The design institute Magistral TsDMP (Voronezh) developed a road pavement structure utilizing two interlayers made of woven geotextiles:
• Geospan GT PP 80 reinforcing interlayer at the interface of М-600 macadam layer (fraction of 40 to 70) and the sub-base course;
• Geospan GT PP 33 separating and capillary-breaking interlayer on overwatered heaving soils.
The aggregate reinforcement with Geospan GT PP 80 woven geotextile of high strength provides a possibility of decreasing its thickness by increasing its elastic modulus that results in higher availability and serviceability (extended life span) of the road structure. CREDO RADON-assisted calculations of the road pavement allowing analysis of various variants comprising reinforcing interlayers were carried out. An extent of influence of Geospan GT PP geotextiles on a road pavement calculation in terms of frost resistance has been approved by the federal institute ROSDORNII. According to an expert opinion, in subgrade structures with reinforced interlayers road pavement frost resistance is secured at enhanced soil frost heaving values. Such a progress is facilitated by a strong geotextile’s pressure applied to certain points of the subgrade where the heaving values exceed an average heaving value for the section considered, which results in a decrease in uneven heaving. Based on the calculation results, the thickness of the draining and frost-resistant sand layer of the road pavement base was reduced.
Technical and economic effectiveness of the structure developed was confirmed by the road pavement calculations and a proven track record of utilizing similar structures on heaving soil sections during the overhauls of Kaluga region road network during 2010 to 2013.
The civil works under this project were carried out by SU-920 OAO (part of HMDC OAO and DSK Avtoban AO) in 2014. The total volume of Geospan GT PP geotextiles supplied amounted to over 160,000 m2.
