Changsha Xiangtan Zhangjiajie Hengyang Jishou Yueyang Bridge Deck Construction and Poured Steel Bridge Deck Construction and Paving Company

Changsha, Xiangtan, Zhangjiajie, Hengyang, Jishou, Yueyang, Yiyang, Changde, Yongzhou, Zhuzhou, Loudi, Huaihua, Shaoyang and other places have long-term undertaking bridge deck pavement construction projects, poured asphalt pavement construction projects, steel bridge deck construction projects, Huanyin called: Liang, our company has a group of excellent construction management teams with rich experience in road construction. Based on the construction site and customer requirements, we will provide customers with the most professional and most favorable construction plans and quotations. Contact number: Beam
The characteristics of asphalt concrete determine its wide application in bridge deck pavement. In the actual paving of the bridge deck
Poured asphalt concrete, steel bridge deck paving, construction technology
, Foreword
Poured asphalt concrete has various advantages that make it It has become one of the most commonly used construction materials in steel bridge deck paving. Mastering the application of poured asphalt concrete will have a beneficial effect on construction.
, Advantages of poured asphalt concrete
.. Good waterproof effect. The density of poured asphalt concrete is very high, and its void ratio is close to zero, which makes the laid structural layer of poured asphalt concrete airtight and impermeable, which is different from other roller-compacted asphalt
It is incomparable to green concrete. In some bridge projects or core walls of hydraulic structures, poured asphalt concrete is used directly as a waterproof layer or as part of the waterproof structural system.
..Good durability. The near-zero porosity makes it almost impossible for external moisture and air to enter, thus avoiding the material aging caused by contact with air or moisture during use of asphalt concrete.
.3. Strong integrity. Since the poured asphalt concrete adopts a self-flowing paving process during construction, the pavement layer not only has a certain vertical resistance to deformation, but also has strong resistance in the transverse horizontal plane
The bonding force ensures the integrity of the pavement layer.
..Good strain performance. Poured asphalt concrete has a high asphalt content, which determines its good flexibility. To a certain extent, it can adapt to the bending deformation of the structural layer and rarely breaks or other damage
Phenomenon.
..Easy to construct. The biggest difference between poured asphalt concrete and roller compacted asphalt concrete is that poured asphalt concrete only needs to be simply leveled, without rolling, and can be formed after cooling. This avoids quality hazards such as aggregate segregation that may occur in roller-compacted asphalt concrete. It is precisely because of the convenience of construction of poured asphalt concrete that it has unique advantages in some special projects, such as sidewalks and other areas that cannot be compacted by machinery.
, Project Overview
..Construction Overview
Surface Waterproofing System Material Usage Table
Pave the lower layer - thickness 3, spread diabase ready-mixed gravel on the surface -/㎡
Buffer layer rubber asphalt sand glue thickness, approximately/㎡
Solvent-based binder-/㎡
Epoxy waterproof layer second layer of epoxy resin-/㎡, spread .3 gravel< br/>-/㎡
The first layer of epoxy resin㎡, spread .3 gravel 3-/㎡
..Construction plan
The bridge deck construction practice is planned to be from March to March , the total construction time is the proposal. If construction cannot be carried out due to weather reasons, the construction period will be postponed accordingly
.3. Organization of personnel, equipment and materials
The total number of people planned to invest in this construction section, management technology Personnel, operators, drivers, and migrant workers. The main equipment invested include: lathes and pouring paving equipment sets.
, Poured asphalt concrete construction
.． The mix ratio is determined. Pouring-type asphalt concrete is composed of various grades of mineral materials, mineral components, modified asphalt and fibers. The mineral materials are determined according to the "Technical Specifications for Highway Asphalt Concrete Pavement Construction" and design requirements. The grading ratio is (~):(3~):(~3):ore powder
:::, and the maximum oil-stone ratio is when the fluidity, penetration and penetration increment and other indicators
All meet the requirements.
..Mixing of cast asphalt mixture. The heating temperature of polymer-modified asphalt used in castable asphalt mixture is ~°C. Note: Since the pouring asphalt mixture has a high mixing temperature and a long mixing time, it has high requirements on the mixing capacity and high temperature resistance of the mixing plant. At the same time, the asphalt used in pouring asphalt mixture has high viscosity, and the mixture is easy to adhere to the equipment. Before the equipment is completely cooled, the adhering mixture should be thoroughly cleaned. Before production, the transport trolley, storage tank or unloading hopper should be cleaned and painted with isolation agent.
Mixing temperature control of the mixture: If the ore powder is not heated, the heating temperature of the stone should be about 3°C.
After the mixture is mixed, the discharge temperature is controlled according to the target of ~°C. Since the mineral powder content in the mixture is large, the mixing time of the mixture is relatively long.
.3. Transportation of pouring asphalt mixture. -Asphalt mixture needs to be continuously stirred and heated during transportation. Therefore, poured asphalt mixture uses special transportation equipment (called abroad).
Before feeding the material for the first time, its temperature should be preheated to about ℃. The mixed material being charged should be kept stirring, and at the same time, the temperature of the mixture should be raised to ℃ ~ ℃.
.． Paving of cast asphalt mixture. The pouring asphalt mixture is a self-flowing asphalt mixture that does not require rolling. To pave the - type pouring asphalt mixture, a special pouring paver is required.
.. Construction method of poured asphalt concrete
Addition of Trinidad Refined Lake Asphalt
For large-scale projects, use an asphalt pot with a rotating mixer to break into small pieces and dissolve, The required amount of straight run asphalt is then pumped into the asphalt pot and stirred and mixed. The dissolution temperature of lake asphalt should be less than ℃. In order to prevent the separation of asphalt and minerals, it must be continuously stirred and kept warm in an asphalt pot with a rotating mixer. For small-scale projects, the lake asphalt is crushed and dissolved, put into a heated mixing and thermal insulation tank according to each dosage, mixed with other mixtures, and discharged at the site. In order to be maneuverable, economical, and have a small temperature change of the mixture, the heated mixing and thermal insulation tank is mounted on a vehicle as a self-propelled heating mixing and thermal insulation tank truck.
Mixing
Usually an asphalt concrete mixer is used. Since a large amount of stone powder is used, and the mixing temperature of the mixture also needs to be high, in addition to aggregate dryers, large-scale projects require stone powder dryers. It is easy to obtain uniform stone powder with hot stone powder. Asphalt binder.
The stone powder dryer is composed of two concentric drums. The inner cylinder is heated by combustion. The stone powder is stirred between the inner and outer cylinders by the stirring teeth.
The stone powder is completely separated from the combustion, so the stone powder is It will not scatter to the outside world, and the stone powder is heated to ~℃. Since there is no stone powder dryer in small-scale projects, the only method is to reduce the production capacity of the mixer to increase the temperature of the mixture.
The mixing temperature of the mixture is specified to be ~℃. Since the asphalt concrete mixer has a bag filter,
it is very difficult for the mixture temperature to rise above ℃. In order to obtain the necessary construction performance, it should be used before use
/>The above-mentioned heating mixing and thermal insulation tank is heated twice. The temperature of the mixed material in the tank is raised for a second time to about ~
°C. When it reaches the required temperature and fluidity, it can be discharged.
, Analysis of countermeasures for existing problems
.. Raw material quality control
Asphalt should be made of high-quality domestic
or imported asphalt with good high and low temperature properties, anti-aging properties, and high viscosity. If conditions permit, various types of modifiers can be added to asphalt to improve base performance indicators.
The aggregates selected should be those with rough surface, hard stone, strong wear resistance, good embedding effect, and
good adhesion to asphalt. The gradation of the mixture determines the high-temperature stability and fatigue performance of the asphalt mixture, low-temperature crack resistance, pavement surface characteristics and durability, two contradictory properties, which restrict each other,
Taking care of one aspect of performance may degrade another aspect of performance.
.． Optimizing design
The focus of improving long-term performance should be to optimize the structural combination design and design the pavement surface layer based on the data obtained from the actual conditions of each road. Only such data can be more reasonable and suitable. Optimize the design of asphalt mixtures. Mineral mixtures should adopt a dense skeleton structure when designing. The optimal amount of asphalt should be carefully selected based on the functions required by the oil surface layer at different levels.
.3． Strength of subgrade
Compaction degree is an important indicator reflecting the strength of subgrade, and it is also the most economical and
effective technical measure to improve the strength and stability of subgrade. During construction, strict inspection and control must be carried out to ensure that it reaches the specified value. It has good compliance with the deformation of the steel bridge deck, has excellent integrity, and has excellent resistance to low-temperature cracking and fatigue cracking
.. Quality control during construction
The selection of asphalt is very critical. It is necessary to select asphalt that meets the requirements of the specifications, especially the penetration and ductility indicators of asphalt must be strictly controlled. The climate in construction mountains in the north has been warmer in recent years. Therefore, the asphalt grade should be low-grade asphalt within the specified range.
Special attention should be paid to the design of asphalt mixture proportions. Asphalt mixture mixing time, factory temperature, paving temperature, rolling molding and other temperature controls must be carried out strictly in accordance with the specifications. Reasonably arrange the construction period and avoid adverse weather conditions.
, Mix ratio design method
., Design indicators. The properties of poured asphalt mixtures and ordinary asphalt mixtures are different, so the mix ratio design of poured asphalt mixtures is different from ordinary mix ratio designs through Marshall design method or Bayern design method. The Ray design method mainly relies on the experimental values of Liuel's fluidity test, penetration and penetration increment tests as design goals, and evaluates the mix ratio through low-temperature bending tests, etc.
., gradation selection. The maximum nominal particle size of poured asphalt mixture is generally 3. , with a pass rate of 3 as the key mesh. The coarse aggregate content in the mixture is approximately , the fine aggregate content is approximately , and the filler content is approximately .
.Determine the initial mixture ratio. Screen the aggregate, test the gross volume density of the aggregate, and test the performance of the asphalt, surrounding. 3. Based on the similarities and differences in pass rates, three or more gradations are formulated.
., Determine the best mixture ratio. The three initial mixture proportions were prepared using modified asphalt
to prepare poured asphalt concrete, and the best mixture was determined through low-temperature bending experiments and other factors combined with local relevant climate conditions, traffic conditions
Mixing ratio