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...

a comparison between design codes i.e. aci and aisc-lrfd in evaluation of flexural strength of concrete filled steel tubular columns (cfts) is examined. for this purpose an analytical study on the response of cfts under axial-flexural loading is carried using three-dimensional finite elements with elasto-plastic model for concrete with cracking and crushing capability and elastoplastic kinemati...

the strength of concrete is a function of the proportions of the constituent materials, namely, cement, water, fine and coarse aggregates. the conventional methods used to determine the mix proportions that will yield the desired strength, are laborious, time consuming and expensive. in this paper, a mathematical method based on modified regression theory is formulated for the prediction of con...

This paper describes an examination of the development of tension lap splices in high-strength concrete and the applicability of the restriction in the ACI 318 code where the values of √fc′ used to calculate development length shall not exceed 100 psi. The focus is on the development of splices with Grade 60 epoxy-coated and uncoated bars in normalweight concrete. A summary of the behavior of b...

Polymer modified concrete (PMC) consists of Portland cement concrete with a polymer modifier. Its advantages are proper bonding strength to substrate concrete, high tensile and flexural strength and low amount of shrinkage and permeability. Using PMC overlays can be considered as a method for preservation of damaged concrete structures due to their suitable performance and durability. In this r...

This paper summarizes the test results of an extensive research program sponsored by the US Transportation Research Board of the National Research Council to examine the behavior of high-strength concrete rectangular columns subjected to concentric and eccentric loading conditions. The variables considered in this investigation were concrete strength ranging from 7.9 ksi (55 MPa) to 16.5 ksi (1...

concrete is the most common material used to line irrigation canals and must maintain its durability for the lifetime of the canal. compressive strength has been used as an index to control the quality of concrete; concrete that remains durable under freeze-thaw conditions is that with high compressive strength. research has shown that concrete linings can show suitable compressive strength in ...

Recent scientific concerns to achieve sustainability in construction have suggested the implementation of using recycled aggregate in concrete because it has the potential to reduce the demand for extraction of natural raw materials and decrease the volume of wastes landfilled. In this respect, this study aims to investigate the suitability of using ceramic tile (CT) and ceramic sanitary (CS) w...

Recently, the use of high-strength concrete has become more popular due to the availability and significant variety of the admixtures. High-strength concrete increases the load carrying capacity of the columns, therefore, reduces their sizes in buildings and bridges. In bridges, high-strength concrete could result in reduction of number of girders as well as an increase in the span length which...