EFFECT OF HEAT TREATMENT ON THE BEHAVIOUR OF MONTMORILLONITE CLAY IN THE PRESENCE OF LIME

The activation of clays by heat treatment will produce artificial pozzolana which reacts with Ca⁺² or Ca(OH)₂ in presence of water to form new building materials. In this study the montmorillonite clay was activated by burning at different temperatures (550,700,800,900 & 1000°C) then mixed with lime at different compositions. The dry mixtures were mixed with water at w/c ratios of 0.5,0.6 & 0.7 by weight. The resulting masses was then molded and the produced specimens were cured in an autoclave at 10 atmosphere pressure for different periods. The change occurring in the physico-chemical properties were investigated by compressive strength and chemically-combined water measurements, also the change in morphology and microstructure of hardened pastes were investigated using SEM tests. The results of this study indicate that the optimum activation temperature for montmorillonite clay to produce artificial pozzolana is 1000°C and the optimum mix composition with lime to produce binding compounds is 80% burnt mintmorillonite clay : 20% lime Ca(OH)₂.

• INTRODUCTION

• EXPERIMENTAL WORK

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES