To increase the resistance to fungal corrosion and improve performance of concrete cement stone, it is proposed introduce calcium stearate active metal nitrates in an amount 0.5% by weight into mixture at manufacturing stage. determine degree damage stone microorganisms Aspergillus niger, porosity, density, water absorption strength were determined. It has been found that introduction a hydroph...

there is a worldwide interest in using fibers of different types in concrete mixtures. in this regard, as the use of pet fibers has gradually increased during the last decade, this study aims to investigate the effects of pet fibers on the mechanical properties of hardened concrete and the workability of fresh concrete. to this end, different contents of pet fibers (pc= %0, %0.5, %1 and %1.5) a...

one of the main factors of premature deterioration of concrete structures is the corrosion of reinforcements. chloride penetration of concrete is one of the main reasons of this phenomenon. therefore, to have durable structure, it is necessary to have concretes with low permeability.there are various methods to evaluate permeability of concrete. finding a relationship between them can be useful...

By increasing the demolition of old concrete structures and the interest of civil industries to consume cheaper materials, using Recycled Concrete Aggregate (RCA) can cause environmental protection and decrease the construction costs. On the other hand, the high potential of Recycled Aggregate Concrete (RAC) in concrete industry was established by extensive experimental researches were performe...

While the Local Density Approximation LDA+U method is well established for Mott insualtors with well localized orbitals, its application to weakly correlated metals is questionable. By extending the Stoner approach to LDA+U, we show that LDA+U enhances the Stoner factor, while reducing the density of states. The most important correlation effects in metals, fluctuation induced mass renormalizat...

reactive powder concrete (rpc) is an ultra high performance concrete which has superior mechanical and physical properties. the rpc is composed of cement and very fine powders such as crushed quartz (100–600 μm) and silica fume with very low water/binder ratio (w/b) (less than 0.20) and super plasticizer (sp). the rpc has a very high compressive and tensile strength with better durability prope...