Ampiamento tratto autostradale da Rimini Nord a Pedaso per la realizzazione della terza corsia
1
The efficient milling machines have made it possible to accurately respect both the prescribed milling depths and the narrow time window.
2
For the base and Binder paving, after topographical positioning of the project sections, our technicians positioned longitudinal planar guide wires to follow when laying the new pavement.
3
In the basic and binder laying phase, the rubber rollers took on a leading role: immediately after the passage of the paver, they proceeded with the initial compaction
4
The Vogele asphalt pavers and Bomag Asphalt Manager rollers played the lion’s share in the laying phase of the bitumen and binder base asphalt mixes.
5
Before the execution of the pervious, the levelling system with 3D robotic technology was used. With the definition “intelligent milling or 3D milling” we want to
6
Pesaresi has developed and certified a spreading machine for filler to be mounted on a wheeled tractor, to be used after the attack coat with modified emulsion.
7
In addition to the quality of the machines, the good training of the teams of operators is also an essential aspect for the success of the project.
8
During the laying of the wear carpet, where possible two simultaneous paver finishers were used
9
The laying of the pervious wear pavement took place by means of a rubber-coated vibratory finishing machine, equipped with a 12 m Big Multiplex system with three laser sensors.
10
The study of the mixtures for the construction of bituminous conglomerates meeting the characteristics dictated by the Special Tender Specifications
11
The bituminous conglomerate used in the processing was entirely produced in the plant owned by Pesaresi Giuseppe S.p.A
12
The transport of the bituminous conglomerate was entrusted exclusively to road trucks with covered body, guaranteeing average travel times of about 30/60 minutes from the place of loading

Extension works of the 3rd lane from North Rimini to Pedaso
concerning the A14 Bologna motorway
(Phase 1)

Concerning the Bologna – Bari – Taranto motorway.
Located in the Cattolica – Fano section. Lot 2 from Km 145 + 537 to Km 173 + 702

Description of the intervention

With reference to the extension works of the 3rd lane from North Rimini to Pedaso on the Bologna – Bari – Taranto motorway, located in the Cattolica – Fano stretch. Lot 2 from Km 145 + 537 to Km 173 + 702, in November of 2011, following a private negotiation, the “PENTAPOLI” Società Consortile a r.l. has entrusted Pesaresi Giuseppe S.p.A. with the supply and installation of bituminous conglomerates type Base 0/30 mod. hard and Binder 0/18 mod. hard.

The construction of the pavement in bituminous conglomerate on the stretches in extension of the motorway, took place on embankments – laying surfaces in mixed cement prepared by the Customer.

After topographical positioning of the road sections to trace the plano-altimetric dimensions of the new platform, before the laying of the bituminous conglomerate or at the same time as the laying of the first base layer, our workers proceeded to install longitudinal guide wires positioned at the height of the binder, so as to create for the operator in charge of guiding-adjusting the paver, both a longitudinal and transversal dimension and direction reference, able to determine thanks to it, the thickness of the intermediate strips necessary to cover the the entire width of the new platform, which in cases of fully asymmetrical expansion reached up to about 15.00 meters.
The road package for the project bituminous conglomerate, provided for a 0/30 base layer with hard modified bitumen of the total thickness, measured after rolling, of 25 cm, carried out by laying a first layer of the finished thickness of about 15 cm and a second layer of about 10 cm, taking care to offset the longitudinal joints by varying the width of the single strips. The spreading took place in layers in order to guarantee the correct compaction of the conglomerate and to guarantee the achievement of the percentage of voids declared in the prequalifications. For this purpose, the rolling of the conglomerate takes place through the simultaneous use of a static rubber roller brand Bomag BW27RH weighing 24 tons. and a vibrating iron roller brand Bomag BW174AD weighing 10 tons.

Before the execution of the second base layer, and of the binder, the attack coat was made by spreading acidic bituminous emulsion, then proceeding to trace the exact thicknesses missing to reach the expected thickness, identifiable by using transverse wires referring to the traced sections.

The laying of the binder took place by means of a single layer of the minimum projected thickness of 5 cm, longitudinally following the yard tracing threads, and transversely the dimensions further traced on the last base layer, between the individual strips, in order to correct any slight depressions and / or imperfections on the underlying layer, always paying maximum attention to the offset of the longitudinal joints. During the laying of the binder, the containment edge in bituminous conglomerate was created, where necessary, about 10 cm wide and about 15 cm high.

By means of padding, the existing road section was raised and re-profiled. These were organized by the client in several phases compatible with the progress of the work, in day and / or night work shifts. In the case of temporary paddings subject to opening to vehicular traffic, or in any case each time conglomerate floors made at different times are joined, the previous paving has been scarified in order to revive, clean and homogenise the point of attachment between the new and old bituminous conglomerate.

Subsequently, in February 2012, the Client “Pentapoli S.C.a R.L.”, extended the contract entrusted to us to the construction works of the pervious wear layer. The intervention was carried out in several stages:

  • 1st section, from Cattolica (Km 145 + 537 at the beginning of the lot) to Pesaro (Km 163 + 000, around Case Bruciate), north and south carriageway,
  • 2nd section, from Fano (Km 173 + 702 at the end of the lot) to Pesaro (Km 163 + 000 approximately), south and north carriageway.

Before laying the pervious pavement type, 3D milling was carried out to optimise the levels of the current state. The purpose is to level the laying surface of the pervious wear by scarifying the upper parts, or rather refilling the depressed areas with bituminous conglomerate. In this way, an optimisation of the project level is obtained and a leveling of the slight imperfections inevitably present on the binder plane, due to the execution of the same in several fragmented phases.

The surface thus obtained was perfectly cleaned with the aid of a sweeper, to be sprinkled first with a modified attack coat and then with filler, in order to prevent traction to the tire laying surface of the vehicles used for the transport and laying of the conglomerate.

The laying of the pervious wear pavement took place by means of a rubber-coated vibratory finishing machine, equipped with a 12 m Big Multiplex system with three laser sensors. The formation of the wear layer, on the previously leveled surface, took place by spreading at a constant thickness of 4 cm (rendered after rolling), with the aid of the altimetric control plan tracking, useful to correct further and any flatness defects still present.

Compatibly with the construction sites, the paving was organised over one or more work shifts so as to ensure longer stripes without recovery points and avoid foreseeable stops, which would have resulted in an inevitable cooling of the conglomerate. Where possible, two paver-side pavers were used at the same time, thus creating the “hot” joint of the two strips. For the longitudinal jointing of pavements carried out at different times, the attachment tooth has always been milled, so as to revive and regularise the same, while eliminating the most marginal part of the previous pavement.

Below, the most characteristic elements of the tender in question are reported by points:

1

Study and planning of the intervention

The efficient milling machines have made it possible to accurately respect both the prescribed milling depths and the narrow time window. The bituminous conglomerate was removed layer by layer, to separate the milled precious material and recycle it later.
2

The basic laying

For the base and Binder paving, after topographical positioning of the project sections, our technicians positioned longitudinal planar guide wires to follow when laying the new pavement. This tracking allows you to check the laying of the conglomerate at the exact project height at any time during the processing, determining in the case of laying in multiple layers, the exact thickness missing when reaching the height at each point of the road platform.
3

Kneading and sealing

In the basic and binder laying phase, the rubber rollers took on a leading role: immediately after the passage of the paver, they proceeded with the initial compaction, guaranteeing a good kneading and sealing effect, very important factors in demanding construction sites.
4

Vogele pavers and rollers Bomag

The Vogele asphalt pavers and Bomag Asphalt Manager rollers played the lion's share in the laying phase of the bitumen and binder base asphalt mixes. The Vogele pavers of Pesaresi Giuseppe Spa offer first-rate paving quality. The screeds achieve a high degree of pre-compaction in a very uniform way over the entire paving width. Bomag Asphalt Manager is the intelligent regulation system that manages the available potential according to the real need, always providing the maximum possible compaction power.
5

Levelling system with 3D robotic technology

Before the execution of the pervious, the levelling system with 3D robotic technology was used. With the definition "intelligent milling or 3D milling" we want to identify the specific process that allows, with a normal road cutter, to optimize the milling thickness, regardless of the conformation of the existing road superstructure. The system includes components to be mounted on the milling machine and the use of a UTS [Universal Total Station] Robotised Total Station for driving the vehicle. The first phase of the work consisted in carrying out a plano-altimetric survey of the existing state of affairs for the entire road platform, with millimeter precision, in order to acquire all the imperfections of the pavement. We then continued with the installation of the cornerstones essential for subsequent 3D milling. The work was performed with robotic total stations. The relevant data was then imported into the road design software to develop an optimised 3D project with constant longitudinal and transverse slopes. The optimised project was created with the intention of milling the entire road surface in order to have the substrate perfectly level, without depressions of any kind. Finally, a 3D machine guide file was created for the Total Station (for inspection).
6

Quality equipment and machines

Pesaresi has developed and certified a spreading machine for filler to be mounted on a wheeled tractor, to be used after the attack coat with modified emulsion. This equipment allows to spread the right amount of filler on the bituminous emulsion, optimal to prevent adhesion to the laying surface of the tires of the vehicles used for the transport and laying of the conglomerate, all without creating a separation surface between the hand of attack and the top bituminous conglomerate layer.
7

Training of operator teams

In addition to the quality of the machines, the good training of the teams of operators is also an essential aspect for the success of the project. In order for our teams to be able to provide quality work, machine operators and paving foremen regularly attend refresher courses.
8

Two paver finishers side by side

During the laying of the wear carpet, where possible two simultaneous paver finishers were used, thus creating the "hot" joint of the two strips.
9

The laying of the pervious wear pavement

The laying of the pervious wear pavement took place by means of a rubber-coated vibratory finishing machine, equipped with a 12 m Big Multiplex system with three laser sensors. In the road construction sector, the requirements of precision and quality are becoming increasingly stringent. By aligning three ultrasonic height sensors it is possible to simultaneously scan a physical reference in several suitably spaced points. The levelling automatism calculates a virtual reference level on the basis of the detected measurements. The three ultrasonic sensors are fixed on a beam up to 12 m long. The new system is therefore able to easily recognize and compensate for large irregularities such as undulations in the ground. The system therefore works more precisely than a single height sensor.
10

The study of mixtures

The study of the mixtures for the construction of bituminous conglomerates meeting the characteristics dictated by the Special Tender Specifications, was carried out entirely in the testing laboratory inside Pesaresi Giuseppe S.p.A. and approved by Spea S.p.A., as a control body appointed by the Works Management.
11

The bituminous conglomerate

The bituminous conglomerate used in the processing was entirely produced in the plant owned by Pesaresi Giuseppe S.p.A Materials used: base 0/30 mod. hard; binder 0/18 mod. hard; draining wear; hypodrenant wear; wear 0/15 100% basalt bitumen mod. hard.
12

The transport

The transport of the bituminous conglomerate was entrusted exclusively to road trucks with covered body, guaranteeing average travel times of about 30/60 minutes from the place of loading to the processing area; since our site managers had previously determined the exact number of means of transport needed, the high-performance paver was able to express their full potential, making the most of the time available without any downtime.

Intervention specification

CONTRACTING AUTHORITY.
Company “AUTOSTRADE PER L’ITALIA S.p.A.”

CUSTOMER:
Temporary grouping of companies “PENTAPOLI” S.c.a.r.l.

AUCTION CRITERION OF WORKS:
Work in subcontracting

AMOUNT OF CONTRACT:
€ 23.840.000,00

WORK CATEGORIES:
OG3 € 23.840.000,00

START DATE AND FINISH DATE OF WORKS:
December 2011 – July 2014