Dear reader we were discussing about comparison between soil and concrete as construction materials and purposes.
Concrete, we used in construction, can be inspected in laboratory before use. We try to provide similar stress condition, identical materials and identical moisture content (w/c ratio) of that will be delivered to site for placing for a project. In case of soil, we also perform some laboratory and field tests to have idea about behavior of soil. Some field tests are
-plate load test
-pile load test
-standard penetration test
-vane shear test
-some geophysical tests etc.
We have discussed some tests and some are to come in this blog. In case of laboratory test the main uncertainty results is collection of undisturbed sample. In many cases we have to make sample or use remolded sample. We have discussed that practically it is impossible to collect undisturbed sample.
Least undisturbed sample can be derived from block sampling but it is suitable for shallow depth. In borehole sampling, sample disturbance results a sample that don’t represent in-situ conditions.
Soil is unpredictable in nature which leads to change in properties not only with location but with also depth at a same place. The behavior of soil varies not only with types but with also conditions it is subjected. Its properties depends on -change in environmental condition
In case of concrete, we deals with engineering properties like
-modulus of elasticity
We can design it with these properties which are known to us by testing or any other means. In contrast to concrete only two/three parameters cannot be used to characterize soil and many factors contain in its engineering properties. So to perform a design work elaborate testing of soil is required to determine its characteristics.