The deterioration of road surfaces, often referred to as asphalt stripping and sanding, can occur due to the separation of bitumen from the aggregate and the asphalt surface. There are various methods available for restoring exposed asphalt, which we will briefly discuss below.
Moisture infiltration into the asphalt is one of the causes of asphalt bareness, resulting from a weak bond between the aggregate and bitumen. This weak bond eventually leads to surface destruction. However, exposure can also be caused by factors other than the penetration of tap water.
Several factors can contribute to asphalt exposure, including the use of inferior materials, the type and quality of bitumen, the heating process of bitumen, the presence of dust on aggregates and stone materials, the density during implementation, the percentage of empty space, the type of passing traffic, climatic conditions, and the lifespan of the asphalt.
Loss of bitumen from the surface of the grains due to inadequate resistance and adhesion can also contribute to asphalt exposure. The adhesion between bitumen and stone materials is a complex phenomenon that involves physical and chemical interactions.
Addressing each of the aforementioned factors requires different and specialized methods. Adhesion between bitumen and stone materials is crucial for asphalt stability, and improving the properties of the used bitumen plays a key role in enhancing adhesion.
One reason for asphalt sanding is the use of out-of-specification bitumen, which may not adhere well to certain stone materials and can be hydrophobic. Inadequate heating or compaction during asphalt execution, as well as insufficient bitumen content, can also contribute to sanding. Additionally, overheating the asphalt and excessive burning of the bitumen used can lead to sanding issues.
As previously mentioned, road sanding can occur due to various factors, one of which is the aging of bitumen and, consequently, asphalt. The aging process of bitumen leads to reduced penetration and increased hardness, making the bitumen brittle and causing it to separate from the surface. The presence of air voids in the asphalt pavement accelerates aging and early separation of stone materials. By increasing the thickness of bitumen around asphalt materials, aging can be minimized, delaying its effects.
To enhance the performance of vulnerable mixes, particularly in wet conditions, adhesive materials with anti-stripping properties are used. These materials, available in liquid or solid forms, help prevent the stripping of asphalt mixes.
Another method to reduce sanding is the application of fugsil, which involves spreading a thin layer of bitumen on the asphalt road surface. In addition to sealing the surface and filling small cracks, fugsil helps minimize sanding. CSS emulsion bitumens are commonly used for this purpose.
Depending on the extent and severity of the damage, the following options can be considered:
- Mechanical sweeping: The surface of the pavement is cleaned using a mechanical sweeper to remove foreign materials, stagnant water, loose and plucked grains. The damaged surface is then repaired with flood fog. The seal fog used should be a bitumen emulsion. Typically, the required amount of bitumen emulsion for this purpose ranges between 0.45 and 0.7 liters per square meter.
- Surface treatments: If the damage is significant, options such as surface asphalt, slurry seal, or a thin layer of asphalt concrete can be used for repair.
- Patching: In cases of severe localized abrasions, the damaged part is removed, and a deep or deep patch is applied. For extensive sanding, the remaining surface condition determines whether a protective asphalt or hot asphalt coating is necessary. If coarse-grained materials protrude more than 12 mm, a coating should be used instead of a seal coat.
These methods are selected based on the nature and severity of the damage, aiming to address the specific issues and ensure the longevity and stability of the road surface.
The advantages of using adhesive materials
Using adhesive materials with anti-stripping properties in wet conditions offers several advantages:
- Improved bond strength: Adhesive materials enhance the bond between the bitumen and the aggregates, improving the overall bond strength of the asphalt mix. This increased bond strength helps prevent the stripping or separation of the bitumen from the aggregates, even in the presence of moisture.
- Enhanced durability: The use of anti-stripping adhesive materials improves the durability of the asphalt mix in wet conditions. It helps maintain the integrity and stability of the pavement by preventing the loss of bitumen and the subsequent deterioration of the surface.
- Reduced moisture damage: Moisture infiltration into the asphalt can cause significant damage over time, leading to cracks, potholes, and surface degradation. Adhesive materials with anti-stripping properties minimize the penetration of water into the asphalt mix, reducing the potential for moisture-related damage.
- Increased resistance to traffic loads: Wet conditions combined with traffic loads can impose additional stress on the pavement. The use of anti-stripping adhesive materials enhances the resistance of the asphalt mix to the detrimental effects of moisture and traffic, ensuring better performance and longevity of the road surface.
- Improved skid resistance: Wet conditions often result in reduced skid resistance, increasing the risk of accidents. Adhesive materials with anti-stripping properties help maintain the texture and frictional characteristics of the asphalt surface, improving skid resistance and enhancing road safety.
- Cost-effective maintenance: By preventing or minimizing the occurrence of asphalt stripping in wet conditions, the need for frequent repairs and maintenance can be reduced. This leads to cost savings over the lifespan of the pavement, as well as reduced traffic disruptions and associated expenses.
Overall, the use of adhesive materials with anti-stripping properties in wet conditions provides multiple benefits, including improved bond strength, enhanced durability, reduced moisture damage, increased resistance to traffic loads, improved skid resistance, and cost-effective maintenance. These advantages contribute to the longevity, performance, and safety of the road surface in challenging wet conditions.
ATDM CO is a reputable manufacturer and exporter of Bitumen 60/70 and Bitumen 80/100. We specialize in offering high-quality bitumen products in various packaging options, including drums, bags, and bulk quantities. Our product line consists of three distinct quality grades: premium, second, and third types. Each grade is produced with meticulous attention to detail, utilizing advanced facilities and processes.
Our diverse range of options is designed to cater to the specific needs and volume requirements of our customers. Whether you require a smaller quantity for a specific project or a larger bulk order, we have the flexibility to accommodate your demands.
At ATDM CO, we prioritize product quality, reliability, and customer satisfaction. Our bitumen 60/70 is manufactured to meet international standards, ensuring optimal performance and durability in various applications. Currently, we have supplies in three countries of the United Arab Emirates (Dubai), Panama and Singapore are available. We take pride in delivering exceptional products that meet the diverse needs of our valued customers, both domestically and internationally.