مختصر البحث:
Since ancient times, brick has been one of the most common materials used to construct buildings in Iraq: many extant ruins of historical and religious buildings attest to these being constructed from brick. Without reinforcement, however, masonry w…
Since ancient times, brick has been one of the most common materials used to construct buildings in Iraq: many extant ruins of historical and religious buildings attest to these being constructed from brick. Without reinforcement, however, masonry walls are prone to failure when subjected to loads in and out of plane, and the inability of such walls to withstand shear and bending stresses is primarily responsible for this problem. As it is common for heritage architecture to be erected using masonry structures, strengthening aging brick walls is necessary to prevent collapse and structural damage. In cases featuring historical and religious buildings, such as the Holy Shrine of Imam Ali, strengthening aging brick walls is crucial for preserving the related architectural heritage as well as retaining the site's religious and cultural significance. There are many technical and cost-effective ways to deal with the issues caused by failing masonry, though Fiber Reinforced Polymer (FRP) materials are considered to be one of the most efficient and effective solutions available. The advantages of FRP materials include their ease of application, light weight, and superior tensile strength. However, FRP materials tend to be expensive and effective only if used in appropriate configurations. This study thus sought to investigate a strengthening approach using FRP materials in different configurations to assess both ease of implementation and preservation of architectural appearance. This included evaluating the strengthening behaviors of configurations fabricated from FPR composites (CFRP and GFRP) in both sheet and strip form. Nine masonry brick specimens were thus made and tested by being subjected to load until failure. All masonry brick specimens were tested under two stress conditions, that is, with shear and flexural stresses. The specimens were identical with regard to dimensions and boundary conditions for each loading scenario, though the shear specimens were fabricated in a 1250x1250 mm format, based on ASTM E519M-15, while the flexural specimens were formed in 620x610 mm samples to meet the ASTM E518M-15 standard. In the shear test, the specimen strengthened using CFRP material on one full side of the brick specimen recorded the maximum benefit with regard to load capacity and shear stress (364.7% and 373.3%, respectively). All strengthening techniques (CFRB sheet, GFRP sheet, CFRP grid, and CFRP diagonal strip) significantly increased the ultimate deflections of the specimens, by 168.8%, 111.8%, 158.1%, and 93.5%, respectively. Testing the brick specimens with respect to flexural stress also revealed that strengthening using a CFRP sheet on the bottom of the specimen was more effective than other methods, achieving increases in ultimate load and deflection of about 168.8% and 169.6%, respectively. However, strengthening using a CFRP grid was also effective, with results close to those found in the specimen with CFRP sheet reinforcement with respect to ultimate deflection and in the specimen with GFRP sheet reinforcement with respect to flexural stress.
