The Influence of Carbonation on the Behaviour of Cement-based Materials Used in Contaminated Land Treatment

This paper details results of a preliminary investigation into the influence of initial heating followed by carbonation for accelerating the ageing of four cement-based grout mixtures used to treat contaminated soils. The four cement-based grouts differed in composition in relation to the binders in use. One of the grouts contained ash, the second ash and lime, and the third bentonite. The contaminants used comprised of compounds of five heavy metals (Pb, Cu, Cd, Ni and Zn) and paraffin oil. Samples were cured adopting an initial exposure period to elevated temperature followed by different durations of exposure to carbon dioxide (accelerated carbonation). Tests were conducted for strength, carbonated depth, leachate pH and leaching after 28 and 90 days of curing, with the control samples additionally tested after 180 days. The results suggested that the four grouts behaved differently under the exposure curing conditions. The initial exposure to elevated temperature generally had improved strength and leaching results and the exposure to different durations of carbon dioxide had an influence on the behaviour of the grouts with the longer durations of exposure generally yielding better results.

• INTRODUCTION

• MATERIALS

• PROCEDURE

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES