Guaranteed installation times and agile construction site management

The challenge

SEMAT, the Civil Construction and Industrial Services division of ATB Group, is a leader in the world of industrial and civil construction with over thirty years of experience and a proven track record in providing complete service packages for industry. P-Trex, the Business Unit of Fibre Net Spa, specialises in the design and manufacture of profiles, structures and fences in composite materials (GFRP), which are used in many industrial sectors as an upgrade to replace conventional materials. All the P-Trex profiles and structures are produced by Fibre Net Spa, a leading company in the market for structural reinforcement, strengthening, improvement and seismic retrofitting of existing buildings and infrastructures.

The construction site of the customer, a leading industrial group in the steel sector, required walkways to cover six tanks for the collection of brackish water intended for internal production processes. The site presented specific challenges, such as high corrosion resulting from the presence of brackish water and limited access to the tanks which prevented the installation of the structures directly on site. The work needed to be done urgently to allow the operators to access the construction site.

P-Trex’s solution

The design stage involved the implementation of an existing project and its detailed improvement, with sizing to real measurements and the addition of an anchoring system to allow the finished structure to be moved in a stable manner directly onto the prepared housing. The expected benefit had to coincide with a significant reduction in installation times.
Given the significant level of chemical aggression due to the presence of brackish water, the use of pultruded profiles in GFRP is the best choice thanks to their excellent mechanical performance together with high resistance to corrosion; factors that help to prolong the useful life of the structures and minimise their maintenance.
In addition to the engineering experience and detailed design skills, P-Trex’s support extends to all the work-related stages, providing the customer with advice during the design stage and support up to the final installation stage. This all-round approach is an important added value should the requirements change compared to the initial project.

The outcome

Compared to the initial project, the P-Trex team identified an excellent opportunity for improvement in the connections between the GFRP profiles by replacing commonly-used steel corner elements with a new, custom-built, corner, press-bent version, intended to give the required rigidity to the structure. After approving the definitive project, six walkways were produced consisting of pultruded profiles, steel connections and square mesh grating panels, with a railing on one side only, measuring 43 metres in length. All designed and manufactured in accordance with the UNI ENI ISO 14122-3 standard.
The walkways were all pre-assembled prior to shipping, except for the railings which were to be installed in situ at the destination site. The four-point anchoring system included in the project was tested in advance in-house to ensure that the entire structure could be lifted and handled.

Customer benefits

A well-organised, dynamic and sustainable work site where the tasks are perfectly synchronised is the dream of all wok site foremen. Thanks to the synergy between P-Trex and SEMAT, the work was carried out on time and as planned, with no unforeseen problems. The walkways supplied were ready assembled and the anchoring system significantly reduced the installation times.

Marco Mazza, work site coordinator, SEMAT:

“We established an excellent working relationship with P-Trex right from the start, thanks to the clarity and consistency demonstrated at all stages of the job, from the management of the request to the completion of the supply. The structure was delivered within the agreed time frames and the installation was carried out with the same consistency as seen in the assembly instructions.”