New method for estimating unconfined compressive strength (UCS) using small rock samples

Sheshde, E. Ahmadi; Cheshomi, Akbar

doi:10.1016/j.petrol.2015.06.022

Cited by 21 publications

(3 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, different fixtures have been proposed for singleparticle point load tests. Blunt cylindrical indenters or large parallel platens have been used for estimating the tensile strength of regular-shaped (spheres [16,17], cubes and prisms [15]) as well as irregularly-shaped particles [18][19][20].The types of fracture for regularlyshaped particles were similar to those expected using the point load test method. While testing irregularlyshaped particles has the benefit of convenience, it is responsible for generating large scatter in the data [7,20], since optimal loading conditions cannot be ensured.…”

Section: Introductionmentioning

confidence: 99%

“…PLT has the advantage of using universal testing machines, that are commonly found in civil engineering laboratories. Tests were used to qualify particles of many rock types (gneiss, granites, quartzite, diorite, basalt, limestone, marble) for geotechnical applications [15][16][17], railway ballast [18,19], or coarse aggregates used in concrete [20]. Tensile strengths of the rock particles (from 4 to 30 mm of size) are significantly variable, varying from about 3 to 9 times even for a material with the same mineralogical origin.…”

Section: Introductionmentioning

confidence: 99%

“…Different approaches have been used to conduct the test: some researchers prefer to work with force control systems [6,8,9], while others favor displacement control [10][11][12][13][14][15], without a consensus on which condition is preferable. In American Standard ASTM D 4179, the control is done by force rate (4.40-44.00 N/s) whereas in Japanese's standard JIS Z 8841; the control is done by displacement rate (0.15-0.30 mm/s).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Improved method to measure the strength and elastic modulus of single aggregate particles

et al. 2019

View full text Add to dashboard Cite

The standard methods used to determine the mechanical properties of single aggregate particles have shortcomings. Indeed, methods that are commonly used to measure the strength of irregular particles do not provide their elastic modulus and are also only semi-quantitative. The aim of this work is to determine more accurately both the tensile strength and the elastic modulus of single coarse aggregate particles using the point load test fitted with tungsten carbide semi-spheres and coupled with a linear transducer. In the experiment, the poles of the particles are made flat and parallel at the points of contact with the semi-spheres of the apparatus, allowing to estimate the elastic modulus of aggregates in accordance to Hertz contact theory. Glass particles of different shapes (spheres, cubes, and prisms) were used as reference material to validate the experimental method and establish the optimal conditions to conduct the test. These conditions consisted of a deformation rate of 0.2 mm/min, a blunt 4.0-mm diameter cylinder piston for spherical particles, while two 14.0-mm diameter semi-spheres in the case of rectangular particles (cubes/prisms). It is also hereby proposed to measure the tensile strength of irregularly-shaped particles by a modified version of Hiramatsu and Oka's formula using the equivalent core diameter. The proposed method was then applied to measure the strength and modulus of coarse granite aggregate particles (25.0 to 9.5 mm). It demonstrated that the variability of the elastic modulus and tensile strengths of the individual aggregate particles was quite significant, confirming the importance of using the proposed improved method to qualify materials for structural (high strength) concrete, or to simulate/predict the mechanical behavior of concrete. Keywords Aggregates Á Single particle Á Elastic modulus Á Hertz contact theory Á Tensile strength Á Point load test This article was published with an erroneous name of one of the authors and therefore has been corrected.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved method to measure the strength and elastic modulus of single aggregate particles

et al. 2019

View full text Add to dashboard Cite

show abstract

Comparative Study Between Mathematical Models for Prediction of Strength Properties of Rocks in United Arab Emirates

Omar

2018

Sustainable Civil Infrastructures

View full text Add to dashboard Cite

Tensile strength of large-scale incipient rock joints: a laboratory investigation

et al. 2017

View full text Add to dashboard Cite

In this paper, a testing methodology was developed in the laboratory to measure the tensile strength of large-scale incipient rock joints. In the test, an expansive grout was used to develop the tensile force. Each test comprises two phases: Phase i test and Phase ii test. The Phase i test identified sample failure time, while the Phase ii test measured the corresponding tensile force arising from the expansive grout. Ostensibly homogeneous rock samples without incipient joints were firstly tested to establish the methodology. Tensile strength of block samples containing incipient rock joints was then measured using the established testing scheme. The test results have been compared with those obtained from conventional Brazilian and uniaxial tension tests as suggested by ISRM. The proposed approach is capable of giving a measure of tensile strength of large-scale incipient rock joints, although somewhat smaller strength than that from the standard approaches was occasionally measured in the preliminary tests on ostensibly homogeneous samples. Effects of stress concentration, sample scale, loading rate and expansive tensile force on the testing results were discussed. Furthermore, this simple and practical testing scheme is proposed for the measurement of the in situ tensile strength of rock and incipient discontinuities in the field, which if successful will provide a more scientific guidance on the rock mass classification and engineering design.

show abstract

New method for estimating unconfined compressive strength (UCS) using small rock samples

Cited by 21 publications

References 23 publications

Improved method to measure the strength and elastic modulus of single aggregate particles

Improved method to measure the strength and elastic modulus of single aggregate particles

Comparative Study Between Mathematical Models for Prediction of Strength Properties of Rocks in United Arab Emirates

Tensile strength of large-scale incipient rock joints: a laboratory investigation

Contact Info

Product

Resources

About