Analysis on the influence factor of low-strength wet shotcrete in frigid mining area

• Autorzy: Sun Wei , Shengyou Zhang , Feng Xinglong , Hou Kepeng

Identyfikatory

DOI

10.24425/ams.2020.133193

• Języki publikacji: EN

Abstrakty

EN

Wet shotcrete technology is being gradually used in roadway support in frigid mining areas. Thus, problems such as low strength, fragility, and high repair rate have also emerged. This study focuses on low strength, cracking, and other problems in the wet shotcrete support of a mine. It introduced the fishbone diagram to investigate the effects of temperature, cement content, and water-cement ratio (W/C) on the strength of the shotcrete layer. The microscopic morphology of wet shotcrete based on scanning electron microscopy (SEM) is observed. Results demonstrated that temperature was the main influencing factor of wet shotcrete in frigid mining areas. When the curing temperature was lower than 10°C, the early strength of wet shotcrete dropped significantly. Temperatures above 15°C were favorable for later gain in strength. W/C was of a complementary relationship with strength development at different ages. Temperature was the essential factor that influenced the microscopic morphology of wet shotcrete. Furthermore, internal initial porosity and aggregate interface bonding strength had a direct effect on macro-mechanical properties of wet shotcrete.

Słowa kluczowe

EN

wet shotcrete; frigid area; Fishbone Diagram; temperature; low strength

PL

temperatura; beton natryskowy; obszar górniczy; kopalnia

• Wydawca: Instytut Mechaniki Górotworu PAN
• Czasopismo: Archives of Mining Sciences
• Rocznik: 2020
• Tom: Vol. 65, no. 2
• Strony: 285--298
• Opis fizyczny: Bibliogr. 27 poz., rys., tab., wykr.

Twórcy

autor

Sun Wei

• Kunming University of Science and Technology, Faculty of Land Resources Engineering, Kunming 650093, China
• Yunnan Key Laboratory of Sino-German Blue Mining and Utilization of Special Underground Space, Kunming 650093, China

autor

Shengyou Zhang

• Kunming University of Science and Technology, Faculty of Land Resources Engineering, Kunming 650093, China
• Yunnan Key Laboratory of Sino-German Blue Mining and Utilization of Special Underground Space, Kunming 650093, China

autor

Feng Xinglong

• Yunnan Diqing Non-Ferrous Metals Industry Co., Ltd, Diqing 674400, China

autor

Hou Kepeng

• Kunming University of Science and Technology, Faculty of Land Resources Engineering, Kunming 650093, China
• Yunnan Key Laboratory of Sino-German Blue Mining and Utilization of Special Underground Space, Kunming 650093, China

Bibliografia

• [1] Alexander K.M., Wardlaw J., Gilbert D.J., 1968. Aggregate cement bond cement paste strength and the strength of concrete. in The Structure of Concrete, edited by A.E. Brooks and K. Newman (Cement and Concrete Association, London), pp. 58-81.
• [2] Bonnel D.G.R., Harper F.C., 1950. Thermal cxpansion of concrete. I. Civil Eng. 4, 320-330.
• [3] Chan D.W.M., Kumaraswamy M.M., 2002. Compressing construction durations: lessons learned from Hong Kong building projects. Int. J. Proj. Manage 20, 23-35.
• [4] Chang C.S., Yin Z.Y., 2009. Micromechanical Modeling for Inherent Anisotropy in Granular Materials. J. Eng. Mech. 7, 830-839.
• [5] Chen J.X., Deng X.H., Luo Y.B., He L.C., Liu Q., Qiao X., 2015.Investigation of microstructural damage in shotcrete under a freeze-thaw environment. Constr. Build. Mater. 83, 275-282.
• [6] Chen J.X., Zhao X.Z., Luo Y.B., Deng X.H., Liu Q., 2014. Investigating freeze-proof durability of C25 shotcrete. Constr. Build. Mater. 61, 33-40.
• [7] Fall M., Samb S.S., 2009. Effect of high temperature on strength and microstructural properties of cemented paste backfill. Fire Saf. J. 44, 642-651.
• [8] Han B., Wang X.L., Wen Y.D., 2010. Drift support technology with wet shotcrete method in weak rock mass.J. Cent. South Univ. 41, 2381-2385.
• [9] Huang J., Wu S.X., Shen D.J., 2010. Experimental Study on Thermal Expansion Coefficient of Different Type Coarse Aggregates Concrete at Early Ages. Struct. Eng. 3, 154-158.
• [10] Husem M., Gozutok S., 2005. The effects of low temperature curing on the compressive strength of ordinary and high performance concrete. Constr. Build. Mater. 19, 49-53.
• [11] Jiang C.H., Yang Y., Li P., Wang X.D., 2013.Time Dependence on Thermal Expansion Behavior of Cement Mortar at Early Ages. J. Chin. Ceram. Soc. 5, 605-611.
• [12] Li S.S., Lee L.C., 2011. Using fishbone analysis to improve the quality of proposals for science and technology programs. Res. Eval. 20, 275-282.
• [13] Malmgren L., Nordlund E., Rolund S., 2005. Adhesion strength and shrinkage of shotcrete. Tunn. Undergr. Sp. Tech. 20, 33-48.
• [14] Pokharel M., Fall M., 2013.Combined influence of sulphate and temperature on the saturated hydraulic conductivity of hardened cemented paste backfill. Cem. Concr. Compos. 38, 21-28.
• [15] Qiao Y., Wang H.F., Cai L.C., Zhang W., Yang B.H., 2016. Influence of low temperature on dynamic behavior of concrete.Constr. Build. Mater. 115, 214-220.
• [16] Qian C.X., Zhu C.F., 2009. Influence of Aggregate Size on Thermal Expansion Property of Concrete.J. Chin. Ceram. Soc. 1, 18-22.
• [17] Rispin M., Runciman N., Knight B., 1999. Shotcrete research and development at INCO’s test mine. Proceedings, 3rd International Symposium on Sprayed Concrete: Modern Use. Oslo, Norway.
• [18] Thomas E.G., 1969. Characteristics and Behaviour of hydraulic fill material. University of Queensland, Australia, 33-45.
• [19] Wang J.B., Niu D.T., Zhang Y.L., 2015. Mechanical properties, permeability and durability of accelerated shotcrete. Constr. Build. Mater. 95, 312-328.
• [20] Wang J.B., Niu D.T., 2016. Influence of freeze-thaw cycles and sulfate corrosion resistance on shotcrete with and without steel fiber. Constr. Build. Mater. 122, 628-636.
• [21] Wang S.Y., Wu A.X., Han B., 2013. Mechanical model of wet shotcrete + resin bolt coupling support. J. Cent. South Univ. 44, 3486-3492.
• [22] Yang A.J., Zhou D.M., 2004. Tunnel wet concrete shot technology in permafrost region. China Railw. Sci. 25 ,141-144.
• [23] Yao S., Han B., Wu A.X., Wang Y.M., 2015. Mix Optimization of Mechanized Wet Shotcrete in High-stress Fractured Nickel Mine. Metal Mine 11, 27-32.
• [24] Yun K.K., Choi P., Yeon J.H., 2015.Correlating rheological properties to the pumpability and shootability of wet-mix shotcrete mixtures. Constr. Build. Mater. 98, 884-891.
• [25] Yun K.K., Choi S.Y., Yeon J.H., 2015. Effects of admixtures on the rheological properties of high-performance wet-mix shotcrete mixtures. Constr. Build. Mater. 78, 194-202.
• [26] Zhang Z.M., Zhou H.J., Zhao J.K., 2004. Influences of temperature on strength of concrete. J. Hohai Univ. (Nat. Sci) 6, 674-679.
• [27] Zhao G.Y., Ma J., Kang P., 2013. Mix ratio optimization of alpine mine backfill based on the response surface method. J. Univ. Sci. Technol. B. 35, 559-565.

Uwagi

PL

Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2020)