Cost and duration estimation is essential for the success of construction projects. The importance of decision making in cost and duration estimation for building design processes points to a need for an estimation tool for both designers and project managers. Particle swarm optimization (PSO), as the tools of soft computing techniques, offer significant potential in this field. This study presents the proposal of an approach to the estimation of construction costs and duration of construction projects, which is based on PSO approach. The general applicability of PSO in the formulated problem with cost and duration estimation is examined. A series of 60 projects collected from constructed government projects were utilized to build the proposed models. Eight input parameters, such as volume of bricks, the volume of concrete, footing type, elevators number, total floors area, area of the ground floor, floors number, and security status are used in building the proposed model. The results displayed that the PSO models can be an alternative approach to evaluate the cost and-or duration of construction projects. The developed model provides high prediction accuracy, with a low mean (0.97 and 0.99) and CoV (10.87% and 4.94%) values. A comparison of the models’ results indicated that predicting with PSO was importantly more precise.

Lightweight concrete manufacture has been aimed as a result of the use of boron waste which is aggregate of pumice, one of our natural resources, and a valuable industrial waste as a substitution material in different proportions (1%, 3%, 5%, 7%, and 9%). As a result of the study, it was aimed to obtain a water-resistant and lighter material which has higher properties than lightweight concrete in terms of physical and mechanical. The study was carried out as three stages. At the first stage, 90% of the pumice aggregate and 10% of the sand (Reference sample) were used and lightweight concrete was produced. At the second stage, boron waste at the rate of 1%, 3%, 5%, 7%, and 9% was used for pumice aggregate and the doped lightweight concrete sample was produced. At the last stage, tests were carried out for the determination of the physical and mechanical properties of lightweight concrete samples which were produced. For determination of mechanical properties, tensile splitting strength and compressive strength tests were performed. Additionally, specific gravity, water saturated unit volume weight, porosity, and capillary water absorption tests were made for the determination of physical diversities. It was found that the physical and mechanical properties of the material improved with the increase of boron waste in the consequence of this study. The best result was obtained with the boron waste substitution at the rate of 9%. Environmentally harmful boron wastes being used in the construction sector will contribute to sustainability by recycling the boron wastes.

In this study, it was aimed to develop properties of cement paste having standard properties and produce a graphene doped Polyvinyl Alcohol (PVA) and boron-based cement paste in this context. This type of special cement is mixed with PVA as polymer additive material so it can have a higher strength and sufficient elasticity per unit weight. Also, boric acid which can absorb neutrons having poisonous effect in nuclear reactions is added into the cement in order to minimize environmental disaster caused by a nuclear accident. Compressive and bending strengths were measured based on TSE tests of graphene doped PVA and boron-based cement paste. Then, samples were measured by Brunauer-Emmett-Teller Method (BET) and subjected to X-ray Diffraction (XRD). In XRD measurements, crystalline structure was observed in all materials. According to compressive strength tests, as the graphene amount increases compressive strength also increases, however in bending strength tests as the graphene amount increases bending strength decreases. Although the values of bending strength of samples produced decreased with increase of graphene content, these values were found to be above the standard values. In addition to boron, graphene admixture has a significant effect on material with its positive strength properties.

In this study, it is aimed to make improvements on blended brick (1) which is the first building material has a history of at least 10,000 years. To the blended brick which is a traditional material was kept constant at 5% the addition of fly ash which is industrial waste. It was aim of determine of the effect on the physical and mechanical properties of the blended brick using different ratios (5%, 10%, 15% and 20%) blast furnace slag. In the first stage, the production of fly ash-based blast furnace slag doped sample of blended brick was performed. In the second stage, a variety of experiments were applied to determine the physical and mechanical properties of the blended brick sample. As a result; It has been determined that unit volume weight and compressive strength decreases with the use of industrial wastes in blended brick production. They have occured an increase in porosity and capillary water absorption values. The use of industrial wastes in the production of blended bricks will contribute both improve the properties of the bricks and   the reduction of wastes left to the environment.

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