Characterization and acceptance of composite materials 

Qualification of FRP and SRP composites

 

It is mandatory that Fibre Reinforced Polymer (FRP) and Steel Reinforced Polymer (SRP) composites, like all construction materials, are qualified in order for them to be included in the design and accepted in the construction site. The Guidelines “Linea Guida per la identificazione, la qualificazione ed il controllo di accettazione di compositi fibrorinforzati a matrice polimerica (FRP) da utilizzarsi per il consolidamento strutturale di costruzioni esistenti.” issued by the Servizio Tecnico Centrale (STC) of the Consiglio Superiore dei Lavori Pubblici (CSLLPP) provides instructions on the process for the qualification of FRPs, which includes documentation and experimental tests.
The Structures Research Group carried out the experimental tests required for the qualification of FRP and SRP composites produced and supplied by Italian industries. The activity included the manucafturing of the specimens (prismatic coupons), their artificial aging for durability tests, the execution of the tensile tests, and the preparation of the official test reports. Technical support was also provided to industrial partners during the process of verification by the Servizio Tecnico Centrale (STC).
The following artificial aging processes were performed in a climatic chamber with temperature and relatie humidity control:

• Immersion in saline solution (substitute ocean water prepared in accordance with ATSM D1141); specimens stored in tanks at 23°C;
• Immersion in alkaline solution (pH>12) of calcium carbonate; specimens stored in tanks at 23°C);
• Exposure to humidity, consisting in 38°C and 98% relative humidity (R.H.)
• Exposure to freeze-thaw cycles, consisting in one week of pre-curing at 38°C and 98% R.H., followed by 20 cycles of 4 hours at -18°C and 12 hours at 38°C and 98% R.H.

 

The Experimental Laboratory is recognized as Official Laboratory in accordance with art. 20 of the Law 1086/71.