PSI - Issue 68

Eyad Shahin et al. / Procedia Structural Integrity 68 (2025) 238–244 E. Shahin et al. / Structural Integrity Procedia 00 (2025) 000–000

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1. Introduction In recent years, the construction industry has faced growing pressure to adopt more sustainable practices, particularly in developing high-performance materials. Engineered Cementitious Composites (ECC) have gained attention for their superior mechanical properties and durability, making them a promising alternative to traditional concrete. Often referred to as bendable concrete, ECC is a class of high-performance fiber-reinforced concrete (HPFRC) known for exceptional ductility, crack control, and strain-hardening behavior under tensile stress, Mahmoudi et al. (2022). While traditional concrete performs well in compression, it is limited in tensile strength due to its quasi-brittle nature, leading to the formation of wide, localized cracks that compromise the durability of structures. Fiber-Reinforced Concrete (FRC) was introduced to address these limitations by incorporating fibers to improve tensile strength and crack resistance. However, FRC generally softens after cracking, which does not fully resolve crack control issues in demanding applications. In contrast, ECC exhibits strain-hardening behavior, where numerous fine microcracks form under tensile stress, with crack widths typically below 100 µm. This characteristic allows ECC to maintain a tensile strain capacity exceeding 3%, Mahmoudi et al. (2022-2), distinguishing it from conventional FRC. The material’s superior performance is largely due to precise fiber-matrix interactions and the use of relatively low fiber volume fractions (1%-2%) Yu et al. (2018). This strain-hardening mechanism results in a dispersed cracking pattern, allowing ECC to better distribute stress across structures and prevent catastrophic failure. These properties make ECC particularly desirable for structures exposed to dynamic or cyclic loads, such as earthquake-resistant buildings, military structures, and infrastructure facing severe weather. In addition to its mechanical advantages, ECC is increasingly being recognized for its potential as a sustainable building material. The cement industry is a major contributor to global CO 2 emissions, prompting researchers to explore ways to reduce the environmental impact of ECC. One approach is to partially replace Ordinary Portland Cement (OPC) with supplementary cementitious materials (SCMs) such as fly ash or Ground Granulated Blast Furnace Slag (GGBS). These industrial by-products contribute to sustainability by recycling waste materials and enhance ECC’s long-term mechanical properties, including improved durability and resistance to aggressive environments. While fly ash has been extensively studied, interest in GGBS is growing due to its potential to reduce the carbon footprint of ECC and improve its compressive strength, tensile strength, and resistance to chloride penetration, making it particularly suitable for marine structures, bridges, and tunnels. Another avenue for improving ECC sustainability is the use of locally abundant materials like dune sand as a replacement for traditional silica sand. Widely available in desert regions, dune sand reduces the ecological footprint associated with extracting and transporting conventional aggregates. Using local materials also lowers production costs, making ECC more accessible for broader applications, especially in regions with limited access to traditional aggregates.

Nomenclature ECC

Engineered Cementitious Composites High Performance Fiber Reinforced Concrete

HPFRC

FRC OPC SCM

Fiber-reinforced Concrete Ordinary Portland Cement

Supplementary Cementitious Materials Ground Granulated Blast Furnace Slag Ultra-high Molecular Weight Polyethylene

GGBS

UHMWPE

SP

Superplasticizer water-to-binder ratio

W/B G30 G60 G90

ECC mix with 30% replacement of cement with GGBS ECC mix with 60% replacement of cement with GGBS ECC mix with 90% replacement of cement with GGBS

LVDT ASTM RCPT

Linear variable displacement transducer American Society for Testing and Materials Rapid Chloride Permeability Test