Early studies on the utility of geocells and geogrids in reinforced road bases and the reinforcement mechanisms were carried out more than fifty years ago. These demonstrated that reinforcement with geocells and geogrids can improve bearing capacity significantly compared with unreinforced sub-bases and road bases. Since that time many efforts have been made to develop appropriate design procedures. SBRCURnet committee 1991 recently developed a novel design procedure applicable to unmetalled roads, concrete block paving and asphalt roads. Christ van Gurp from Kiwa KOAC highlights as principal author some aspects of the publication to be released by the end of 2017.
The SBRCURnet design procedure on road base reinforcement makes use of the widely known procedures of Giroud-Noiray and Giroud-Han for designing the thickness of the road base of unmetalled roads. By matching the results to the outcome of the software code BESCON, the Dutch procedure for the thickness design of block paving, conversion factors could be derived to provide for a simple approach for designing road base reinforcement in road infrastructure with pavers. A really innovative step was set in the design of road base reinforcement in asphalt roads. The novel approach was tailored to fit into the standard Dutch mechanistic empirical design code OIA. The reinforcing effect is expressed in a combination of support improvement factor and modulus road improvement factor, both to be seen as factors of enhancement of the bearing capacity of the road base by reinforcement.
Kiwa KOAC has developed laboratory testing procedures for the assessment of the design parameters of kinds of types of geocells and geogrids for unmetalled roads and asphalt roads. Testing requires a series of tests in which the development of permanent deformation with number of load cycles in the unreinforced and reinforced situation is investigated for a few levels of structural support.
Voor meer informatie kunt u contact opnemen met:
Jacob Groenendijk (senior adviseur)
088 562 2528