Modeling the effect of sulphate on strength development of paste backfill and binder mixture optimization

Abstract The increasing use of paste backfill in underground mining makes it necessary to quantify the effect of sulphate on the strength development and economical performance of paste backfill. Therefore, the main objective of this study was to develop a methodological approach and a mathematical model to analyze and predict the strength development and cost of underground paste backfill containing different amounts of sulphate. This study demonstrates that the paste backfill can be defined as a “mixture system”. We were able to show that a material model based on quadratic functions can be a suitable basis for the prediction of both the mechanical [uniaxial compressible strength (UCS)] and economic (binder cost) properties of paste backfill. The developed models allowed us to obtain valuable results about the relationship between the sulphate quantity and the mechanical performance of the backfill and the prediction of its strength at different curing times. This study has demonstrated that the sulphate significantly influences paste backfill strength. This influence is related to its concentration, the curing time and the amount and chemical composition of the cement.

[1]  Menashii D. Cohen,et al.  Magnesium sulfate attack on portland cement paste-I. Microstructural analysis , 1992 .

[2]  Kazuyuki Torii,et al.  Effects of fly ash and silica fume on the resistance of mortar to sulfuric acid and sulfate attack , 1994 .

[3]  R. Gillham,et al.  Pyrite oxidation in carbonate-buffered solution: 1. Experimental kinetics , 1988 .

[4]  H. Taylor,et al.  Microstructural and microanalytical studies of sulfate attack. I. Ordinary portland cement paste , 1992 .

[5]  Menashii D. Cohen,et al.  Theories of expansion in sulfoaluminate - type expansive cements: Schools of thought , 1983 .

[6]  Jacques Ouellet,et al.  Cementitious backfill with high sulfur content Physical, chemical, and mineralogical characterization , 1999 .

[7]  A microstructural study of the effect produced by magnesium sulfate on plain and silica fume-bearing Portland cement mortars , 1993 .

[8]  K. Scrivener,et al.  Mechanisms of chemical degradation of cement-based systems: proceedings of the Materials Research Society's Symposium on Mechanisms of Chemical Degradation of Cement-based Systems, Boston, USA, 27-30 November 1995 , 1997 .

[9]  Xu Zhongzi,et al.  The process of sulfate attack on cement mortars , 1996 .

[10]  D. D. Double,et al.  New developments in understanding the chemistry of cement hydration , 1983, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[11]  A. Donald,et al.  Pre-induction and induction hydration of tricalcium silicate: an environmental scanning electron microscopy study , 1995, Journal of Materials Science.

[12]  James G. Wang.  Sulfate attack on hardened cement paste , 1994 .

[13]  Jan Skalny,et al.  Materials science of concrete , 1989 .

[14]  B. Mather.  A discussion of the paper “theories of expansion in sulfoaluminate-type expansive cements: Schools of thought,” by M.D. Cohen , 1984 .

[15]  Tikou Belem,et al.  The effect of microstructural evolution on the physical properties of paste Backfill , 2001 .

[16]  R. J. Mitchell,et al.  Behaviour of cemented tailings sands , 1982 .

[17]  S. Chandra,et al.  10th International congress on the chemistry of cement , 1997 .

[18]  Edgardo F. Irassar,et al.  ETTRINGITE FORMATION IN LOW C3A PORTLAND CEMENT EXPOSED TO SODIUM SULFATE SOLUTION , 1997 .

[19]  F. Lea.  The chemistry of cement and concrete , 1970 .

[20]  Menashii D. Cohen,et al.  Magnesium sulfate attack on portland cement paste — II. Chemical and mineralogical analyses , 1992 .

[21]  Douglas C. Montgomery,et al.  Response Surface Methodology: Process and Product Optimization Using Designed Experiments , 1995 .

[22]  G. Box,et al.  On the Experimental Attainment of Optimum Conditions , 1951 .

[23]  Osb Al-Amoudi,et al.  EFFECT OF MAGNESIUM SULFATE AND SODIUM SULFATE ON THE DURABILITY PERFORMANCE OF PLAIN AND BLENDED CEMENTS , 1995 .

[24]  B. Mather.  Discussion of “The Process of Sulfate Attack on Cement Mortars” by Shen Yang, Xu Zhongzi, and Tang Mingshu , 1997 .

[25]  M. Benzaazoua,et al.  SULPHIDE REACTIVITY WITHIN CEMENTED PASTE BACKFILL: OXYGEN CONSUMPTION TEST RESULTS , 2003 .

[26]  J. Beaudoin,et al.  Mechanism of sulphate expansion II. Validation of Thermodynamic Theory , 1992 .

[27]  A. L. Anderson.  The incipient oxidation of galena , 1930 .

[28]  Menashii D. Cohen,et al.  Durability of Portland Cement-Silica Fume Pastes in Magnesium and Sodium Sulfate Solutions , 1988 .

[29]  Jan Olek,et al.  Mechanism of sulfate attack: A fresh look: Part 1: Summary of experimental results , 2002 .

[30]  J. F. Archibald,et al.  Ground waste glass as a pozzolanic consolidation agent for mine backfill , 1995 .

[31]  H. Taylor,et al.  Microstructural and microanalytical studies of sulfate attack. IV. Reactions of a slag cement paste with sodium and magnesium sulfate solutions , 1996 .

[32]  P. K. Mehta.  Mechanism of sulfate attack on portland cement concrete — Another look , 1983 .

[33]  Bing Tian,et al.  Does gypsum formation during sulfate attack on concrete lead to expansion , 2000 .

[34]  J. Olek,et al.  MECHANISM OF SULFATE ATTACK: A FRESH LOOK. PART 2: PROPOSED MECHANISMS , 2003 .

[35]  Tikou Belem,et al.  A contribution to understanding the hardening process of cemented pastefill , 2004 .

[36]  H. Taylor,et al.  Microstructural and microanalytical studies of sulfate attack III. Sulfate-resisting portland cement: Reactions with sodium and magnesium sulfate solutions , 1995 .

[37]  J. Herman,et al.  Pyrite oxidation at circumneutral pH , 1991 .

[38]  J. Beaudoin,et al.  Mechanism of sulphate expansion I. Thermodynamic principle of crystallization pressure , 1992 .

[39]  J. E. Bailey,et al.  On the hydration of Portland cement , 1978, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[40]  Ferri P. Hassani,et al.  Strength development in underground high-sulphate paste backfill operation , 2001 .

[41]  Tikou Belem,et al.  Chemical factors that influence the performance of mine sulphidic paste backfill , 2002 .