Flexible pavements: structure, design and performance for a durable road
During our journeys along roads and highways, we rarely stop to think about the complex structure that makes it possible for us to reach our destination safely. At Strinso, as civil engineering professionals with over 12 years in the road sector, we have confirmed that flexible pavements represent one of the most versatile and cost-effective solutions for road infrastructure construction.
Throughout our experience supervising projects across various regions of Latin America, we have learned that the key to success lies in three fundamental pillars: proper pavement design, rigorous construction, and timely maintenance.
What are flexible pavements?
Flexible pavements are multi-layer structures which deflect or flex in accordance with traffic loads or the loads to which they are subjected. They are characterised by their ability to recover their original shape, behaving as an elastic structure. Flexible pavements are used primarily in road surfaces, motorways, airport runways, and car parks with moderate to high traffic loads.
Flexible pavement design: the technology behind a durable structure
Flexible pavement design requires a balance between technical, economic, and environmental considerations.
A flexible pavement design must take into account factors such as:
Analysis of ground conditions: The geotechnical and geological characteristics of the soil must be evaluated, including groundwater presence, drainage, and other factors affecting pavement behaviour.
Definition of service requirements: Traffic levels, maximum loads, and climatic conditions to which the pavement will be subjected are established.
Materials selection: Appropriate materials are selected for each layer, taking into account resistance, durability, and cost.
Thickness calculation: The optimal thicknesses of each layer are determined to guarantee stability and durability.
Stress and deformation analysis: Mathematical models are used to evaluate pavement behaviour under different loads and conditions.
Rigorous construction, service life, and deterioration processes
Flexible pavements are designed for an average service life of 8 to 10 years. Strict quality control is very important to guarantee the use of appropriate materials, correct compaction, and the spreading temperature of the asphalt mixture.
During the service life of the pavement, the asphalt mixture undergoes two types of ageing:
- Short-term ageing: Occurs during production, transport, and application due to volatilisation of lighter asphalt components at high temperatures.
- Long-term ageing: A gradual process caused by oxidation through exposure to UV radiation, temperature, water, and traffic. The material hardens and becomes more susceptible to cracking.
Timely maintenance: pavement management systems
A Pavement Management System (PMS) is a set of systematic procedures aimed at creating a pavement inventory, assessing performance, and planning maintenance and rehabilitation interventions.
Routine maintenance
- Crack sealing: Application of asphalt materials containing polymer modifications, ideal for preventing water infiltration at initial cracks.
- Drainage system cleaning: Ensures effective water evacuation, preventing moisture-related deterioration.
- Repair of localised deteriorated areas: Carried out using localised patching techniques.
Periodic maintenance
- Surface treatments: Including slurry seals, which seal cracks, improve the surface, and extend structural service life.
- Milling and reinstatement: Removes the deteriorated surface layer and replaces it with new material.
- Thin overlay courses: A new thin asphalt layer placed to improve functional conditions.
Pavement management systems including PAVER®, Cartegraph®, HDM-4®, Agile Asset®, and tools such as PERS and AIRPORTS, guarantee effective outcomes for decision-making.
At Strinso we understand the importance of every stage in the lifecycle of flexible pavements. Our specialist solutions are designed to optimise performance and extend the durability of these essential road structures.
Author: Jessica Andrea Prada — Regional Marketing Responsible
