Page 66 - ICJ Jan 2023

TECHNICAL PAPER COLLECTOR’S EDITION

some soils when the cement percentage is Expansion due to saturation can be treated
around 5.0. The increase in strength values as a measure of dimensional stability. Block
will be significant for soils containing performance when subjected to alternate wetting
montmorillonite clay for low cement and drying cycles can be easily quantified by
percentages of about 5 percent. There will monitoring the weight loss. Details of these two
be marginal variation in strength for soils tests conducted on pressed soil-cement cubes are
containing only kaolinitic clay. However, discussed in the following sections.
for some soils strength decreases as
the sand content goes up. This may be
attributed to reduction in clay size fraction
containing some non-clay minerals which
are beneficial for strength gain due to
some secondary reactions such as lime-
pozzolona reactions.

(iii) For higher cement percentages of the
order of 10 percent, the strength variations
are only marginal, when the sand content
of the soil is increased. However, for some
soils the variation is slightly more but
not to the extent noticed in low cement
contents.
Fig 4 Effect of sand content on strength for 10 percent
cement
(iv) These tests indicate a desirable sand
content in the range of 70±5 percent from
the strength point of view. Eventhough,
for some soils higher sand content does
not lead to significant improvement in
wet strength but it is probably useful in
improving the durability characteristics of
soil-cement. This aspect will be discussed
in the following sections of the paper.

EFFECT OF SOIL GRADING ON
DURABILITY CHARACTERISTICS OF Fig 5 Soil-cement cubes before and after weathering
SOIL-CEMENT BLOCKS test

Durability is an important aspect for successful
utilisation of any new building material for ALTERNATE WETTING AND DRYING
construction. Dimensional stability and the TESTS ON SOIL CEMENT BLOCKS
performance of the block subjected to alternate ASTM D559-82 code gives specifications for wetting
wetting and drying cycles are the two aspects and drying tests of compacted soil-cement mixtures.
indicating the durability of the soil-cement blocks. The procedure involves monitoring the weight loss

The Indian Concrete Journal | November 2018 67