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Frost penetration depth (frostdybde) for various materials in function of the freezing index (frostmengde) magnitude for a 4°C mean annual air temperature. Kult: Crushed rock material with upper sieve size in the range 90 to 300 mm (ex.: 22/150 mm). Knustfjell: Base course material well-graded crushed stone material with upper sieve size in the range of 16–63 mm. Sand: sand; Grus: gravel; Litt: a bit; Ikke: non; Telefarlig: frost susceptible; Udrenert: undrained; drenet: drained. (Vegbygging, N200, 2014).
Contexts in source publication
Context 1
... annual air temperature ranging from −2 to 8°C and for water contents varying from 1 to 8%, in accordance with aggregate's nature. Figure 4 and Table 3 illustrate typical frost penetration depths for various materials for a mean annual air temperature of 4°C and correction factors depending on material types, water content and mean annual air temperature. ...
Context 2
... the climate change variability should also be incorporated in the design phase and there- fore in the FI magnitude probability period of return. Table 3. Correction factors of the frost penetration depths of Figure 4 according to material types, water contents and mean annual air temperatures. ...
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Citations
... However, most of the classifications (frost susceptibility, thermal con ductivity, etc.) of the current specification is based on the Frost i Jord project (Heiersted et al. 1976) and do not account for the use of coarser rock materials. Consequently, severe frost heave problems have been observed in pavement and railway structures (Aksnes 2013, Loranger et al. 2017 where the subbase and frost protection layer (FPL) were made of coarse crushed rock. ...
... Ensuring reliable and safe tracks for railways (especially for high-speed railways) requires components of the railway superstructure and substructure with sufficiently high resistance to deformation [3], which can be caused by traffic load (static and dynamic load [4][5][6]) and non-traffic load (climate load-water, frost, snow, etc. [7]). At present, as thermal insulation or reinforcement materials in sub-ballast or sub-base layers can be used various polymer materials e.g., expanded polystyrene (EPS) [8], polyurethane [9], extruded polystyrene (styrodur) [10][11][12], artificial aggregates, liapor with foam glass [13,14], and geosynthetic materials (geogrids, geo-mattresses) [15,16]. The expanded polystyrene (EPS) in contact with subsoil is also used as isolation under (shallow) foundation [17,18] and under road pavement foundation [19]. ...
... The global error for both of these mathematical models is = 0.0117. Table 7 displays the difference ΔDF = DF,mat − DF,num between the calculated data using the mathematical model (Equations (10), (12) and (14)) and data obtained using numerical modelling found in Section 3. ...
The article aims to present the modified structural composition of the sub-ballast layers of the railway substructure, in which a part of the natural materials for the establishment of sub-ballast or protective layers of crushed aggregate is replaced by thermal insulation and reinforcing material (layer of composite foamed concrete and extruded polystyrene board). In this purpose, the experimental field test was constructed and the bearing capacity of the modified sub-ballast layers’ structure and temperature parameters were analyzed. A significant increase in the original static modulus of deformation on the surface of composite foamed concrete was obtained (3.5 times and 18 times for weaker and strengthen subsoil, respectively). Based on real temperature measurement, it was determined the high consistency of the results of numerical analyses and experimental test (0.002 m for the maximum freezing depth of the railway line layers and maximum ±0.5 °C for temperature in the railway track substructure–subsoil system). Based on results of numerical analyses, modified railway substructure with built-in thermal insulating extruded materials (foamed concrete and extruded polystyrene) were considered. A nomogram for the implementation of the design of thicknesses of individual structural layers of a modified railway sub-ballast layers dependent on climate load, and a mathematical model suitable for the design of thicknesses of structural sub-ballast layers of railway line were created.
... The natural subgrade soil was clay. For a more detailed description see Loranger et al. (2017). Table 1 lists the final layer thicknesses which were accurately measured during the construction process. ...
Transport infrastructures built on frost-susceptible soils may require insulation layer to
minimize frost penetration. In Norway, one of the approaches is the use of lightweight
aggregates (LWA) as an insulation layer, especially when there are specific restrictions for
pavement thickness. Performance and design thicknesses of LWA are included into the
Norwegian Road Design Handbook. The current regulations allow the use of LWA layers with
or without an underlying lower frost protection layer (LFPL). The goals of this paper are to a)
observe the frost insulation capacity of lightweight aggregates and b) investigate the necessity of
lower frost protection layer below the lightweight aggregate layer. A full-scale road test site was
built in Røros, Norway, with three sections using LWA for insulation purposes. For these
sections, a 0.6 m thick insulation layer of expanded clay (Leca) with particle size of 10/20 and
0/32 mm and foam glass (Glasopor) with particle size of 10/60 mm was constructed. An
underlying LFPL with a thickness of 0.7 m was made of crushed rock material with particle size
of 0/120 mm. Temperature was monitored for two winters (2016/2017 and 2017/2018). The
cumulative surface freezing index (FIs) for the two winters resulted in 22,630 and 36,683°C·h
respectively. Field observations show that the performance of all three insulations layers was
generally the same. The results showed that for both winters the frost front remained in the LWA
layer. The study shows that lightweight aggregates could be placed directly on frost-susceptible
soils and the frost front will remain in the 60 cm insulation layer even at FIs of 36,683°C·h.
KEY WORDS: Expanded clay, foam glass, lightweight aggregates, road insulation.
... However, LWA can also be used without any binder as a raw aggregate in various applications. Dense closed pores in LWA enable good thermal properties of such materials [7], offering frost resistive alternative to natural gravel or crushed rock material as main aggregates in base, sub-base and frost protection layers in cold regions [21]. Particularly in Nordic countries, LWA has been used in several applications in a number of projects over the last decades for insulation purposes, reducing settlements and improving stability of fills on soft subsoil [38]. ...
Deformation properties of lightweight coarse grained material from recycled foamed glass have been determined from large-scale triaxial tests on prismatic specimens with dimensions 40 cm × 40 cm × 80 cm. Deformations were measured locally using vertical and horizontal local deformation transducers. Monotonic and cyclic loading at small to medium strain range were conducted. Three load sequences representing the expected conditions of use of lightweight material as vibration-reducing material in railway geotechnics have been used. Results indicate strong effect of brittle cellular structure of tested material as well as confining pressure dependency of elastic threshold shear strain and damping ratio. The results were used to assess the applicability of empirical formulas for shear modulus of granular materials to lightweight foamed glass. The parameters determined from the laboratory tests were further used in numerical analysis of railway dynamic response. The results of the numerical simulations show that replacement of conventional ballast by leightweight material could improve the dynamic response of the track and reduce vibration.
In Nordic countries that experience seasonal frost, understanding how it affects the service life of linear transport infrastructures such as roads and railways is essential. Frost action both regroup frost heave and thaw weakening processes. This research focuses on frost heave, which occurs when three conditions are met: freezing temperature, water availability and frost-susceptible materials. Frost susceptibility is therefore defined as the ability of an unbound granular material (natural soil or crushed rock aggregate) to form ice lenses due to cryosuction, which is the suction of water to the frost front. Frost heave in a frost susceptible material lifts the layers above the freezing front. Many kinds of damage are attributable to frost heave, such as cracks in and unevenness of the road surface, making it uncomfortable and even dangerous for road users. Frost heave and subsequent thawing can significantly reduce the service life of roads and are accompanied by high associated maintenance and reparation costs. Knowledge of the frost susceptibility of the materials comprising the different layers of transport infrastructure is therefore crucial to optimal frost design.
This research mainly aimed to characterize the frost susceptibility of crushed rock aggregates. Laboratory experiments using a multi-ring frost cell were carried out to estimate the segregation potential of the 0-4 mm fraction of crushed rock aggregates. Twenty-four tests performed on nine different rock types found that crushed rock aggregates with a fines content of <63 μm between 11.6% to 25.5% are highly frost susceptible. The study found poor correlation between <63 μm fines content and segregation potential. The latter was used to characterize the frost susceptibility of the different crushed rock aggregates primarily for its capacity to estimate frost heave magnitude easily. The use of a grain size criterion, as presently used in Norway, seems to be efficient for dividing non-frost-susceptible from frost-susceptible aggregates, but does not allow estimation of crushed rock aggregates’ segregation potential with a good degree of confidence. As frost heave tests require a costly laboratory setup and specialist personnel, the segregation potentials of crushed rock materials were estimated using material index properties such as initial water content, liquid limit, mean particle size of the fine fraction and specific surface area of the fine fraction. This method is used by the Quebec Ministry of Transportation for soils, and the goal here was to assess the suitability of the methodology for use with crushed rock aggregates. It was found that estimation from material indexes gave segregation potential results within a range of ±15% compared to those obtained from frost heave tests. There was a direct correlation between the specific surface area of the fine fraction of a crushed rock aggregate and its segregation potential, from which an equation was developed. The study showed that the crushing phase had an effect on the frost susceptibility of the tested crushed rocks. Aggregates are more frost susceptible after the first crushing stage than after the third or fourth crushing
stages. The hypothesis that the fine fraction is enriched by weak minerals at the first crushing could explain this behavior, but further research is necessary before this theory can be presented with confidence.
The design was optimized by modelling three road sections with different frost protection layers using the SSR model and the I3C ME software. The fully-instrumented test site is situated in the Røros municipality where harsh winters are the norm, with the freezing index of an average winter equal to extreme winter event of regions such as Oslo, Trondheim, Narvik, Tromsø etc. It was found that the SSR model is suitable for both frost
penetration and frost heave estimation for thick (2.05 meters) layered road structures. The SSR also permitted the back-calculation of key parameters such as dry density, moisture content and segregation potential, making it useful for assessing existing infrastructure parameters. Using a segregation potential function, i.e. segregation potential according to time, was found to produce optimal frost heave estimations in a transient thermal regime.
