Abstract
The Groundnut shell ash is generated from the incineration of groundnut shell which is an agricultural waste. In highway
construction, efforts are made to utilize waste materials to improve the strength and durability properties of bituminous
mixes rather than disposing in landfills or incinerating them. These efforts are carried out with the view to manage waste,
reduce the asphalt production cost, and reduce the detrimental environmental effects associated with the production of
cement. This study utilizes Groundnut shell ash (GSA) as a partial replacement of cement in hot mix asphalt (HMA)
production. The Physical properties of asphalt concrete constituent materials were tested in accordance with the standard
specifications and found to satisfy code requirements. The x-ray fluorescence conducted on the GSA show that it is a
pozzolana of class C. Several trial mixtures with bitumen content of 4.5, 5.0, 5.5, 6.0 and 6.5 % as specified by Overseas
Road Note 19 and Federal Ministry of Works and Housing were produced to obtain optimum bitumen content (OBC) of 5.5
%. GSA replacement of cement was investigated at 2, 4, 6, 8, 10 and 12 % using the Marshall mix method. From the
Marshall Stability-Flow test analysis, the sample prepared with 6 % GSA replacement at 5.5 % bitumen content satisfy the
Federal Ministry of Works and Housing specification requirements for use in wearing course of heavily trafficked roads.

Key words: Groundnut Shell Ash, Hot Mix Asphalt, Optimum Binder Content, Marshall Stability, Bitumen.