Abstract
This study relates the recent developments that have taken place
in soil stabilization techniques to low-cost housing in Pakistan. The
investigation has been carried out in three distinct phases.
The first phase of this study undertakes a brief review of the
housebuilding in the country. A survey of the building materials in a
selected region helped remove a handicap due to lack of factual informa¬
tion in this sphere. None of the existing building materials, due to
their scarcity and high costs, was found to be within the means of the
common man. Attention therefore had to be focused on earth which inspite
of it3 shortcomings continues to provide shelter to a vast majority of
the population in the Indus Plains. A study of earth housing in these
plains as well as in some other developing countries helped isolate
problems associated with the use of earth as building xaaterial. Rainfall,
particularly in conjunction with winds, was found to be one of the important
factors responsible for bringing this most abundant of the building
materials into disrepute. In recent years an extensive use of soil stabili¬
zation techniques ha3 been made in connection with the highway and airfield
construction in other parts of the world. An application of the knowledge
and experience gained in this field to revitalize earth housing is found
to be the only realistic approach to the housing problem in the Indus Plains.
The second phase, which forms the core of this project, deals in
classifying and locating the soil3 of the Indus Plains for the purpose of
their planned use in stabilized earth housing. All soils encountered in
the region are classified into major groups based on their identifiable
characteristics significant from a stabilization viewpoint. This
objective was achieved through the cooperation of a soil survey agency.
i.
Soil information thus obtained i3 presented in the form of simple yet
comprehensive Soil Maps. These maps provide ready information about
all the important aspects of soil for undertaking a stabilized earth
project. The problem of identifying the soil, upon which rests the
whole success of this technique, is therefore almost completely solved.
After the soil has been correctly identified it only remains to determine
the requirements in terms of cement, water and compaction for achieving
tie desired results.
The third phase of this investigation was devised to determine the
above requirements for each soil group so as to eliminate the need for
elaborate testing on every site. This involved stabilization of repre¬
sentative samples of all major soil groups in the laboratory with
varying amounts of Portland cement. The specimens thus prepared were
tested for durability. Results obtained from soils stabilized with
fairly low cement contents compared favourably with those of burnt brick.
Based on these results the quantity of cement, amount of moisture and
compactive effort needed for each soil group is recommended
This study has thus provided answers to all the practical problems
of soil stabilization for low cost housing in the form of simple reference
maps.
