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...

Climate change occasioned by the accumulation of greenhouse gases (GHGs) is now widely accepted as an issue which mankind needs to address. The starting point is necessarily the determination of all the sources of emissions during the life-cycles of the studied components. Post-calculation, the results ought to be presented to decision-makers in a clear manner so as to provide the basis on whic...

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...

Nowadays, concrete with strength higher than 50 MPa is utilized due to the ever increasing need for higher strength and prolonged healing properties. Despite the widespread use of high-strength concrete, only a few research projects have been conducted on the punching shear strength of high-strength concrete slabs. Reinforced concrete flat slabs are widely employed in structural systems. The lo...

the present study investigates the effect of different exposure densities on third grade iranian junior high school (ijhs) students’ efl development and retention. it also attempts to explore whether there is any differential performance due to type of post-exposure assessment tasks (recognition vs. written production). performances of five groups of learners receiving equal amount of exposure ...

In this paper a review is presented based on experimental studies done on high performance concrete. The compiled test data revealed distinct differences in the mechanical properties of normal, high strength and high performance concrete. Shape of the specimen ( cube, cylinder, beam etc), size of specimen, magnitude of temperature load applied on the specimen, percentage of fibers varied in the...

The main objective of this study is to evaluate the workability of fresh portland cement concrete while it is still in the mixing truck by determining fundamental rheological parameters (plastic viscosity and yield stress). Nine concrete mixtures with different values of yield stress and plastic viscosity were tested in a concrete truck. The measurements made with the truck were based on the ty...

PURPOSE The most common material for shielding is concrete, which can be made using various materials of different densities as aggregates. New techniques in radiotherapy, as IMRT and VMAT, require more monitor units and it is important to develop specifically designed shielding materials. METHODS Arraela S.L. has developed new concrete (CONTEK®-RFH2), which is made from an arid with a high p...