Physical Properties

Uretek Compressive Strength: More Than Satisfactory.

The URETEK polymer is primarily used to consolidate ground and to relevel settled structures. So from a practical point of view, the most important property is compressive strength.

The compressive strength of Uretek injected materials is more than satisfactory for for the usage applications outlined in this website.

Elastic characteristics

Within certain limits the URETEK polymer demonstrates elastic characteristics. Hooke’s Law states that compression is proportional to applied forces and will not exceed more than 10% in deviation.

Only when force exceeds the elastic limit is the internal cellular structure permanently modified. The elastic limit depends on the density of the material.

The Effect of Density on Compressive Strength

The diagrams indicate the effect of density on the resistance to compression of typical Uretek resins.

The usual surface density of the URETEK material, which is about 70kg/m³ when injected beneath flooring, can reach more than four times that figure in Deep Injection levels.

Strength to Weight Ratio

A significant characteristic of Uretek materials is their strength to weight ratios.  A confined cubic metre of Uretek with a mass of 50 kg would be able to support a load of some 40,000 kg.  In practice however, when used for lifting (say) 40,000 kg/m2 (40 tonnes), the applied density will be in the order of 150 kg/m3, ensuring the necessary factor of safety against creep.

Service Life and Durability

Underground, Uretek materials are intended to last 100 years.  “The service life of Uretek material can be relied on to exceed 30 years . . . and can confidently be expected to be considerably longer.” 

In addition to low thermal conductivity, it is stable and durable.

Ageing Underground

Uretek materials are exclusively used underground. Intensive testing on such materials buried for 10 years indicated no significant loss in density, compressive strength or dimension, relative to control samples aged indoors.

Environment and Ground Water

Uretek material is inert and will not leach into ground water nor affect the environment.

Moisture Resistance

Unique hydro-insensitive resin is used in wet conditions, including below water table level, to ensure structural quality material.

Fungi and Bacterial Resistance

Fungi, bacteria and mould do not decay Uretek

material.

Insect Resistance

Uretek materials do not nourish insects or rodents.

Biodegradation

Uretek material will not be subject to biodegradation, even when buried underground.

Stability in Sunlight and UV

Surfaces exposed to sunlight will discolour and embrittle but are then likely to shield underlying layers.  Because Uretek material is exclusively used underground, this is generally not relevant.

Stability & Chemical Resistances

Uretek materials are thermoset polymers.  Thermoset polymers are those that change irreversibly during their formation reaction into a material that is infusible and insoluble.  The stability of poly-urethanes is well documented and a table of chemical resistances is given on the page about Chemical Resistance.

 Creep under Dynamic Stress

Long term performance is mandatory.  According to highway research, resin layers should not exhibit any creep deformation under normal traffic loads.

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