169) The recommended grade of tar for grouting purpose is

170) Softening point of bitumen to be used for read construction at a place where maximum temperature is 40° C should be

171) For rapid curing cutbacks, the oil used is

172) The method of design of flexible pavement as recommended by IRC is

173) The group index for a soil, whose liquid limit is 40 percent, plasticity index is 10 percent and percentage passing 75 micron IS sieve is 35, is