Fatih Celik

Examination of the mechanical properties and failure pattern of soilcrete mixtures modified with rice husk ash

Abstract This paper evaluates the unconfined compressive strength (UCS), stability (bleeding), modulus of elasticity and failure patterns of cement-based grout mixtures that were prepared by placing of rice husk ash (RHA) with cement at various water to binder (w/b) ratios. In order to investigate these parameters, UCS and bleeding tests were conducted on the soilcrete samples that prepared at 5, 10, 20 and 30% replacement level of RHA with cement for .75, 1.00 and 1.25 w/b ratios. Test results showed that the UCS values of the samples for 28 day curing are higher than 1 MPa and E/q u ratios obtained from soilcrete mixtures were less than the corresponding value from slurry clay–cement mixes given in the literature. In addition, all bleeding test results are lower than the level of .5%. Finally, most of the mixtures prepared for this study failed along foliations.

Effect of sand column on compressibility and shear strength properties of peat

Abstract Peat is found in many countries throughout the world where it can be generally seen in thick layers in limited areas. Peat is an extreme form of soft soil and is considered problematic due to the low shear strength and large compressibility. This project presents laboratory finding on the compressibility and shear strength characteristics of fibrous peat with sand column. The peat used in the study is classified as fibrous peat and H1–H4 in Von Post scale. Its liquid limit is 119%. In all tests, the peat used for the tests passing 2 mm and remain on .15 mm. The rounded sand used for making sand column is poorly graded passing from 2 mm sieve size and retaining on 1 mm sieve size. The tests conducted to investigate effect of area ratio of sand column on shear strength and compressibility of the peat. Three different area ratios were used for both compressibility and shear strength tests. Consolidation test results showed that when the area ratio increases compressibility characteristic of the peat improved. Shear strength of the organic soil was also affected from the sand column.