Reviving Iran’s Heritage: The Role of Modern Materials in the Conservation of Historic Structures

Abstract

The integration of modern engineered materials into the conservation of Iran’s earthquake-prone and culturally rich historic structures has accelerated over the past decade. This article systematically reviews global and Iranian case studies to evaluate the compatibility, durability, and authenticity of advanced composites (e.g., carbon and glass Fiber-Reinforced Polymers [FRP]), Textile Reinforced Mortars (TRM), geopolymer adhesives, and nano-reinforcing materials. Using a PRISMA-inspired methodology, over 80 peer-reviewed sources were examined, of which 51 key studies were analyzed in-depth. Quantitative synthesis indicates that FRP wrapping can increase the in-plane shear strength of unreinforced masonry walls by up to 88% and ductility by 38%, whereas lime mortars reinforced with basalt fibers retain 95–98% of the masonry’s original breathability. Geopolymer grouts formulated with locally sourced volcanic pumice achieve compressive strengths of 12 to 15 MPa and water absorption rates below 20%, demonstrating excellent compatibility with historic stone substrates. However, the improper use of cementitious or impermeable coatings has resulted in irreversible moisture entrapment and façade damage at several Iranian heritage sites. We conclude that a balanced mechanical approach—prioritizing chemical and hygrothermal compatibility—enables effective deployment of modern materials while preserving authenticity. Practical guidelines and educational strategies are proposed for Iranian heritage professionals to ensure sustainable and minimally invasive interventions.