Horizontal And Vertical Extension Of RCC Buildings

 It is most usual that extensions to the buildings are required to be carried out in view of necessity of  more area requirement in the building. The limit of additional floors depends upon the strength of  columns mainly. Sometimes columns are erected very near to the building and additional floors are  provided.

 Horizontal extension of existing building adds to floor area at the same level which is required many  times rather than one above the other. Normally this is provided by constructing columns near  the  existing columns and also farther as required and floor provided. Horizontal extension of about  1.2  mtrs.  which has to be cantilever, is not feasible with R.C.C. and cannot be thought of in view of  anchorage  problem, high moments of cantilever beams and slabs and beam with wall load at the  edge of extension.

 Extension activity to building cause nuisance to occupants such as sound, dust, traffic etc. Also open  space around building is occupied by shuttering material, cement, sand site office etc. It can be said  it is  a great nuisance to the occupants.

 Vertical extension with ferrocement columns, beams, slabs is much convenient. It is possible to have  more additional floors. Since ferrocement has much less self-weight about 50% as compared to  RCC.,  ferrocement columns, beams are of small sections and ferrocement slabs are thin, say about  40 – 50mm  thick. This is because ferrocement is much strong material. In view of small section  reinforcement and  very high bond strength development, permissible stresses in ferrocement are  much high as compared  to RCC. Therefore extension of building with ferrocement columns, beams,  slabs can have more  additional floors than that is possible with RCC. At extra expenditure of  removing the existing load of  brick work etc. from existing floor, it can be possible to have still more  additional floors.

 Horizontal extension of building with Ferrocement Technology is most convenient upto overhang of  1.2  mtrs. or more depending upon available strength of columns and beams on the periphery of the  building.  The extension is provided using the precast ferrocement beams, slabs, panels manufactured  on  machinery set up duly anchored to the building at floor level. The anchoring is done by using  innovative  indigenous method. The precast cantilever beams as well as beams at the edge are  manufactured on  machinery set up in the form of ‘U’ incorporated with the reinforcement for the  beams. The joints  between the precast beams and the building are duly connected by wiremesh  lapping and welding and  matrix applications. After this plane vibrated concrete poured in the hollow  of beam.

 Vertical and horizontal extension by Ferrocement Technology is more convenient and feasible since  the  self-weight of ferrocement element is quite low. Also since the ferrocement element such as  beams,  slabs are manufactured away from the site cause less inconvenience to the occupants of the  building.  The time of providing extension work to the building at site is reduced by about 50% since  the activity of  precasting is carried out at other locations.