Design of expansion joint

Design of expansion joint:

1. Basic Dimensions

This is the dimension between the axes defined by the dimensional grid. The dimensional grid is the two dimensional co-ordinate system of reference line defining the layout of the buildings

2. Nominal or theoretical dimensions

It is the planned dimension of the prefabricate arrived from it's basic dimension and it's joints.

3. Actual dimensions

It is the dimension of the prefabricate when produced

If the interdependent arrangement of the basic dimensions of the building based on

the primary unit accepted components so that they apply to any building that is laid out on the 10cm (4') modular basis without cutting or altering at the

site.

5. Planning module (M_p)

It is a multiple of the basic module for specified applications. The planning module Mp = 3 cm is the common horizontal dimension or M_p= 1M is used for the vertical dimension, when M_p=60 cm for the length dimensions.

6. Modular grid

This is a particular case of the dimensional grid consisting of two dimensional co-ordinate system of reference lines (modular lines) at a distance equal to the basic module or the mult module (Mp). This multi module may be the same or different for each of the two SCEdimensions of the reference system. The area between the modular lines is called the modular zone of the component. The dimensions of the prefabricates are fixed from the modular grid by fitting in the elements after taking into account their tolerances and dimensions of the joints.

The limits of tolerances are based on the manufacture and erection requirements.

Production tolerance (T)

The limits of deviation in the dimensions  the shape of the prefabricates. This depends very much on the type of moduls, wooden, steel, concrete or plastic, the tolerance also depends on the nominal dimension, nature of prefabricate and its position during casting.

Erection tolerance

These are the limits of deviation of the positioning in the assembly of the prefabricates. The position tolerance are normally defined by five components namely, deviation in positioning of the prefabricates in x,y,z directions (  x,  y,  z) and deviation  in positioning with respect to another prefabricate ( p)and the deviation in the verticalioty of the