Stabilization of Laterite for Base Course Construction
No Thumbnail Available
Date
2017-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
The demand for different kinds of naturally occurring construction materials is
increasing in areas like the road construction industry. Unfortunately, not all the natural
materials along the vicinity of road projects are suitable for the proposed construction
because these materials fail to fulfill the standard quality requirements. One of these
materials are lateritic materials which often do not fulfill the plasticity index (PI);
California Bearing Ratio (CBR) and gradation requirements of many agencies for road
base material. Hence, this research was initiated with the motivation of upgrading and
utilizing the laterite material, which is one of the abundantly available substandard
materials in the Western part of Ethiopia.
In this research, the laterites, found along the Assosa – Kurmuk road, were sampled
and stabilized so that they can be used for the construction of the base layer of all
standard roads. The stabilization was done using lime and cement as two alternative
stabilizers. Moreover, cost comparison were also carried out to assess the cost benefit
of using stabilized laterite road base in lieu of the crushed stone road base in such
areas where laterites are available in surplus quantity.
Accordingly, it was found that both lime and cement stabilized laterites can be used for
road base construction. In both the lime and cement stabilization cases, the optimum
binder content to meet the Joint US Army and Air Force (1994) strength and durability
requirements is 10% by weight of the host material. However, the optimum binder
contents to satisfy the requirements of ERA Standard Technical Specification (2013)
are 4% and 6% for both lime and cement stabilized laterites, both percent by weight of
the host material. The cost comparison, on the other hand, indicated that based on the
current market price during the study period, only the cement stabilized laterite has
cost benefit against using the crushed aggregates for the road base construction.
Key words: laterite, cement-stabilization, lime-stabilization, base course, marginal
quality materials
Description
Keywords
laterite; cement-stabilization; lime-stabilization; base course; marginal quality materials