The uniaxial tensile stress-strain relationship of FRCM systems differs from that of FRP systems with organic matrices. In fact, in terms of behaviour, FRP systems occupy an intermediate position, between organic matrices - typically epoxy resins - and strengthening fibres, with linear elastic stress-strain relationship characteristics. Thanks to their innovative design with respect to the more established FRP systems, the stress-strain relationship of FRCM systems is characterised by an initial phase, during which the principal role is played by the contribution of the inorganic matrix/mortar plays, this is followed by a cracking phase within the matrix itself and, lastly, the residual contribution of the dry mesh. This behaviour is evidence of the pseudo-ductility of FRCM systems with respect to FRP systems, which translates to an advantage in terms of the local ductility of strengthening material when applied to the structural element on which the work is to be carried out. This local ductility also has positive effects when used to determine global system ductility, an approach applied to all the structural elements that need to dissipate energy and possess the capacity to deform when subjected to high load conditions, for example, seismic activity.

In order to compare the deterioration of the mechanical performance of concrete elements (reinforced and unreinforced) in response to temperature increases, flexural strength was selected over compressive strength as the significant parameter, since it is more sensitive to deterioration cause by heat. As can be seen in the graph on the right, as the temperature rises and, in particular, once it exceeds 130°, there is a noticeable deterioration in mechanical performance. While they are also affected temperature increases, FRCM strengthening systems retain their efficacy in terms of the increase in flexural strength with respect to unstrengthened concrete at the same temperature. With respect to ambient temperature, the strengthening system is able to counter the phenomenon of de-cohesion between aggregates and cement paste, which is the cause of loss of strength of unstrengthened concrete.

DT 200 R1 2013 (National Research Council) underlines how, as temperatures rise, epoxy resins begin to transition from a glassy to a visco-elastic state, resulting in deterioration of their adhesive properties and, hence, the mechanical performance of the FRP system. Moreover, in order to determine the environmental temperature at which the strengthening is efficacious, it is necessary to subtract 15° from the glass transition temperature of the resin (Tg) declared by the manufacturer in the technical specification. This means that, if the declared value of Tg is 50°C, the maximum environmental temperature at which the efficacy of the FRP strengthening system is guaranteed is 35°C.

When subjected to the reaction to fire test, in accordance with the applicable European standard, UNI EN 13501-1, Ruregold’s FRCM system was certified as at least Class B-s1,d0. This means that it does not cause toxic fumes and does not form incandescent drops that are potentially very hazardous for people during a fire. All FRP systems, on the other hand, have been certified in class "E", because they use an organic adhesive that contributes to the generation and/or propagation of fire and therefore require appropriate protection.

Ruregold’s FRCM (Fibre Reinforced Cementitious Matrix) strengthening systems maintain the specified performance properties independently of the Relative Humidity (RH) and the environmental temperature, in contrast to FRP systems, which only guarantee such properties under standard thermo-hygrometric conditions (20°C and 50% R.H.) The results of a durability test carried out at the ITC-CNR Laboratory of S. Giuliano Milanese show how much environmental conditions influence the mechanical performances of FRP structural strengthening systems, as can be seen from the graphs on the right. Results similar to the ones obtained at the ITC-CNR Laboratory were also obtained at MIT in Boston and the University of Edinburgh. The experimentation has demonstrated that, in the case of FRP systems, the presence of moisture on the surface of the structure modifies the type of break from "cohesive", i.e. within the support, to "adhesive", i.e. At the interface between the support and the strengthening. It has also been observed that prolonged exposure to moisture causes progressive deterioration of mechanical shear resistance and flexural strength, which tends to accelerate as the temperature increases in the interval between 73-104°F (23-40°C).