Full prefab open system
In this system, almost all the structural components are prefabricated. The filter walls may be of bricks on of any other local materials
This system is based on the use of large prefab components. The components used are precast concrete large panels for walls floors roofs balconies, staircases etc. The casting of the components could be at the sit on off the sit.
Depending upon the context of prefabrication, this system can also land itself to partial prefab system ad full prefab system.
Structural scheme with precast large panel walls can be classified as
1. Cross wall system.
2. Longitudinal wall system. Cross wall system:-
In this system the cross walls are load bearing walls. The façade walls are non-load bearing. This system's suitable.
In this system, cross walls are non-load bearing, longitudinal walls are load bearing. This system is suitable for low rise buildings.
A combination of the above systems with all load bearing walls can also be adopted.
Precast concrete walls could be :-
1. Homogenous walls.
2. Non-homogenous Walls. Homogenous walls:-
The walls could be solid, hollow or ribbed. Non-homogenous walls:-
Based on the structural functions of the walls. The walls could be classified as
c. Shear Walls.
Based on their locations and functional requirements the walls are further classified as.
i. External walls, which can be load bearing or non-load bearing depending upon the layout. They are usually non-homogenous walls of sandwiched type to impart better thermal comforts.
ii. Interla walls, which provides resistance against vertical loads, horizontal loads, fire etc. and are normally homogenous.
Types of precast floors:-
Depending upon the composition of units, precast flooring units could be homogenous or non-homogenous.
1. Homogenous foors could be solid slabs, cored slabs, ribbed or waffle slabs.
2. could be multilayered ones with combinations of light weight concrete or reinforced/ pre stressed concrete, with filled blocks.
Depending upon the way the loads are transferred the precast fllors could be classified as way or two way systems.
One way system:-
One way system transfers loads to the supporting members in one this direction only. The precast elements of this category are channel slabs.
Hollow core slabs, hollow blocks ad buttons plank system, channels and tiles system. light weight cellular concrete slat etc.
Transfer loads in both the directions imparting loads on the four edges. The precast element under thus category are room sized panels two way ribbed or waffle slab system etc.
Staircase system consists of single flights with in built risers and treads in the element only the flights are normally unidirectional, transferring the loads to supporting landing slbas or load bearing walls.
Box type system:-
In this system, room size units are prefabricated and erected at site. This system derives its stability and stiffness from the box make rigid connection among themselves.
The box unit rests on plinth foundation which may be of conventional type of precast