The chloride corrosion of reinforcing steel in reinforced concrete (RC) structures is a significant reason for premature deterioration and failure of RC structures in aggressive environments such as Persian Gulf region. This is one of the most important sources of engineering and economic problems in developed countries. So, the repair and maintenance of RC structures exposed to corrosive envir...

background: in megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. the use of high-density concrete decreases the required thickness of the concrete barrier hence, its disadvantage is its high cost. in a nuclear reactor, neutron radiation is the most difficult to shield. a method for p...

background: radon, thoron and their progenies are the most important contributions to human exposure from natural sources. radon exists in soil gas, building materials, indoor atmosphere etc. among all the natural sources of radiation dose to human beings, inhalation of radon contributes a lot. the work presented here emphasizes the long term measurements of radon, thoron and their progeny conc...

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...

___________________________________________ In “Why is There Anything at All?” Peter van Inwagen argues that even though it was never necessary that concrete beings existed, it was always maximally probable – just short of necessity – that they did (van Inwagen, 1996). I argue that van Inwagen’s argument fails, albeit for an interesting reason which has remained so far unnoticed in the literatu...

    Freezing and thawing resulting from the ingression of water into concrete causes cracking or spalling. Corrosive ions such as chloride or sulfate penetrate the concrete surface and eventually reach the reinforcing steel. This causes the steel to corrode.     Because of the high maintenance and replacement costs, responsible officials should be increasingly concerned about the growing number...

research on the heavy concrete technology expanded rapidly in the last decades. this kind of the concrete can be used for different purposes such as the protective shields of the medical centers and nuclear power plants. ilmenite, limonite, hematite, magnetite and barite are the common mineral aggregates which are used in the heavy concrete construction technology. in this research the mechanic...

Attack and disintegration of concrete structures under the influence of aggressive fluids, wet gases, etc. are understood as corrosion of concrete. The corrosion of concrete is a chemical, colloidchemical process, yet often a physico-chemical one, while that of reinforced concrete supported oil platforms are subjected to marine environment in the Persian Gulf and therefore corroded. In the pres...

one important application of fiber reinforced polymer (frp) is to confine concrete as frp jackets in seismic retrofit process of reinforced concrete structures. confinement can improve concrete properties such as compressive strength and ultimate axial strain. for the safe and economic design of frp jackets, the stress-strain behavior of frp-confined concrete under monotonic and cyclic compress...