concrete is one of the most important construction materials widely using in hydraulic structures, such as lining of irrigation canals. concrete durability might be decreased due to the environmental or inner factors with physical, chemical or mechanical reactions. since, the climatologically condition is variable in most part of the country, local studies are needed to evaluate of the weakness...

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...

concrete has a special place at the current century; it has been and is the most widely used building material. producing concrete has several environmental impacts that should be considered to prevent consequent problems. in recent years, several methods have been developed to produce concrete that is compatible with the environment and sustainable development basis. in these concretes, beside...

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...

The use of concrete in civil infrastructure is highly demanded structural and nonstructural elements. However, the high production could lead to severe pollution world. This can be decreased using sustainable materials mixed with cement obtain concrete. These include reinforcing fibers (e.g., steel, polypropylene, carbon fibers), recycled tire rubber, crushed glass, plastic, industrial waste) a...

In this study, first by surveythe parameters affecting the compressive strength, such as water to cement ratio, cementgrade, silica fume to cement percentage, and the various ratios oflight weight aggregate LECA, to total aggregate, Taguchi method is used, to test 9 mix designsobtained the mix design optimization. Since lightweight concrete is brittle like normal concrete, to resolve this probl...

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...

background: a major issue in many gene expressionstudies utilizing small amount of biological materials is thelimited quantity of rnapurified from clinical samples, which isoften used for rt-pcr or standard northern blot analysis.objectives: the smart cdna synthesis method and subsequentsmart-cdna-pcr technique was used to analyse 3genes in macroschizonts of theileria annulata in small lymphnod...

In the present study, a new method for retrofitting reinforced concrete beam is introduced in which steel-concrete composite jackets containing steel fiber is used. For this purpose, 75% of the peripheral surface of reinforced concrete beams was initially reinforced using steel plates and bolts, and steel fiber reinforced concrete was used between the steel plates and the peripheral surfaces of...

hot or cold weather condition affects the quality of the concrete in different ways, which one of them is increase or decrease in the initial temperature of the concrete. in this study, the impact of the initial temperature of the concrete on its quality in concrete kerbs made by dry pressing method with portland cement is examined. concretes with similar mix designs and initial temperatures of...