The expansion project
The new rest areas add a total of 161 stalls for articulated vehicles, refrigerated vehicles and campers.
Fratta Nord, covering approximately 6 hectares, has:
- 107 parking spaces for heavy vehicles;
- 8 stations for refrigerated vehicles;
- 11 car parks for coaches;
- 35 existing parking spaces retained.
Fratta Sud, developed on approximately 2.5 hectares, is home to:
- 54 stalls for heavy vehicles;
- 4 stations for refrigerated vehicles;
- 7 parking spaces for coaches.
The areas were completed with service buildings, showers, self-service laundry, areas for the recovery of damaged vehicles, video surveillance systems and real-time information systems on the occupancy level of the car parks. The overall investment was approximately 13.5 million euros.
The design solution
The design and construction were entrusted to the temporary association of companies made up of Brussi, Adriastrade and Impresa Coletto, while the filling of the flooring with i.tech CARGO was carried out by Ibuild Italia, a Heidelberg Materials company specialized in technical flooring.
The choice of grouted macadam derives from the experience gained in previous interventions and from the need to guarantee high load-bearing capacity and durability on a surface of approximately 14,200 m² intended for the continuous parking of heavy vehicles.
“In this project we were faced with approximately 14,200 m² of flooring intended for heavy traffic, to be created in compliance with particularly strict performance requirements in terms of load-bearing capacity, durability and executive quality”explains the engineer. Massimo Contadin, technical director of Impresa Coletto.
The executive phases of the flooring
The works began with the preparation of the subgrade by excavation, cold stabilization with binder and lime and subsequent formation of the embankment. In the parking areas for heavy vehicles the stratigraphy has foreseen:
- two layers of mixed cemented with different dosages of cement;
- a 10 cm high modulus bituminous conglomerate base layer;
- a 5 cm open graded layer intended for cement clogging.
Particular attention was paid to the executive quality and uniformity of performance of the entire platform. “Since this is a very large surface intended for heavy traffic, it was essential to guarantee uniformity and executive quality in every phase of the construction process”underlines Massimo Contadin. “The correct preparation of the installation surface represented an essential prerequisite for achieving the performance required by the project”.
Preliminary testing and choice of grain size
Before the definitive execution, a test field was created to verify compliance with the specifications, which required a degree of clogging of more than 80%.
To evaluate the behavior of the pavement and identify the most suitable configuration, two experimental bands approximately 20 m long each were created, characterized by different grain sizes of the drainage aggregate. After the laying of the material and the execution of the clogging by Ibuild Italia, sampling and subsequent coring campaigns were carried out aimed at verifying the degree of penetration of the clogging, the percentage of residual voids and the absorption of the material.
“The outcome of the tests highlighted good performance of the configuration created with 4/8 aggregate, which allowed good penetration of the clogging agent and a more effective reduction of residual voids compared to the alternative solution of 4/12″says Marco Sandri, Product Manager i.tech CARGO and Technical Director of Ibuild Italia.
The control activities also continued during the subsequent phases, including further core sampling aimed at ensuring compliance with the design requirements: “The validation was not limited to the initial test field, but continued for the entire duration of the works. This allowed us to promptly verify the behavior of the flooring and confirm the full compliance of the solution with the required requirements”observes PI Mirco Mazzon of Adriastrade.
The selected grain size was therefore adopted for the entire surface of the intervention, guaranteeing the achievement of the clogging level above 80% envisaged by the specifications.
What is i.tech CARGO
i.tech CARGO is a self-percolating cement mixture developed for the complete clogging of open graded bituminous conglomerates with high porosity. The technology allows to obtain a semi-flexible pavement that combines the characteristics of the cement matrix with those of the bituminous conglomerate, guaranteeing:
- high load-bearing capacity;
- puncture resistance;
- resistance to fuels, oils and aggressive agents;
- reduction of rutting, sinking and surface degradation.
The mechanical performances can reach values up to four times higher than those of traditional asphalt pavements. “This results in a flooring capable of withstanding high loads and intense traffic, particularly suitable for logistics areas, intermodal terminals, ports and car parks intended for heavy vehicles”explains Sandri.
Pose and exercise performance
The cement slurry was pumped and distributed over the surface using manual squeegees and subsequent mechanical finishing, favoring complete penetration inside the bituminous structure. To guarantee the required clogging level (>80%) a water/dust ratio of between 0.33 and 0.35 was adopted, with consumption in the order of 20–21 kg/m².
The flooring was put into service in less than 24 hours after installation. Among the main advantages of the solution:
- greater stability at high temperatures;
- reduction of permanent deformations;
- fewer maintenance needs;
- increase in surface albedo and reduction in summer overheating.
The intervention was completed with the creation of rainwater management systems, including two lamination basins of approximately 1,300 m³ (Fratta Sud) and 3,400 m³ (Fratta Nord), as well as a dedicated lifting station.
Overall, the new rest areas contribute to improving safety, reception capacity and quality of services along the A4, while the choice of grouted macadam paving with i.tech CARGO guarantees reliability and durability even in the presence of continuous heavy traffic.
For further information
heidelbergmaterials.it
