Gap-Graded Concrete for Paving Construction

Results of a laboratory investigation and a full-scale highway experiment on National Highway No.2 between Delhi and Agra with gap-graded concrete are reported. The findings indicate that good concrete mixes can be prepared with gap-graded coarse aggregate. Gap-graded concrete leads to about 5%-8% economy in the costs of pavement construction. The economy is enhanced to 8%-12%, when coarse sand conforming to the specification costs more than the fine sand and fine sand is blended with the coarse sand to the extent of 20%-50% of the total quantity of fine aggregate. Performance of the experimental gap-graded concrete pavement sections under heavy traffic over a period of 5 yr has been observed to be somewhat superior to that of the section using continuously graded concrete.