Foundation classes

The foundation consists of the sub-base layer and the capping layer (if used) and is constructed with unbound or hydraulically bound materials. Depending on the type of materials used, the methodology distinguished four foundation classes, on the basis of foundation surface modulus. 

Class 1 Unbound selected granular material or stabilised granular material as perTable 10.2 S50 

Class 2 Unbound crushed, selective granular or with asphalt arisings material as perTables 10.4 and 10.5, as well as bound materials such as CBGM A or B as perTable 10.10, or soil cement achieving compressive strength of at least C3/4 SlOO 

Class 3 Cement-bound granular material CBGM A or B as perTable 10.10 achieving compressive strength of at least C8/I0 200 

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National Sanitation Foundation. Class II (laminar flow) biohazard cabinetry. Standard No. 49. Ann Arbor, MI 48105. 1976. 

Software the ANACONDA software was developed in C+-1- language with Microsoft Foundation Class, it runs on MS Windows, and can be downloaded for noncommercial use from the website http //bioinformatics.ua.pt/aplications/ anaconda. 

The thickness of the foundation depends on the subgrade CBR or subgrade stiffness modulus, while the thickness of the pavement structure depends on the foundation classes and the traffic volume. 

Table 13.5 Foundation classes according to Highways Agency (2009a) and materials to be used...

Table 13.5 gives details of the foundation classes and the expected foundation surface modulus, while Figure 13.14 explains the foundation and surface modulus concepts. 

The foundation classes are limited to classes 1, 2 and 3. Foundation class 4 is excluded since it is considered essential to measure the properties of such a foundation during construction to give adequate assurance that the appropriate long-term foundation surface modulus is likely to be achieved. 

The in situ test for foundation acceptance is the determination of foundation surface modulus immediately prior to the construction of the overlaying pavement layers. Table 13.6 gives the unadjusted mean foundation surface modulus and the minimum foundation surface modulus values, for each foundation class and for different categories of materials, to be achieved or exceeded. 

The methodology also imposes maximum permissible layer stiffness values for each foundation class, regardless of the foundation design method employed. This is to minimise the... 

To conclude, the choice as to which approach and which foundation class is selected is usually made on economic grounds on the basis of the materials that are available, the size of the scheme and relevant costing information. The designers should give full consideration to the use of local and secondary materials. 

The determination of the foundation thickness in the case of restricted design is carried out with the use of design charts shown on Figures 13.17 and 13.18. In all cases, the designer chooses the foundation class, and for a given subgrade CBR or subgrade stiffness modulus, the total foundation layer thickness is determined. 

There are a large number of possible designs for the various combinations of subgrade surface modulus and foundation material, in order to achieve the desired foundation class. 

When two-layer foundation design is chosen and the foundation class is 2, the chart in Figure 13.18 can be used for the determination of the layer s thicknesses. 

It is noted that EME2 is recommended to be laid over a foundation class 3 or 4 or foundation class 2 that has a surface stiffness modulus of at least 120 MPa at the time of construction. 

Thus, by knowing the cumulative number of ESAL, the foundation class and the type of asphalt to be used in the base and binder course, the total asphalt thickness is determined (see Figure 13.19, right-hand portion). 

The methodology uses the foundation concept as in flexible pavements. Out of the four foundation classes established, class 1 is excluded for rigid pavements. 

The determination of the slab thickness is related to the traffic expressed in ESAL, the foundation class and the flexural strength of concrete. 

The strength of the subgrade is expressed in CBR or stiffness modulus, and from this, the foundation thickness is determined for the foundation class chosen to be used. Out of the four classes established, foundation class 1 cannot be used for rigid pavements and bound foundation class 2 can be used only upon approval of the overseeing organisation. 

The foundation classes and the foundation design procedure are the same as those in flexible pavements and are outlined in Section 13.5.3. 

The Industry Foundation Classes (TEC) model architecture has been developed using a set of principles governing its organization and structure. These principles focus on basic requirements and provide a structure for the model together with a framework for sharing information between different disciplines within the AEC/ FM industry. 

The acquired data were analyzed using laboratory-developed software based on Microsoft Foundation Class (MFC) of Visual Studio 2008 (Microsoft, Inc, USA). The procedures were performed to control the keyboard for game operation using acquired FMG signals. Two steps were carried out initialization (step 1) and real-time process (step 2). 

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