I. Overview of the Project
Project name: Huang
Project location: Huang
Project overview: The starting pile number is yellow, and the ending pile number is yellow. The red line of the road is yellow meters wide, the design speed is 50km/h, and the section layout is: 5.0m (sidewalk)+5.0m (non-motor vehicle lane)+4.0m (non-motor vehicle lane)+12.0m (motor vehicle lane)+8.0m (median).
1, acceptance specification and implementation
Code for Construction and Acceptance of Urban Road Subgrade Engineering (CJJ44-9 1)
Code for Construction Acceptance of Fly Ash and Lime Pavement Base (CJJ44-97)
Code for Construction and Acceptance of Asphalt Pavement (GB50092-96)
Standard for Quality Inspection and Evaluation of Municipal Road Engineering (CJJ 1-90)
2. Cross section design
The asphalt concrete pavement is a one-way cross slope with a slope of 1.5%, and the granite sidewalk is a one-way cross slope with a slope of 2.0%.
3, soil subgrade design requirements
Farming or muddy soil containing humus shall not be used for subgrade filling. The compaction thickness of each layer of soil is controlled at about 25cm, and the slag is 60cm. The compactness (heavy technical standard) of soil subgrade shall meet the following requirements:
Under the road trough: 0-80cm 95%
& gt92% is less than 80cm.
95% is in the excavation and zero-fill area of 0-30cm.
4. Pavement structure design
Expressway:
4 cm fine-grained asphalt concrete pavement
8cm coarse-grained asphalt concrete bottom layer
20cm5% cement stabilized macadam base
20cm4% cement stabilized macadam base
150cm slag cushion
Non-motor vehicle lanes:
3cm fine-grained asphalt concrete pavement
5cm coarse-grained asphalt concrete base
20cm5% cement stabilized macadam base
18cm graded macadam subbase
150cm slag cushion
Sidewalk:
5cm Wulian red granite pavement
3cm cement mortar
15cm20 plain concrete
15cm5% cement stabilized macadam
5. Main projects and alignment
The starting and ending pile number of this project is yellow, which intersects with Qinlu Road. The south side of the Yellow Road is the Hong Kong Bus Station, while the north side of the Yellow Road is the Hong Kong Bus Station. The intersection coordinates are Huang's harbor bus stop.
1, north K0+000-K0+000
2. South K0+000-K0+000
3. South K0+000-K0+000
4.K0+000-K0+000 north side
5. South K0+000-K0+000
6.K0+000-K0+000 north side
Second, the survey lofting
1, according to the design centerline and well location, set out the site axis and temporary leveling points, and set up the climbing piles of each axis after review. Lay a water-stable layer.
Third, the construction equipment and machinery
1, general machinery
Serial number name unit quantity remarks
1.5 ton Jiefang truck 2 cars
2 Jinbei vans 1
3 single bucket excavator and bulldozer platform 1
4 Welding machine platform 2
5 level, theodolite 1
6 submersible pump platform 2
Fourth, subgrade construction
1, general requirements:
Before filling subgrade construction, do a good job of site rolling (60cm slag), and at the same time, the compactness, transverse slope, width and thickness of the basement shall meet the following requirements:
2, subgrade filling
(1) After filling, the slag base will be rolled, and after reaching the compactness, the water-stabilized macadam can be paved with the approval of the supervision engineer.
Verb (abbreviation of verb) pavement engineering construction
1, graded macadam subbase
(1) graded macadam subbase 18cm, which shall be paved and rolled on the non-motor vehicle lane at one time.
(2) Material requirements: the material has good water permeability, hard texture, no mud and no organic matter, and the crushing value is not more than 30%.
(3) After the graded macadam layer is rolled, the degree of compaction shall not be less than 98%.
2, cement stabilized macadam (4%, 5%)
Cement stabilized macadam;
(1) Cement stabilized macadam, the design is that 4% cement content is 20cm for the lower layer and 20cm for the upper layer, and 5% cement content is divided into upper and lower layers according to the design.
(2) The principle of layered construction is that after the lower cement stabilized macadam is constructed, the upper construction shall be carried out after the curing reaches the design strength.
(3) Material requirements of cement stabilized macadam
3- 1 cement
Cement stabilized macadam can use 3- 1- 1 ordinary portland cement and slag portland cement. It is forbidden to use hard cement, early hardening cement and cement deteriorated by external influences. The initial setting time of cement is required to be less than 6 hours.
3-2 Gravel
The maximum particle size of 3-2- 1 crushed stone is 3 1.5. It is suggested to grade according to the particle size of 9.5-3 1.5mm, as shown in the following table.
Mass percentage (%)(mm) of structural layer passing through the following square sieve holes
3 1.5 26.5 19.0 9.5 4.75 2.36 0.60 0.075
Grass-roots100 90-100 72-89 47-67 29-4917-35 8-22 0-7
3-2- 1 cement stabilized macadam mixture, the crushed value of macadam should not be greater than 28%, the needle content should not be greater than 15%, and the particles smaller than 0.6mm in aggregate must be tested for liquid limit plasticity index, requiring liquid limit < 28%, plasticity index < 9% and 3-3 water.
3-3- 1 River water and tap water can be used for general livestock.
(4) Gradation of cement stabilized macadam:
The gradation of cement stabilized macadam should be sent to the laboratory to configure test blocks according to the field materials, test results and actual conditions. The cement dosage and water cement ratio should be determined according to the pressure test strength, but the cement dosage can be adjusted to > 4% and 5%.
7-day immersion compressive strength of 4- 1 cement stabilized macadam base block ≥4.5Mpa.
4- 1- 1 Determine the cement dosage according to the laboratory test, and appropriately increase the cement dosage when mixing on site. No more than 0.5- 1%, and the dosage percentage shall be reported separately.
4- 1-2 in order to reduce cracks at the grass-roots level, three restrictions must be achieved. Limit the cement consumption on the basis of meeting the design; While reducing the silt content, limit the amount of fine-grained materials and mixed materials. Limit the water content according to the climatic conditions during construction.
The specific requirements are 4- 1-3: the cement dosage should not be greater than 6%. The particle content below 0.075 in aggregate gradation should not be greater than 5%, and the water content should not exceed 1% of the optimal water content.
(5) Construction principles of cement stabilized macadam:
5- 1 Mixing method in construction site:
5- 1- 1 mixing plant adopts the existing ballast subgrade, and two mixing plants are set up, with a total width of 30m and a length of about 150m-200m.
Six forced self-falling mixers are used for 5- 1-2 mixing, with three for each operation and two for each standby. Under normal circumstances, the daily output of each set is about 200m3-250m3, and each set is stirred 300 m3 from 6: 00am to 6: 00pm.
5- 1-3 Gravel and cement must be automatically weighed to control the mixing quality.
5-2 On the slag layer that has passed the acceptance test, retest the elevation again, check the change of settlement and smoothness, and check whether there are pits and looseness. If it exceeds the acceptance standard, it must be repaired in time.
5-3 Setting-out adopts bamboo piles to fix elevation, and bamboo piles are laid as bamboo piles (10m*6m).
(6) Trial paving: Before the official start of construction, trial paving shall be carried out at each site. After 2-3 days of trial paving, the supervisor is invited to participate in the summary of cement stabilized macadam. The contents summarized include: mix proportion of construction aggregate, determination of suitable thickness and loose paving coefficient for one paving, adjustment of construction method, etc.
(7) Delivery:
7- 1 The transportation of the mixture should avoid vehicle bumping to reduce the segregation of the mixture. In this project, 5T dump truck is used to drive back and forth in the accepted slag.
7-2 When the temperature is high, cover it when the transportation distance is long to prevent excessive water loss.
(8) Paving:
8- 1 Before paving, the subbase or base should be properly watered.
8-2 The mixture shall be paved by a professional paver.
8-3 Two pavers are used for the motor vehicle lane of this project, which are carried out in tandem and rolled in time.
8-4 Paving joints, two pavers in the fast lane should be carried out in tandem to avoid longitudinal joints. There is no longitudinal seam between motor vehicle lanes and non-motor vehicle lanes. There are transverse seams. According to the requirements of the design specification, the loose and flat part that meets the requirements will be drawn into a horizontal straight line, and the end will be controlled into a horizontal and vertical downward section. The paver will return to the compaction end to spread new mixture and continue to spread forward.
8-5 In order to ensure the bonding between the cement stabilized macadam base, when paving the upper layer, the lower layer should be wetted by water, and the slag should also be wetted by water appropriately to ensure the bonding between the cement stabilized macadam base and the slag.
8-6 When paving cement stabilized macadam, the subbase shall be inspected and accepted. If there is a loose surface,
(9) Rolling:
9- 1 Rolling requirements: first light, then heavy, first stable, then vibrating, and then rolled into the pavement by the roadside.
9-2 The primary rolling length is generally 50m-80m, and the rolling wheel tracks should overlap 1/2, with wheel width. When rolling, the procedures and processes of rolling in the test section should be followed.
9-3 Pay attention to full rolling, no smoke, no vibration and no movement.
9-4 Rolling procedure: stabilize first, then iron three rounds-light vibration rolling-revival rolling-and finally stabilize the pressure with rubber wheels. After pressing, there should be no trace to reach the specified degree of compaction.
9-5 rolling must be completed before the initial setting of the mixture.
(10) mixture curing:
10- 1 After each section of rolling is completed, the curing shall be started immediately. The maintenance method includes soaking the straw bag linen in water, covering it manually, and sprinkling water with a tractor modified sprinkler for maintenance. The curing time is not less than 7 days.
10-2 traffic should be closed during the health maintenance period.
10-3 after the paving and rolling of the upper mixture is completed, the topcoat oil shall be sprayed in time for maintenance, and the maintenance time shall not be less than 7 days. It is difficult to estimate, so you can cover it with linen for water spraying and curing, and then spray the oil layer after it meets the requirements.
10-4 In order to avoid dry loss after oil injection, a layer of stone chips or coarse sand should be sprinkled on the permeable oil.
1 1 other
1 1- 1 The construction season of cement stabilized macadam should be 0000 months, and rainproof measures can only be taken in rainy season.
1 1-2 the division of the construction organization operation section (including the test section) is divided into two working faces, east and west, according to the tasks undertaken by the construction team. The test section should be located in the east section, and the specific pile number and construction progress are to be determined.
1 1-3 asphalt pavement construction, it is best to carry out after the cement stabilized macadam reaches the design strength and the whole task is completed.
1 1-4 The quality index and rolling times of the mixture shall be implemented in principle according to the specified operation procedures. Such practical problems will inevitably appear in the construction. We must follow the supervisor's advice and make serious rectification to ensure the quality.
1 1-5 cement stabilized macadam, the supervisor put forward some valuable opinions, and seriously revised the construction organization design and cement stabilized macadam, which can be supplemented and revised according to specific conditions before construction.
FYI