Siavash Sajedi

New Formulation of Compressive Strength of Preformed-Foam Cellular Concrete: An Evolutionary Approach

AbstractIn the present study, new empirical models are derived to predict the compressive strength of preformed foam cellular concrete using volumetric and weighted approaches. The proposed models ...

Time-Dependent Reliability Analysis on the Flexural Behavior of Corroded RC Beams before and after Repairing

It has been recognized that the quantitative performance evaluation of corroded reinforced concrete (RC) structures could aid in developing effective repair strategies. However, the current performance evaluation only focuses on the ultimate strengths criteria and do not consider the serviceability requirements. To consider both criteria and to facilitate the analysis, an analytical procedure is proposed for predicting the load-deflection behavior of intact and corroded RC beams. The corrosion effects considered here include the effects of corrosion on the area and yielding strength of the rebars, and the bond stress-slip behavior at the steel-concrete interface. The proposed procedure is then utilized to evaluate the time-dependent reliability of an RC beam with and without repair in terms of flexural strength and deflection performances. The effects of relative humidity and mixture design are also studied.

Performance Evaluation of Different Repair Concretes Proposed for an Existing Deteriorated Jetty Structure

Performance of different cementitious repair materials is studied as part of an ongoing repair project on an existing reinforced concrete jetty in harsh environment of Persian Gulf. Concrete repair materials with different cementitious binders including ordinary portland cement, silica fume, and ground granulated blast furnace slag were tested. Different performance criteria such as mechanical properties, durability characteristics, and dimensional compatibility with substrate concrete were studied according to a proposed rational approach. It is concluded that a repair technique containing ternary pozzolanic materials has the best performance and could be proposed for marine environment.

Inverse Analysis Method for Concrete Shrinkage Prediction from Short-Term Tests

ACI Materials Journal, V. 109, No. 3, May-June 2012. MS No. M-2011-019.R1 received October 13, 2011, and reviewed under Institute publication policies. Copyright

Reliability-Based Multiobjective Design Optimization of Reinforced Concrete Bridges Considering Corrosion Effect

AbstractChloride-induced corrosion is known as the dominant cause of premature damage in reinforced concrete (RC) bridges in the United States. However, the current corrosion management strategies ...