Silica fume has been largely used in concrete in recent decades due to its effect on improvement of strength and durability of concrete. On the other hand, attention has been recently paid to the use of limestone powder as a substitute for part of cement in concrete, basically because of its low price and its positive effect on the durability of concrete. The aim of the current study is the i...

As regards if curing stops for some time and then resumes again, then strength gain will also stop and reactive, in this study with choose suitable curing conditions after improper first curing (recurring) for normal and silica-fume concrete, Effect of this curing conditions on strength and permeability was investigated. The results from tests such as compressive strength, capillary water absor...

this study is concerned with the synthesizing of cu-zn nano-ferrite particles in the laboratory applying simple techniques. the morphology of the synthesized nano-particles was analyzed using transmission electron microscopy (tem), and the minerals were identified using x-ray diffraction (xrd). the nano material was used to replace 1- 4 percent by weight of portland cement in cement pastes and ...

the effects of adding nano-silica particles on the compressive strength and water permeability of concrete and its comparison with that of micro-silica were investigated in this work. the effect of combination of nano- silica and micro-silica were also studied in this work, which resulted in an increase in compressive strength of concrete in comparison with other concrete specimens tested in th...

in this paper, after collecting the rock samples from eight mines and one high way slope, the tests for determination of dry density, uniaxial compressive strength, tensile strength (brazilian test), elastic modulus, schmidt hammer rebound number have been done on samples. in addition, in order to calculating the mean size of rock grains, quartz content, hardness and abrasivity, a thin sections...

an application of aerated concret (foam concrete) was experimentally studied. in this study the compressive strength of the proposed concrete was measured the effect of parameters such as aggregate size of broken stone, quantity of cement and various densities were exprementally studies, and the best mixture was select.these prepared mixtures are practically useful to optimize the consumption o...

Surface wave velocity measurement of concrete using ultrasonic sensors requires testing on only one side of a member. Thus, it is applicable to concrete cast inside a form and is often used to detect flaws and evaluate the compressive strength of hardened concrete. Predicting the in situ concrete strength at a very early stage inside the form helps with determining the appropriate form removal ...

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...

Lightweight yet stiff and strong lattice structures are attractive for various engineering applications, such as cores of sandwich shells and components designed for impact mitigation. Recent breakthroughs in manufacturing enable efficient fabrication of hierarchically architected microlattices, with dimensional control spanning seven orders of magnitude in length scale. These materials have th...