Civil Insight: A Technical Magazine Volume 3 | Page 16

Manandhar S. and Karki S.S.
Civil Insight (2019) 15-20
2) Materials and Methods
Two types of soil were used to conduct this research, namely Lateritic soil (Low plastic clayey silt) and
well-graded gravelly sand. The properties of both soils are presented in Table 1. The main aim of this
research is to improve the strength behaviors of the ground comprising fines greater than 80% by mixing
Table 1. Index and physical properties of Ratmate soil (red soil)
Properties
Specific gravity
Moisture content (%)
Gravel (%)
Sand (%)
Silt (%)
Clay (%)
USCS (Soil classification)
Liquid limit (%)
Plastic limit (%)
Plasticity index (%)
Optimum Moisture Content (OMC, %)
Unconfined Compressive Strength (UCS, kPa)
Ratmate soil (red soil)
2.48
28
6.61
73
20
ML
36.5
26
10.5
17.78
208.0
Table 2. Experimental conditions of Ratmate
Descriptions
Adjusted initial water contents (%)
Amount of Cement (%)
Atmosphere curing time (Days)
Experiment adjustment
17.7
3, 5, 7, 10
7, 14, 28
another well graded gravelly sand and different percentages of cement content cured for different curing
periods of 7, 14 and 28 days, as shown in Table 2.
The Portland Pozzolana Cement (PPC) of Standard Type-I from Jagadamba Cement Company in Nepal
was used to perform the research. The consistent mixing method is applied to prepare mixed sample of soil
and cement accurately. Initially, cement and soil were weighed in required proportions and blended well
for five minutes. Then, the amount of water required was further added to the mixture and blended smoothly
for another five minutes in order to obtain the homogeniety in the mixture.
3) Results
Samples were prepared at two states at defined maximum dry density and optimum moisture content by
remolding at laboratory. The samples were prepared before and after treating the soil with cement. The
UCS tests were performed for Ratmate soil before and after the cement treatments. The strength of Ratmate
soil before cement treatment was found to be 208.00kPa, as shown in Table 3.
The improved strength of Ratmate soil after cement treatment at different curing days is shown in Fig. 1.
The maximum UCS value of the Ratmate soil was obtained as 1254.38kPa for 7 curing days when treated
with 7% cement. Similarly, the minimum UCS value was obtained as 480.31kPa when treated with 3%
cement cured for same 7 days. Also, the UCS value was increased up to 1179.64kPa with 5% cement
content, but when cement was increased up to 10%, the UCS value was decreased to 828.34kPa, as
presented in Table 3.
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