When exploiting the deep resources, the surrounding rock readily undergoes the hole shrinkage, borehole collapse, and loss of circulation under high temperature and high pressure. A series of experiments were conducted to discuss the compressional wave velocity, triaxial strength, and permeability of granite cored from 3500 meters borehole under high temperature and three-dimensional stress. In...

Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a crack sandwiched between two compressive layers suggests that the threshold st...

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...

Triaxial consolidated drained, unconfined compression, and CBR tests have been conducted in order to study the stress-strain, strength, and volume change characteristics of fine sand specimens reinforced by polymeric fibers made from carpet wastes. The variables are aspect ratio (length/width) and weight percentage of the fibers. The results indicate that the peak strength and total volume chan...

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...

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...

Silica fume has been largely used in concrete in recent decades due to its effect on improvement of strength and &#10durability 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...

Understanding of the compressive strength of concrete is important for activities like construction arrangement, prestressing operations, and proportioning new mixtures and for the quality assurance. Regression techniques are most widely used for prediction tasks where relationship between the independent variables and dependent (prediction) variable is identified. The accuracy of the regressio...