In this paper, an optimum design of concrete-steel mixed frames under time-history loadings was formulated as optimization problem. The behavior a structure is different from the steel and reinforced concrete structures because vertically irregular in their mass, stiffness damping each part. Moreover, current codes available commercial software packages do not present solutions for such structu...

Deterioration of concrete, which is mainly due to ignorance of environmental and service conditions, causes considerable costs for the construction industry. With this in mind, in this paper, results of investigation into the major causes of concrete deterioration in the Urumie Lake are presented. For the purposes of this investigation, samples were obtained by mixing two types of cement (OPC t...

Portland cement concrete has been used extensively for many years as a construction material in bridges, buildings, highway pavements and other structures. Numerous structures and pavements that have been in service for decades illustrate the good durability and value of con­ crete when properly used in engineering construction. For example, the first concrete pavement built in the United State...

this paper describes a methodology in designing high-performance concrete for simply supported beams, using a hybrid optimization strategy based on a variable neighborhood search threshold acceptance algorithm. three strategies have been applied to discrete optimization of reinforced concrete beams: variable neighborhood descent (vnd), reduced neighborhood search (rns) and basic variable neighb...

This study reviews research showing changes in the performance of reinforced concrete structures and members caused by drying conditions, aims to contribute evaluating structural safety long-term use concrete. Additionally, build a consensus on physical properties materials after drying, review focused experiments intended produce uniform distribution moisture-induced material property interior...

In marine environment, the physical and mechanical performances of reinforced concrete members will vary distinctly with time, which reduces the safety of the structures. The main factors influencing the durability of reinforced concrete members include the deterioration of concrete, the reduction of reinforcing bar strength, the decrease of reinforcing bar area, the weakening of the bond stren...

in this paper, the possibility of using recycled aggregate (ra) and ground granulated blast furnace slag (ggbfs) to produce a structural concrete was studied by compromising strength to a lesser extent. hence an attempt has been made to study the strength and durability characteristics of the ggbfs-based recycled aggregate concrete. four different groups of mixes were designed by replacing natu...

an analytical nonlinear stress-strain model and a microscopic damage index for confined and unconfined concretes together with a macroscopic damage index for reinforced concrete (rc) structures under cyclic loading are proposed. in order to eliminate the problem of scale effect, an adjustable finite element computer program was generated to simulate rc structures subjected to cyclic loading. by...