II. PAVEMENT ENGINEERING AND PAVING MATERIALS

3. RIGID PAVEMENTS

A. COMPLETED PROJECTS
1. Evaluation of Wollastonite in Concrete Works
Duration

May 2003 to March 2005
(i) Central Road Research Institute, New Delhi (R,I)
(ii) Wolkem India Limited, Udaipur (S)

 
Present Status and Progress
Project completed and final report submitted to the sponsor in March-2005.
 
Conclusions
Partial substitution of sand by natural Wollastonite micro fibres in normal and fly-ash concrete brings about 20 and 30 per cent improvement in compressive strength at 28 and 56 days respectively and 30 and 40 per cent increase in flexural strength for the same period. A comparison of the results revealed reduction in water absorption, drying-shrinkage and abrasion loss of concrete by incorporation of Wollastonite. Enhancement in durability against alternate freezing-thawing and sulphate attack was observed. An overall economy of 10 to 15 per cent in the construction cost of concrete pavement can be achieved by the incorporation of Wollastonite.
 
Significance
The results obtained from the study will open a new era for further R&D on the use of natural mineral fibres in concrete.
 
Recommendations
Construction of test sections with concrete incorporating Wollastonite should be done to evaluate the material in actual field conditions.