Investigation of Geogrid Performance on Highway Subbase By Using The Pullout Test Device

Sert T., AKPINAR M. V.

TEKNIK DERGI, vol.22, no.1, pp.5285-5304, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 22 Issue: 1
  • Publication Date: 2011
  • Journal Name: TEKNIK DERGI
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.5285-5304
  • Recep Tayyip Erdoğan University Affiliated: No

Abstract

In this study, the shear strength performance of geogrids that are used reinforcement on highway subbase are examined. For this purpose, a special designed pullout test device is developed and used. The test device is first to be used in Turkey which is in 1m length x 1m width x 0.80m in height dimesions. Three different aperture size geogrids with 3 cmx3cm, 4cmx4cm, 5cmx5cm dimesions are used in the tests. Shear strength- time variations are investigated. The horizantal displacements of geogrid samples are determined both diplacement sensor and image technic. It has been observed in all of the test made by geogrid types that while soil parameters, vertical pressure loads and pullout speed are maintained constant during the tests as the tensile force is applied to geogrids, pullout force inclines to a peak point and after this point it starts to decline. It is concluded that geogrid aperture size has effects on highway subbase shear strength and displacements due to the pullout force are so small that they can be ignored.

In this study, the shear strength performance of geogrids that are used as reinforcement on highway subbase are examined. For this purpose, a specially designed pullout test device is developed and used. The test device is a first to be used in Turkey which has dimensions of 1 m length,1 m width and 0.80 m height. Three different sizes of geogrid dimensions are used in the tests with apertures 3 cm x 3 cm, 4 cm x 4 cm, 5 cm x 5 cm, respectively. Variations of shear strengths of geogrids due to time are investigated. The horizontal displacements of geogrid samples are determined both by image technique and diplacement sensors. It has been observed in tests for all the geogrid types that while soil parameters, vertical pressure loads and pullout speed are maintained constant and the tensile force is applied to geogrids, pullout force increases to a certain peak point, where it starts to decline. It is concluded that geogrid aperture size has a considerable effect on highway subbase shear strength and displacements while the effect on the pullout force is negligibly small.