International Concrete Abstracts Portal

Engineered cementitious composites (ECC), a prominent innovation in the realm of concrete materials in recent years, contain a substantial amount of cement in their composition, thereby resulting in a significant environmental impact. To enhance the environmental sustainability of ECC, it is plausible to substitute a large portion of cement in the composition with fly ash, a by-product of coal-fired power plants. In recent years, there has been increased research in ECC containing high-volume fly ash (HVFA) binders and its wider application in construction practices. In this particular context, it becomes imperative to review the role of the HVFA binder in ECC. This review first examines the effects of incorporating an HVFA binder in ECC on fiber dispersion and fiber/matrix interface behavior. Additionally, mechanical properties, including the compressive strength, tensile behavior, and cracking behavior under loading, as well as durability performances of HVFA-based ECC under various exposure conditions, are explored. At last, the review summarizes the research needs pertaining to HVFA-based ECC, providing valuable guidance for future endeavors in this field.

Engineered cementitious composites (ECC) represent a significant innovation in construction materials due to their exceptional flexibility, tensile strength, and durability, surpassing traditional concrete. This review systematically examines the composition, mechanical behaviour, and real-world applications of ECC, with a focus on how fiber reinforcement, mineral additives, and micromechanical design improve its structural performance. The present study reports on the effects of various factors, including different types of mineral admixtures, aggregate sizes, fiber hybridization, and specimen dimensions. Key topics include ECC’s strain-hardening properties, its sustainability, and its capacity to resist crack development, making it ideal for high-performance infrastructure projects. Additionally, the review discusses recent advancements in ECC technology, such as hybrid fibre reinforcement and the material’s growing use in seismic structures. The paper also addresses the primary obstacles, including high initial costs and the absence of standardized specifications, while proposing future research paths aimed at optimizing ECC’s efficiency and economic viability.

Coastal reinforced concrete bridges are critical infrastructures, yet they face significant threats from corrosion due to saline environments and extreme loads like wave-induced forces and seismic events. This state-of-the-art review examines the resilience of corrosion-damaged RC bridges under such conditions. It compiles advanced methodologies and technological innovations to assess and enhance durability and safety. Key highlights include synthesizing loss estimation models with advanced reliability methods for a robust resilience assessment framework. Analyzing catastrophic bridge failures and environmental deterioration, the review underscores the urgent need for innovative materials and protective technologies. It emphasizes advanced analytical models like Performance-Based Earthquake Engineering (PBEE) and Incremental Dynamic Analysis (IDA) to evaluate combined impacts. The findings advocate for engineered cementitious composites (ECC) and advanced sensor systems for improved real-time monitoring and resilience. Future research should focus on developing comprehensive resilience models accounting for corrosion, seismic, and wave-induced loads to enhance infrastructure safety and sustainability.

Chloride threshold values for steel reinforcing bars in reinforced concrete under the effect of varying temperatures and extended long-term conditions in hot climate are investigated. This investigation covers a gap in the current codes, including ACI 318, where the effect of temperature on the chloride threshold is not addressed. A total of 96 concrete specimens reinforced with carbon steel reinforcing bars sourced from two manufacturers were cast with different chloride contents and exposed to four temperatures of 20, 35, 50, and 65°C (68, 95, 122, and 149°F) for a period of more than 2 years. The chloride threshold values were determined based on corrosion potential, corrosion rate, and mass loss at the end of the exposure period. The results of the three techniques showed a consistent trend of significant dependency of the chloride threshold value on temperature. The average water-soluble chloride threshold values based on mass loss were found to be 0.77%, 0.72%, 0.47%, and 0.12% by weight of cement for temperatures of 20, 35, 50, and 65°C (68, 95, 122, and 149°F), respectively. These findings are significant as they showed a dramatic drop in the chloride threshold values at high temperature. This research highlights the need for reassessment of ACI Code limits considering hot climate.

This experimental study investigates the influence of flexural cracks and punching shear failure inclination on double-headed studs anchorage within the critical perimeter. The research also explored the technical feasibility of using synthetic coarse aggregates from bauxite residue as a sustainable alternative in structural concrete production. The results showed that the overall structural integrity is impaired at 40 to 50% due to flexural cracks at the critical perimeter of 2‧d (30°), however, the perimeter of 1.2‧d (45°) enhanced the shear reinforcement activation and shear strength up 15%, providing a balanced failure within the strengthening zone. Thus, an internal equilibrium of the concrete capacity design (IECCD) method was proposed to calculate the contribution of double-headed studs and accurate the codes of punching shear strength predictions in serviceability and ultimate limits states. In addition, synthetic aggregates performed similarly to natural aggregates, offering environmental benefits such as reducing the carbon footprint and production stages.