The present paper deals with the use of polymeric matrix composite materials reinforced with carbon fiber as concrete shear reinforcement materials. Accordingly, cement specimens were manufactured and coated with various types of carbon fabrics and epoxy resin in liquid and solid form (paste). Additionally, composite materials of epoxy resin matrix reinforced with carbon fiber fabrics were manufactured. In all the specimens, the mechanical properties were estimated; the cement samples coated with composite materials of epoxy resin matrix reinforced with carbon fiber fabrics were tested for compressive strength, while the other specimens were tested for shear and bending strength. The specimens were subjected to artificial aging through heat treatment for 8, 12 and 16 days. During the process of artificial aging, the temperature in the chamber reached the range of 65–75 °C. These composite materials exhibited high mechanical properties combined with adaptability. Both an external deterioration of the materials as well as a reduction in mechanical properties during their artificial aging heat treatment were observed. This was shown in the specimens that were not subjected to artificial aging, with an applied compression strength of 74 MPa, and after the artificial aging, there was a decrease of ~7%, with the compression strength being reduced to 68 MPa.

Composite materials were created for usage as reinforcement and to protect the building envelope based on today’s global conditions such as climate change. Composite materials were manufactured using phenol-formaldehyde resin (case of resol) as a matrix, carbon fiber as reinforcement (7.5%v/v), and perlite (10%w/w) as a low thermal conductivity component, to combine high mechanical properties with good heat resistance and good thermal insulation properties. The structure of these new materials was examined through scanning electron microscopy (SEM) and elemental analysis (SEM-EDS). The addition of perlite (10%w/w) in the resite matrix (without fibers) increased the flexural and shear strength of the composite materials. On the other hand, the composite materials with fiber reinforcement show that the perlite reduces the flexural and shear strength due to the additional interfaces which were created. During heat treatment at 473 K, carbon fibers had the smallest weight loss followed by perlite while the resite matrix (i.e., the cured resol) shows the greatest weight loss. It is noted that the role of perlite is to stabilize the mass of the resite matrix during heat treatment. The composite material with carbon fibers and perlite is a heat-resistant material with only 2% weight loss at 473 K for 1 hour and shows a low coefficient of thermal conductivity, making it a new material in the direction of heat-insulating materials.

In this paper, the reinforcement of concrete combining composite materials with carbon, glass and aramid fibers is discussed. Accordingly, cement specimens reinforced with chopped carbon fibers were manufactured via the retrofitting method and coated using various different types of fabrics (carbon, glass and aramid), and epoxy resin systems were developed and studied using compressive strength tests. In addition, polymeric matrix (epoxy resin) composite materials reinforced with different types of fabric (carbon, glass and aramid (Kevlar^® 49)) were manufactured and their shear and bending strengths were measured. Before reinforcing cement specimens, all fabrics (carbon, glass and aramid (Kevlar^® 49)) were placed in a vacuum chamber and were processed via pre-impregnation. This specific reinforcing method significantly improved the mechanical properties of cementitious structures with compressive strength values that reached 81 MPa. In a similar way, the bending and shear strengths of the materials under study were measured at 405 MPa and 33 MPa, respectively.