As we all know, asphalt pavement construction is a complex system project. Some projects are affected by the construction level, internal factors and external environment. During the construction process, asphalt mixture pavement appears red, moving, white and other abnormal phenomena, which not only affect the apparent quality of asphalt pavement, leaving hidden dangers for the internal quality, but also affect the durability of asphalt pavement to varying degrees. Next, Jinan asphalt manufacturer will talk about the abnormal phenomena and prevention measures of newly paved asphalt mixture surface.
Asphalt is composed of hydrocarbons with different molecular weights and their non-metallic derivatives. It is a black or dark brown viscous liquid or solid at room temperature, which mainly plays a cementing role in asphalt mixture. Generally, the common asphalt mixture is black, and the modified asphalt is black and shiny. The surface reddening is mainly manifested in the asphalt film peeling off and reddening on the surface of coarse aggregate corners and fine aggregate particles after rubber wheel rolling.
The apparent state and color of asphalt mixture after construction are different due to different structure types. SMA has a lot of asphalt mortar. Generally, rubber tyred rollers are not used, and the surface is less red; AC, Superpave dense graded asphalt mixture is mainly rubbed by rubber wheel roller, and under the action of repeated rubbed rubber wheel at high temperature, the surface is prone to reddening; Although ATB asphalt stabilized macadam is a dense asphalt mixture, it generally uses ordinary road petroleum asphalt. In addition, the grading is coarse and the asphalt stone ratio is small, so there is less red phenomenon.
The redness is mainly caused by the poor adhesion between asphalt and aggregate, and is related to the nature of the material itself, construction technology, etc. If multiple factors overlap, it will lead to serious redness on the surface and asphalt film peeling, which will directly affect the apparent quality of the pavement, and at the same time leave a quality hazard for the later use performance.
Whitening of bridge deck
With the continuous evaporation of water, white soluble substances appear white after drying. With the passage of time, under the repeated action of rain and vehicle load, the internal hydration and scouring effect are increasingly intensified, and serious grout pumping occurs in a short period of time, which eventually leads to local potholes and looseness of the bridge deck asphalt pavement, which brings great potential safety hazards to driving and greatly shortens the service life of the short circuit surface.
Whitening of the bridge deck mainly occurs after continuous rainfall, and it is manifested as local seepage in the early stage. Generally, the bridge expansion joints appear early, followed by relatively small longitudinal slopes, curved bridges and high sections. For single width two lane bridge deck asphalt pavement, it usually appears on the inner side of the high side, and the carriageway is prone to local whitening; In the middle lane of a single three lane road, the whitening phenomenon is generally more prominent. Whether the longitudinal slope is large or the straight section and curved slope bridge occur evenly, the probability and distribution range of the occurrence are larger and earlier than those of a single two lane road.
The parts where the asphalt pavement is prone to whitening are prone to ponding, the rainwater stays for a long time, there is more free water in the structure, the drainage is not smooth, and the heavy vehicle load and dynamic water scouring are frequent. These conditions aggravate the occurrence of whitening and pumping of the asphalt pavement on the bridge deck.
The reasons are, on the one hand, frequent rainfall and discontinuous construction of each structural layer during the construction period, on the other hand, large porosity and permeability coefficient of asphalt pavement itself, on the other hand, related to asphalt mixture characteristics, construction level and quality control measures, and secondly, directly related to bridge deck waterproof and drainage design, temporary drainage measures, etc.
New phenomena and problems arising in the construction of asphalt pavement shall be seriously treated, and technical measures for rectification and treatment shall be taken in time. It is an effective measure to ensure the apparent and internal quality by following the whole life cycle concept of asphalt pavement and constantly strengthening the quality management of construction details and construction process. Please come to our website for any questions http://www.ycgjglcl.com Message consultation!