Recycled Polyester Geosynthetic Influence on Improvement of Road and Railway Subgrade Bearing Capacity— Laboratory Investigations

Abstract

After years of using geosynthetics in civil engineering and infrastructure construction, it has recently become necessary to consider the possibility of recycling and reusing these materials. This paper presents the results of laboratory tests of the effect of recycled geogrid on the bearing capacity of soils using a CBR test. A polyester geosynthetic was selected for testing due to its high resistance to biodegradation and wide application. In a series of laboratory tests, two types of road and railway subgrade were used, mixed with geosynthetic cuttings in two different weight concentrations. The aim of the research was to demonstrate whether old demolition geosynthetics could be used to strengthen road and rail subgrade as recycled material. The influence of the geosynthetic cutting shape was also considered. The obtained results confirm the possibility of using recycled geogrid to improve the bearing capacity of the pavement subgrade, at least under these laboratory conditions. In the case of sand, the use of 2.0% additive causes that the poorly compacted soil obtains sufficient bearing capacity for the layer of road improved subgrade. As expected, the level of this improvement depends on the type of soil and the shape of geogrid cuttings.

Comprehensive Review of Geotechnical Engineering Properties of Recycled Polyethylene Terephthalate Fibers and Strips for Soil Stabilization

“…These variations are considered insignificant in terms of compaction. In other words, the addition of recycled fibers does not have a significant influence on the maximum dry density and optimum moisture content values, suggesting that compaction efforts may not be significantly affected by the fiber addition [83].…”

“…The maximum enhancement in the CBR was observed when utilizing 4% PET strip content with the ARs of 1, 2, and 3 [128]. Malicki, Górszczyk and Dimitrovová [83] conducted a study to investigate how moisture content and the addition of recycled PET strips impact the enhancement of the CBR. The highest CBR value was attained with 11% moisture content and 2% PET strip content.…”

“…Incorporating recycled PET strips into the soil can improve its strength and stability, resulting in an increase in the value of the CBR [133,134]. [128], (b) [129], (c) [130], and (d) [83]. [128], (b) [129], (c) [130], and (d) [83].…”

Experimental Analysis of Hot-Mix Asphalt (HMA) Mixtures with Reclaimed Asphalt Pavement (RAP) in Railway Sub-Ballast

“…In particular, mixtures modified with rubber and polymer returned interesting results in terms of fatigue resistance [ 31 , 32 ], mechanical properties [ 33 , 34 ], and damping vibrations [ 35 ]. Moreover, geofiber reinforced soil layers have been investigated [ 36 ] and were found to obtain a cost-effective alternative to soil improvement.…”

Performance Evaluation of Tunnel-Slag-Improved High Liquid Limit Soil in Subgrade: A Case Study

“…Yorulmaz et al [ 12 ] experimentally found the inclusion of an appropriate amount of waste marble powder could positively improve the bearing capacity of the subgrade soils of highly plastic silt and highly plastic clay. Malicki et al [ 13 ] presented the CBR test results of the effect of recycled geogrid on the bearing capacity of subgrade soft soils.…”