scholarly journals Particle Size Distribution Effects on the Strength Characteristic of Cemented Paste Backfill

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 322 ◽  
Author(s):  
Jiangyu Wu ◽  
Meimei Feng ◽  
Zhanqing Chen ◽  
Xianbiao Mao ◽  
Guansheng Han ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Strength Characteristic ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Peak Strength ◽  
Strength Parameter ◽  
Cemented Paste Backfill ◽  
Paste Backfill

It is of great significance, for economic, environmental and security reasons, to investigate the strength characteristic of underground cemented paste backfill (CPB). Consequently, an ultrasonic test, uniaxial and triaxial compression experiment, and acoustic emission (AE) monitoring were carried out on CPB, for which the particles satisfied Talbot gradation. The homogeneity of CPB specimens was evaluated by ultrasonic pulse velocity (UPV). The stress–strain behavior and AE characteristic of CPB specimens under different Talbot indices and confining pressures were investigated. The effects of the particle size distribution and the confining pressure on the peak strength of CPB were analyzed. The strength parameter model of CPB under the coupled influence of the particle size distribution and the confining pressure was constructed based on the Mohr–Coulomb strength criterion. The results show that the peak strength of CPB is positively linear with confining pressure, however, the relationship between its strength parameters and the Talbot index can be characterized by a quadratic polynomial function. This suggests that there is an optimal gradation of particles reflected in the maximum strength of CPB.

scholarly journals Study on Microstructural Evolution and Strength Growth and Fracture Mechanism of Cemented Paste Backfill

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Jian-Xin Fu ◽  
Wei-Dong Song ◽  
Yu-Ye Tan
Keyword(s):  
Residual Strength ◽  
Mass Fraction ◽  
Solid Phase ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Cemented Paste Backfill ◽  
X Ray Diffraction ◽  
Pressure Peak ◽  
Paste Backfill ◽  
Curing Age

The relations among the uniaxial compressive strength of cemented paste backfill (CPB) with solid phase mass fraction, cement sand ratio, and curing age were studied. The UCS of CPB samples increased exponentially with the increase of solid phase mass fraction and curing age but increased linearly with the increase of cement sand ratio. The results of X-ray diffraction (XRD) and scanning electron microscope (SEM) showed that the strength was determined by the amount of ettringite and C-S-H gelling. With the increase of ettringite and C-S-H gelling, the strength became larger. The triaxial compression test was conducted by selecting four kinds of CPB samples. The results showed that, with the increase of confining pressure, peak and residual strength became larger, but the elastic modulus decreased. When the ratio of confining pressure and uniaxial strength is about 1 : 2, the CPB samples show significant ductility characteristics and the ratio of residual strength and peak strength increased obviously.

scholarly journals Particle Size Distribution of Cemented Rockfill Effects on Strata Stability in Filling Mining

Minerals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 407 ◽  
Author(s):  
Jiangyu Wu ◽  
Meimei Feng ◽  
Jingmin Xu ◽  
Peitao Qiu ◽  
Yiming Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Rock Mass ◽  
Particle Size Distribution ◽  
Coal Seam ◽  
Size Distribution ◽  
Longwall Mining ◽  
Poisson Ratio ◽  
Triaxial Compression ◽  
Friction Angle ◽  
Economic Benefits

It is of great significance for engineering safety, economic benefits, environmental protection, and sustainable development to investigate the strata stability in filling mining with cemented rockfill. Consequently, this paper is based on a specific coal mine where we applied the fully-mechanized longwall mining and filling and designed a cemented rockfill material for which the particles satisfied the Talbot gradation. Uniaxial and triaxial compression experiments were carried out on the cemented rockfill specimen, which obtained the relations between the mechanical parameters (Poisson ratio, elastic modulus, compressive strength, cohesive force, internal friction angle, and tensile strength) and the particle size distribution of the aggregate. The excavation and filling processes in the coal seam were simulated based on the numerical software FLAC3D. The characteristics of the displacement and stress fields of the strata when the goaf was filled by cemented rockfill with different granule gradations were discussed. The influences of the particle size distribution and mining distance on the maximum subsidence displacement of the coal seam roof, internal stress of the backfill, and the stress of the rock mass in the coalface were analyzed. The feasibility and effectiveness of the filling mining with cemented rockfill to protect the integrity of the overlying strata were discussed. The results showed that optimizing the particle size distribution of the aggregate in cemented rockfill could increase the loading capacity of the backfill to improve the filling effect, effectively control the strata movement, and decrease the stress of rock mass in the coalface to reduce the potential danger.

Effects of Particle Size Distribution on Corrosion Rate of Carbon Steel in Soil

2020 ◽  
Vol 69 (4) ◽  
pp. 102-106
Author(s):  
Shota Ohki ◽  
Shingo Mineta ◽  
Mamoru Mizunuma ◽  
Soichi Oka ◽  
Masayuki Tsuda
Keyword(s):  
Particle Size ◽  
Carbon Steel ◽  
Corrosion Rate ◽  
Particle Size Distribution ◽  
Size Distribution

DENSE SPRAY CORRECTIONS FOR DIFFRACTION-BASED PARTICLE SIZE DISTRIBUTION MEASUREMENTS

1995 ◽  
Vol 5 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Christine M. Woodall ◽  
James E. Peters ◽  
Richard O. Buckius
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution
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