An Assessment of the Quality of Hot Mix Asphaltic Concrete along Abuja–Lokoja Highway

Abstract

Rutting failure in hot mix asphaltic concrete has become a menace bedeviling
both newly constructed and old road pavements in Nigeria. At the final stage
of rehabilitation and expansion of 170 kilometers Abuja–Lokoja dual
carriageway highway, the road is already showing features of rutting at
several portions. This paper investigates the causes of rutting usually
experienced on the Abuja-Lokoja road that results in vehicle accidents and
damages. Samples of asphaltic concrete were randomly cored at the rutted
and normal sections of the road. Each sample was analyzed in the laboratory
using the Nigerian and ASTM standards. The result indicated that the coarse
aggregate ratio and the fine aggregate coarse ratio of the cored samples tested
ranged between 0.33 - 0.49 and 0.54 - 0.64 as against Bailey’s
recommendation of 0.6 – 1 and 0.35 - 0.5 respectively. The excess fine
aggregate in the asphaltic concrete was discovered to have distorted the
aggregate interlocking required to resist the shearing load on the road when
vehicles navigate through it. Therefore, the excess fine aggregate is suspected
to be the cause of the rut failure on the road.