Page 153 - RoadCem Manual - PCT BV

Breaking strain
The breaking strain is the strain that is created by a high load and whereby instantaneously a crack occurs. At wharfs where high loads regularly occur the breaking strain is an important property when dimensioning for a cement bound construction.
Check remaining aspects
As well as the mechanical properties other aspects can have an influence on the construction thickness, such as possible frost/thaw damage. In areas where frost does not occur (less than 4 days with temperatures below -4 oC) or the level of the capillary water is lower than 1 m no measures need to be taken. When there is chance of frost/ thaw damage then precautions are needed and the advise is to contact the engineers at PCT head office.
5.9 Surfacing
5.9.1 General
Once the pavement load bearing structure is in place it is advisable to apply some kind of surfacing finish to the road. Many different methods of surface finishing are in common use and discussing all of them is beyond the scope of this manual. What is presented in this manual is a brief review of some of the available options. The possible options that are discussed in the manual are:
• Concrete
• Bricks
• Asphalt
• Wearing layer
• Sand up
• Gravel layer
• Chip and spray, etc.
The decision on the most suitable option will be affected by requirementes of the client, the availability of suitable materials locally and the economic considerations. In principle a wide range of aggregate types and qualities can be used for different surfacing options. Each of various types of surfacing has different requirements as regards the necessary materials and equipment for placement.
5.9.2 ConcreCem Fine Aggregate (sand) Concrete Finish
This option is durable and strong. It has a good wearing resistance characteristics and is impermeable to water so any precipitation on the surface will have to be evacuated through an appropriate runoff collection system.
The surfacing layer is applied on top of the pavement structure (in situ material stabilized with RoadCem and Cement) Figure 5.40. The Concrete can be placed either manually or using specialised equipment as in Figure 5.41. The finished surface is shown in Figure 5.42.
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