International Concrete Abstracts Portal

This study employs advanced nonlinear finite element modeling to investigate Interface Shear Transfer (IST) behavior in RC connections, a crucial factor for bridge durability and safety. The research examines shear transfer mechanisms at the interface between precast girders and cast-in-place deck segments through three experimental methods: beam, push-off, and Iosipescu four-point bending tests. FE simulations evaluated stress distributions, IST capacity, and failure mechanisms. Validation against experimental data shows that the Iosipescu test provides the most accurate representation of IST behavior, exhibiting a stress distribution error margin of only 1%, closely aligning with observed failure patterns. In contrast, the push-off test showed a 30% deviation from empirical data, indicating reduced accuracy in predicting real-world IST behavior. These findings highlight the importance of incorporating the Iosipescu test into IST evaluation protocols, as its greater precision enhances design methodologies for concrete bridges, reduces structural failure risks, and informs future updates to IST-related codes.

This study investigates the impact of air-entraining admixtures (AEA) on mortar performance, focusing on fresh-state and hardened-state properties critical to durability and engineering applications. Ten distinct mortar mixtures were analyzed, following guidelines established by EFNARC (European Federation of National Associations Representing Producers and Applicators of Specialist Building Products for Concrete). AEAs were introduced at varying proportions (0.01–0.5% of cement weight) to evaluate their effects on intrinsic properties (density, void ratio, water absorption), rheological parameters (plastic viscosity, yield stress), and mechanical characteristics (compressive strength, ultrasonic velocity, modulus of elasticity).

Regression models were developed, yielding high predictive accuracy with R² values exceeding 0.98. Notably, ultrasonic velocity and modulus of elasticity demonstrated strong correlations with intrinsic properties across all curing ages. Similarly, compressive strength showed significant associations with rheological parameters, highlighting the influence of air content and flow behavior on structural performance. These findings offer precise quantitative models for predicting mortar behavior and optimizing formulations for enhanced performance.

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.

Corrosion of steel anchors in concrete poses a significant risk, leading to detachment, structural damage, and loss of anchor strength. To enhance the durability of structural elements involving anchors, the use of corrosion-resistant nonmetallic inserts could be a feasible alternative. This study presents an experimental investigation of the tensile and shear concrete breakout strength of a single cast-in fine ceramics insert (FCI). The tensile tests were conducted with FCIs located at the center and edge of concrete blocks, while the shear tests were conducted with inserts positioned at varying distances from the concrete block’s edge. The experimental program comprised 75 specimens of three different FCI diameters (FCI 1/2 in. [12.7 mm], FCI 5/8 in. [16.0 mm], and FCI 1 in. [25.4 mm]) with two different embedment depths for each type. The experimental results showed that FCI anchors performed satisfactorily, providing bearing capacity conservatively satisfying the values calculated by ACI equations for the concrete breakout strength.