semiconducting carbon nanofibers (cnf) are prepared from three different sources, i.e., acetylene, ethanol, and cotton by the chemical vapor deposition (cvd) process. these fibers are having rich elastic, engineering and conductivity properties. fresh self-compacting concrete (scc) flows into place and around obstructions under its own weight to fill the formwork completely and self-compact, wi...

Characteristics of produced concrete become changedthrough changingthe characteristics of materials constituting the concrete. These changes include: The quality of cement, the real ration of water to cement: with neglecting the further water within the aggregates or lack of that, the consideredratio fluctuates and the characteristics of the aggregate which are related to the following dimensio...

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...

Elevated rail transit has been developed in some big cities in China in recent years. However, specialized codes for design of the bridges in the elevated rail transit system have not yet been established. Based on the prestressed concrete (PC) box girder bridges on Guangzhou metro line 4, some technical features of design principle and technology requisition, ensemble plan and design load of b...

background: high density concrete is extensively used for efficient radiation attenuation in radiotherapy rooms and nuclear reactors. over the past eight years, some efficient galena-based concrete samples for shielding x or gamma rays was produced. the goal of this study was to produce a novel high density concrete against neutron and photon radiations using tourmaline and galena. materials an...

The early age shrinkage is responsible for the early age cracking of concrete. It is very critical for durability of concrete. The change in volume of concrete due to evaporation of water or dehydration process is known as shrinkage. To reduce the early age shrinkage utilized the supplementary cementitious material (SCM) in concrete. In present research industrial and agricultural waste byprodu...

pervious concrete is a concrete mixture prepared from cement, aggregates, water, little or no fines, and in some cases admixtures. the hydrological property of pervious concrete is the primary reason for its reappearance in construction. much research has been conducted on plain concrete, but little attention has been paid to porous concrete, particularly to the analytical prediction modeling o...