MEASUREMENT OF TENSILE STRENGTH OF COMPACTED SOIL.

Abstract

This study deals with the measurement of tensile strength of compacted soils by different methods and their correlation with unconfined compressive strength. Different tests that have been performed in this investigation are: a) Flexure test with central point load on soil beams - Beam test.•b) Direct tension tests - (i) Briquette test and (ii) Cylindrical specimen test. c) Indirect tension tests - (i) Split test on cylindrical specimens (ii) Side split test on cubical specimens (iii) Split test on prismatic specimens (iv) Diagonal split test on cubical specimens. Tests have been programmed with different initial moulding water contents and different dry densities, in order to assess the variations in tensile strengths measured by each of the above mentioned methods. All the tests programmed have been run on samples compacted with different compactive efforts namely, the proctor compaction and the AASHO compaction. All the different methods adopted in this investiciation indicated that, the tensile strength of compacted soil specimens increases with the moulding water content upto a moisture conceit about 2% dry of optimum moisture content where the tensile strength is maximum, and then decreases with further increase in moulding water content. The test results have shown that the unconfined compressive strength is three timesthat of the iii flexural tensile strength and is six times that of tensile strength rneasurE;d= by split tests and is five times that of tensile strength measured by direct tension tests. Test results on cube-diagonal split tests and cylinder split tests have shown that the tensile strength increases with increase in dry density at any particular moisture content whereas it decreases with increase in moulding water content at any particular dry density.