Effects Of Fibres On Development Of Cracks In Clay

This paper presents the results of laboratory tests on samples of clay reinforced with different amounts of synthetic fibres. The main objective of the paper is to investigate the effects of synthetic fibres on controlling desiccation cracking in clays. Samples of clay were compacted in thin layers with different fibre contents and tested for shrinkage cracking. Samples of reinforced clay were also used for index and strength tests. The results of the tests show that increasing fibre content reduces the density, the width and the length of cracks. Unconfined compressive tests and Brazilian tensile splitting tests indicate that by increasing fibre content both compressive and tensile strengths of the clay increase. However, the increase in tensile strength is considerably greater than the increase in compressive strength. Visual observations and image processing of the crack densities of samples show that by an addition of 3-4% fibre, by weight, into the clay, desiccation cracking can be fully controlled.