## 5 Construction of NME Stabilised Granular Pavement Layers--Practical Aspects
### NME Stabilisation Using Conventional Mixing Equipment (Water-Bowser and Grader)
#### 6.4.3 Construction and Upgrading of a Secondary Rural Road  
The construction process for all categories of roads using conventional equipment is similar in nature as described under the previous sections. In this example, material was also imported on a compacted in situ prepared roadbed. Material of a G7-quality (refer to Figure 1) was used to construct a single 150 mm thick layer on top of the prepared base-layer. Only one grader was used in the mixing of the material. The construction process and condition 6 years after completion of this secondary road are shown in Figure 17.  
4.4 Construction and Upgrading of a Local Access to Farms and Villages/Townships Using In-Situ Materials  
The depth to which the in-situ materials need to be stabilised is determined during the structural design process for the different material sections identified along the length of the road as per the detailed design method [6; 27]. Independent of the requirements and decisions with regard to the level of the labour-intensive construction to be implemented, the following basic steps need to be followed, as shown in Figure 19:  
* The in-situ material needs to be ripped to the required depth;
* Over-sized material (usually more than 1/3 of the thickness of the layer) needs to be removed. This can be done manually and the stone used for the protection of drainage facilities if required;
* The ripped material needs to be windowed, enabling the layer below to be compacted to the minimum required Dynamic Cone Penetrometer (DCP) penetration levels required for the layer at that depth within an applicable climatic zone (Appendix C and D in Reference [27]). This process will also ensure that the material to be stabilised is constructed to the correct thickness. DCP penetration rates per blow (DCP-DN values) as per the recommended design method [27] can be used for a quick and easy quality control for the compacted layer on which the stabilised layer is to be constructed;
* The material can either be mixed with the stabilising agent by hand and transferred back onto the compacted layer or transferred back and mixed using conventional equipment such as a grader and water-bowser with compaction equipment. Compaction for Category D and E roads [27] can be achieved using small pedestrian-type construction equipment to achieve the required densities. For Category D and E roads, the densities can also quickly and easily be determined using the DCP equipment to evaluate the required DCP-DN values for that specific layer [27];
* The top of the base-layer should be treated with an anionic silane-modified nano-polymer to ensure that a firm base-layer is achieved with a high-water resistance and protection against any possible damage, especially if it is to be opened to traffic before the surfacing is applied. For implementing agencies requiring a \"natural\" soil look to an upgraded gravel road, a second application of the anionic silane-modified nano-polymer is recommended. The anionic silane-modified nano-polymer can easily be applied by hand or sprayed by water-cart onto the finished base-layer. Suitable application rates for the treatment of the base-layer should be determined using trail sections. An application of 2 L/m\({}^{2}\) of a diluted treatment (as per supplier recommendation) is suitable for the priming of an unstabilised base-layer. Stabilised base-layers will normally require a lesser application rate; and
* A suitable surfacing can be applied using mostly hand-mixed materials such as slurries and sand seals, and for a more durable surfacing, even an NME binder Cape seal [19] using labour-intensive construction options can be used, as illustrated in Figures 18 and 20. An example of the construction of pavement layers using an anionic NME stabilising agent for the upgrading of tertiary access roads is shown in Figure 21. The slurry application by hand can be done similarly to that shown for the Cape seal without the single seal using an NME binder to provide water-resistant, cost-effective protection to lower-order roads.