in this study, the effect of cement content on concrete performance in corrosive environments is investigated on concrete mixtures having the same water/cement (w/c) ratio. three w/c ratios (0.40, 0.45 and 0.50) were used and for each w/c ratio three mixtures were prepared with cement contents 350, 400 and 450 kg/m3. the compressive strength, electrical resistivity and chloride diffusivity of t...

in this study, the effect of cement content on concrete performance in corrosive environments is investigated on concrete mixtures having the same water/cement (w/c) ratio. three w/c ratios (0.40, 0.45 and 0.50) were used and for each w/c ratio three mixtures were prepared with cement contents 350, 400 and 450 kg/m3. the compressive strength, electrical resistivity and chloride diffusivity of t...

this paper is based on an experimental research that examined the effects of concrete`s major parameters on durability of concrete pavements and curbs under freezing and thawing cycles. these parameters include concrete mix design parameters such as water-cement ratio, fine aggregate percentage and using air entraining admixture and simulating real freeze-thaw cycles that infrastructures underg...

In cement-based materials porosity plays an important role in determining their mechanical and transport properties. This paper describes an improved low–cost embeddable miniature NMR sensor capable of non-destructively measuring evaporable water loss and porosity refinement in low and high water-to-cement ratio cement-based materials. The sensor consists of two NdFeB magnets having their North...

Many parameters are influenced by the diffusion of chloride on concrete in marine environments and these can affect concrete quality. In this study, the effect of water to cement ratio of 0.35, 0.40 and 0.45 on corrosion resistance and compressive strength of reinforced concrete was evaluated. Moreover, different percentages of micro silica (SiO2) including 5, 7.5 and 10% were utilized, in orde...

This paper presents the compressibility of tropical peat reinforced with cylindrical cement columns. When a cement column is installed vertically in peat, its compressibility is reduced because of the hardened skeleton matrix formed by cement particles bonding with adjacent soil particles in the presence of pore water. The effects of the cement column diameter on the compressibility have been i...

Water uptake in two glass-ionomer cements stored in various aqueous ionic solutions has been studied following a 6-week storage period, and the bound/unbound water ratio has been determined. Both types of cement took up water with net uptake varying with the storage solution. Uptake was greatest with KCl and lowest for 0.9 % NaCl. By comparison with an immature (1 hour old) specimen of each cem...

Exposure conditions significantly affect the resistance of cement to sulfate attack. This article investigates the effect of sulfate on electrical conductivity of ordinary Portland cement (OPC). Cement paste specimens were prepared according to water/cement (W/C) ratio equal 0.25 either free of sodium sulfate or its addition with concentrations of 5000ppm, 10000ppm and 15000ppm by weight. This ...

In studies conducted to determine the workability of concrete, the bagasse ash and rice husk ash were added as a partial replacement for cement. Trial mixes with the varying water cement ratio, replacement percentage, quantity of super plasticizer and viscosity modifying agent, were prepared and tested. The results were used as the basis for defining three optimum cement replacement mix proport...

H nuclear magnetic resonance (NMR), supported by a measurement of the degree of hydration using X-ray diffraction, has been used to fully characterise the nano-scale porosity and composition of calcium-silicate-hydrate (C-S-H), the active component of cement. The resultant “solid” density and composition are 3 g/cm 68 . 2 = ρ ; (Ca)1.53. (Si0.96,Al0.04)O3.51.(H2O)1.92 for an underwater cured, n...