## 2 Design and Investigations Preceding Construction
### Clean Equipment  
Thoroughly cleaned equipment is a prerequisite to successful application of an NME stabilising agent. Although contractors are aware of this aspect, almost without exception, problems occur on the first day of operations as a result of using equipment containing residue from previous operations. The organofunctional silane modification [22] of a stabilising agent (i.e., bitumen elusion or equivalent polymer) is a reactive agent that reacts with any bituminous residue left in a water browser from previous operations. It has become the norm to expect reactions (as shown in Figure 3), questioning the quality of the stabilising agent when the NME stabilising agent is added to uncleaned water bowsers, resulting in the formation of \"blobs\" or sticky substances (Figure 3a,b) of bituminous materials that are unusable. In order to prevent such \"first day\" occurrences, it is recommended that equipment be inspected before being used on site for any NME stabilisation purposes. Figure 3c,d shows some results of pre-inspections done on \"clean\" equipment. Resolving Some Common Construction-Related Problems Experienced during the Stabilisation of Granular Materials Using New-Age (Nano) Modified Emulsions (NME)  
Compaction of a NME Stabilised Granular Layer under Moisture Conditions That Are Too Low or Too High  
In practice, compaction of a pavement layer under moisture conditions that are too low is easily recognised by observing the formation of small cracks that appear behind  
Figure 3: **(a,b)** Typical example of an anionic NME stabilising agent that has been added to a construction water bowser containing residue from previous operations and resulting in a reaction with the residue and an unusable “blob” of bituminous material; **(c,d)** typical examples of residue and the state of equipment found during the pre-inspection of “clean” equipment used by contractors for stabilisation of granular materials using an anionic NME. a smooth-drum roller used for compaction. These cracks are often misdiagnosed on site as signs of \"pumping\", i.e., too high a moisture content, which requires drying out of the material before final compaction. Such actions only worsen the situation, basically ensuring that the layer will not meet the minimum specifications as per Figure 1 or Figure 2.  
A typical example of such cracking is shown in Figure 4. It is always good practice to have a water browser on stand-by with a small percentage of diluted NME in the construction water. As soon as cracking is noticed, a light spray with the diluted NME solution can provide the necessary moisture to compact the layer as a solid unit. The additional NME solution also enriches the surface of the layer providing additional strength to the top of the layer. As a rule of thumb, water without a stabilising agent should never be used to increase the moisture on surfacing, as it lacks the binder required to re-establish bonding of the materials already affected through the introduction of cracking. Experience has shown that stabilisation of granular materials using construction water diluted with a material-compatible NME stabilising agent are quite resilient and forgiving in nature. In contrast to compaction under moisture conditions that are too low, the opposite can also happen. In the case of moisture conditions that are too high, a small \"wave\" or deformation of material can be noticed to move in front of the smooth drum roller. In such cases, there is no damage caused by ripping the layer and allowing the material to be exposed to the sun for some of the moisture to evaporate. Re-compaction of the construction layer has little (if any) impact on the engineering strength requirements to be achieved. In extreme cases, movement of the stabilised layer (even when walking on the layer) after some hours, can indicate stabilisation of a pavement layer to the wrong depth (too shallow), resulting in an overapplication of the stabilising agent in a thinner than specified layer.