot must be in a clean and dry state when the seam is filled.

And S14, adjusting the tie rod rib.

Before pouring the concrete of filling the storehouse, check whether the tie rod muscle of independent storehouse is straight, guarantee that all tie rod muscle are on a horizontal plane.

S15, laying a third felt (inner wall of filling cabin)

And a layer of felt is vertically laid along the lower surface of the pull rod rib of the independent bin. The width of the felt is 25cm, half of the felt is tightly attached to the old road surface of the filling bin, half of the felt is tightly attached to the side surface of the concrete of the independent bin, and the width of the lapping surface is not less than 10 cm.

S16 construction of filling concrete (independent warehouse)

Specifically, S7 → S9 → S10 → S11 → S13 is repeated.

Selection of materials and composition control

2.1 comforter concrete raw Material requirement

1) The cement is common portland cement, the strength grade is preferably 42.5 grade, tricalcium aluminate is less than or equal to 9.0 percent, tetracalcium aluminoferrite is more than or equal to 10.0 percent, free calcium oxide is less than or equal to 1.0 percent, alkali content is less than or equal to 0.6 percent, and all indexes meet the requirements of MH 5006-;

2) crushing stone: the 4.75-31.5 mm continuous graded macadam (the doping amount of 4.75-19 mm is 15%, the doping amount of 16-31.5 mm is 85%), the crushing value is less than or equal to 21%, and the mud content is less than or equal to 0.5%; tests show that all indexes of the product meet the requirements of MH 5006-2015 and JGJ 52-2006 specifications;

3) sand: river sand or river sand, alkali activity should not react, fineness modulus 2.6-3.2; tests show that all indexes of the product meet the requirements of MH 5006-2015 and JGJ 52-2006 specifications;

2.2 specification of felt

The total thickness of the felt is not more than 6 mm. Other indices are shown in the following table:

detecting items	Index (I)
		Water absorption (%)	≤3.0
Heat resistance	(85 +/-2) DEG C, 2h coating layer has no sliding, flowing and neutral bubbles
		Longitudinal tension (N/50 mm)	≥240
Flexibility	(85 +/-2) DEG C, no crack around phi 20mm rod or bent plate

Quality control standard of 'white plus white' maintenance and reconstruction maintenance construction technology

3.1 the height of the asphalt mastic mud for sealing the seams of the bin dividing of the old pavement is less than or equal to that of the old pavement;

3.2 strictly mixing according to the mixing proportion of the field test, checking the water content of the sand and the stone at any time, and adjusting the construction mixing proportion.

3.2 strictly performing slump inspection and controlling the water-cement ratio.

3.3 laying a first felt, strictly performing seam crossing and laying, wherein the width of each seam is 25cm, and the lap joint width is more than or equal to 100 mm;

3.4 laying the second felt vertically, wherein 25cm of the felt is on the old road surface, and 25cm of the felt is tightly attached to the inner wall of the template and is laid along with pouring, so that the felt is not too long, and the damage and the pollution of the felt are prevented.

3.5 the horizontal angle of the inserted tie bar slightly inclines upwards by about 5 degrees, so that the steel formwork is convenient to remove, and the tie bar is immediately adjusted after the steel formwork is removed.

3.6, controlling the galling time, and galling the surface of the concrete at proper time, wherein the galling depth is preferably 0.6mm-0.8mm.

3.7 the brush should be cleaned frequently to prevent hardening, and two persons should be simultaneously used for brushing. A water tank is prepared during napping, and the hairbrush is cleaned and soaked in the water tank when not used;

3.8, split seam and butt seam construction, namely, the split seam of the concrete of the covering quilt is completely consistent with the split seam of the old pavement, and the alignment error of the joints of the new pavement and the old pavement is controlled to be less than or equal to 30 mm.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, or direct or indirect applications in other related fields, which are made by the contents of the present specification, are included in the scope of the present invention.