How It Works

DURALAY is an environmentally friendly, liquid chemical compaction & stabilizing medium which when added in small volumes to natural aggregates/soils and gravels results in considerable improvements in the physical properties of the compacted material thus enabling low cost durable roads to be constructed with a reduction in compactive effort.  Duralay surfaces are suitable for main and secondary rural, municipal and urban roads; runways; freeways; helipads; parking areas and anywhere that a good bearing capacity is required to take heavy vehicle traffic. 

Duralay affects gravels and soils as super plasticizers affect concrete materials. It increases the density of in-situ materials and stabilizes the clay in the material, improving the strength characteristics of the compacted soil (C.B.R.*increases of 100% – 300%) and resulting in costs savings of up to 75%.

How Does the Duralay Road System Work?

> Acts as a compaction aid in all natural gravels and soils.

> Acts as an ionic stabilizer in the clay fraction of proven natural gravels and soils.

When applied to the soil Duralay has the effect of increasing the compactibility of soil. Compaction in the field is greatly improved using Duralay and conventional compaction methods. This in turn increases the bearing capacity and at the same time forms a more impermeable layer than could be expected of the untreated material. The compaction is made easier due to its super plasticizing effect and its ability to reduce the moisture held by surface tension. The ion exchange is highly reactive in clay minerals because of a high surface area and charge (Ionic substitution). They therefore have an exchange capacity, which enables Duralay to not affect the clay structure, but just the clay properties. The reactive minerals include montmorillonite, smectite, vermiculite and iolite. Their presence, with the addition of Duralay will enable the engineer to obtain high densities of 100% + MOD AASHTO. This is achieved by closing in the air voids and coating the soil particles thereby stabilizing minerals and rendering them inactive.

Characteristics

DURALAY, by lubricating the soil particles on compaction, binds the particles closer together filling up the voids and attaining more strength and higher densities. Poor materials (or soils) that one would not have normally used would have been removed in the past, but can now be used and are upgraded with the use of Duralay soil stabilizer. Duralay should be applied in layers of 150 – 200mm. With clay type materials an iron exchange takes place which neutralizes the clay (stops any movement of the soil). Once again these clay type materials would under normal conditions be either removed or bridged over by importing several layers of good gravel material from a quarry which proves very costly.

Duralay Properties

pH: 0.8
Specific Gravity: 1.07
Colour: Clear
Viscosity CPS: 635

Method Of Construction

Chemically stabilized low cost roads using in-situ soils & gravels for road base compaction:

1. Mix DURALAYstabilizing product into water tanker at suppliers specified dosage.
2. Remove any wind blown sand or inert materials plus grass with a grader, by scraping the road to be treated.
3. Cut material (Soil) to form drain from both sides of road towards centre line therefore lifting road.
4. Pre shape road removing any slacks & bumps, cutting shoulder material onto road.
5. Rip proposed road base layer with grader to a depth of 15/20 cm thickness. (15cm is the generally recommended layer of thickness)
6. Spray ripped material with DURALAYapplication evenly over area with water tanker.
7. Mix application uniformly into base material using Motor Grader, Disk Plough or Rotavator.
8. Add additional water to base layer to obtain OMC (Optimum moisture content) as required.
9. Re-shape road to required profile with Motor Grader 2-3% camber.
10. Compact layer with Grid or Padfoot & finish off with Vibrating Roller Smooth Drum & PTR.
11. Curing of layer with frequent spraying of water is recommended for 3 or 4 days for surface.