In order to achieve a fair description of radon transport through concrete certain information is needed on the concrete structure, porosity and permeability, on processes causing the transport of radon, on radon’s interaction with environment, factors favouring the generation of radon, etc. The concrete characteristics (that depend on its composition and especially on the W/C ratio) which infl...

M. Naor (Ed.): TCC 2004, LCNS 2951, pages 336 352, February 2004. c © Springer-Verlag Berlin Heidelberg 2004. Abstract. We consider compositional properties of reactive systems that are secure in a cryptographic sense. We follow the well-known simulatability approach of modern cryptography, i.e., the specification is an ideal system and a real system should in some sense simulate this ideal one...

The performance requirements of the concrete of containment structures are mainly radiological protection, structural integrity and durability, etc. For this purpose, highperformance heavy density concrete with special attributes can be used. The aggregate of concrete plays an essential role in modifying concrete properties and the physico-mechanical properties of the concrete affect significan...

The type of lightweight aggregate and its volume fraction in a mix determine the density of lightweight concrete. Minimizing the density obviously requires a higher volume fraction, but this usually causes aggregates segregation in a conventional mixing process. This paper proposes a two-stage casting process to produce a lightweight concrete. This process involves placing lightweight aggregate...

Steel-concrete-steel (SCS) sandwich panels are composed of two steel plates with low thicknesses and high densities and strengths and one thick layer between both plates with low strength and density known as core that is composed of concrete. Cohesive material-epoxy resin or shear connectors are usually used to connect the plates to the concrete core. SCS sandwich composites are being develope...

Concrete, the solid that forms at room temperature from mixing Portland cement with water, sand, and aggregates, suffers from time-dependent deformation under load. This creep occurs at a rate that deteriorates the durability and truncates the lifespan of concrete structures. However, despite decades of research, the origin of concrete creep remains unknown. Here, we measure the in situ creep b...

Industrial activities in Iraq are associated with significant amounts of non-biodegradable solid waste, waste plastic being among the most prominent. This study involved 86 experiments and 254 tests to determine the efficiency of reusing waste plastic in the production of concrete. Thirty kilograms of waste plastic of fabriform shapes was used as a partial replacement for sand by 0%, 10%, 15%, ...

ABSTRACT  Introduction: Recently uses of medium and high energy x-rays has been increased in Iran and radiotherapy centers along with a variety of accelerators have been installed in some provinces. In the other hand there is no sufficient skill in designing and making radiotherapy treatment rooms. This study was conducted to evaluate the efficacy of different m...

an application of aerated concret (foam concrete) was experimentally studied. in this study the compressive strength of the proposed concrete was measured the effect of parameters such as aggregate size of broken stone, quantity of cement and various densities were exprementally studies, and the best mixture was select.these prepared mixtures are practically useful to optimize the consumption o...