Laboratory Analysis of Some Index Properties of Lateritic Soil Partially Replaced with Quarry Dust

Abstract

The index properties of soils are properties which facilitate the
identification and classification of soils for engineering purposes.
These properties indicate the type and conditions of the soil. Over the
years, it has been observed that failure of infrastructure occurs when
poor earth materials are used in construction and lateritic soil is one
of these earth materials. They lack the capacity to perform
satisfactorily in the landfill areas because of their high hydraulic
conductivity despite the fact that they are firm soils. The materials
used for this research are lateritic soil and quarry dust. The lateritic
soil sample used was collected beside the Civil Engineering
laboratory, University of Benin at (06° 24' 01.326"N, 05° 37'
02.988"E) while the quarry dust samples used was collected from the
Structural Laboratory Unit of the Civil Engineering laboratory,
University of Benin at (06° 24' 11.310"N, 05° 37' 01.026"E). The
disturbed lateritic soil sample was collected at a depth of 1.5m and
transported to the Civil Engineering Laboratory. The lateritic soil
was air dried for five days to allow for partial elimination of natural
water and then sieved with sieve no. 4 (4.75mm opening) to obtain
the final soil samples for the tests. This lateritic soil sample and the
quarry dust was mixed at 5%, 10%, 15%, 20% and 25% by weight
and the following test were performed; particle size test, specific
gravity, Atterberg limit and compaction. From the laboratory test
carried out, it was observed that the soil is of the clayey sand soil
type of medium plasticity with a specific gravity of 2.13, a liquid limit
of 29.5%, and a plastic limit of 19.37%, an OMC of 14.6% and an
MDD of 1.68mg/m3. When compared with the specifications of the
Federal Ministry of Works and Housing (FMWH), the soils with
these values are not suitable for use as construction materials as they
usually have low shear strength and are more susceptible to the
shrink-swell behavior. However, at 25% replacement quarry dust
replacement, the specifications were satisfactory with a liquid limit
of 23.8%, a plastic limit of 10.28%, an OMC of 11.90% and a MDD
of 1.73 mg/m3, which conform to (FMWH) standard. However,
regarding ANOVA analysis carried out, the null hypothesis was
rejected at 5% level of significance showing that there is a significant
difference in the percentage replacement of the lateritic soil sample
with quarry dust.