having observed the costly failures of different cutoff walls, that had been constructed according to the mix design specified by reputable consultants in iran, a research programme was conducted to study the effects of constituent materials on the properties of plastic concrete. the main properties, such as compressive strength, biaxial and triaxial strains, permeability, and modulus of elasti...

sandwich panels as composite materials have two external walls of either metallic or polymer type. the space between these walls is filled by hard foam or other materials and the thickness of different layers is based on the final application of the panel. in the present work, the extent of variation in core density of polyether urethane foam and subsequent flexural and compressive changes in s...

due to their widespread availability, sandstones are commonly used as a natural stone for buildings, monuments and sculptures. in thecurrent study, nine sandstone samples from the upper red formation (specified by the letters a, b, c, cg, s, s1, sh, tr and min)were studied from a petrophysical point of view and their durability was evaluated. then, their suitability as building stones wasassess...

A post-growth chemical vapor deposition (CVD) treatment was used to tune the compressive mechanical properties of carbon nanotube (CNT) arrays. Millimeter tall CNT arrays with low compressive resilience were changed to a foam-like material with high compressive strength and almost complete recovery upon unloading. The foam was tuned to provide a range of compressive properties for various appli...

This study experimentally investigates the effect of multi-walled carbon nanotubes (MWNT’s), as a reinforcing material, on the physical properties of heavy-weight oil well cements. A candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Carbon nanotubes (CNT’s) are added as fibers to the cement slurry and the i...

:the aim of this work is to investigate the influence of sodium oxide on properties of fresh and hardened paste of alkali-activated blast furnace slag from isfahan steel plant. the silica modulus (sio2/na2o) of activator was adjusted at 0.6 and a number of mixes were designed in such a way to contain different levels of sodium oxide including 1, 2, 3, 4, 5, and 6% by weight of dry slag. the mos...

with many years of construction and application of common concrete, researchers have always been searching for a better composition. one of the notable ideas for achieving such a composition is using recycled materials. one of the materials which is suitable for environment and constant development is damaged tires .for studying mechanical properties of concrete containing tire particles, a ser...

The aim of this work is to evaluate the influence of fabrication methods on the com-pressive properties of sandwich composites using both experimental work and numerical simulations. Two types of sandwich composites with E-glass/Kevlar/polyester resin facings and End-grain balsa wood as core have been produced by vacuum infusion processing (VIP) and hand-lay up (HL) method. Compression tests on...

The application of magnesium alloys is greatly limited because of their relatively low strength and ductility. An effective way to improve the mechanical properties of magnesium alloy is to refine the grains. As the race for better materials performance is never ending, attempts to develop viable techniques for microstructure refinement continue. Further refining of grain size requires, however...