Classification of wallboard materials:

Mixed structure

Mixed structure houses with brick or block walls and reinforced or prestressed concrete floors. Because of its simple construction and low cost, it is the most widely used structural form; In order to improve its seismic performance, reinforced concrete structural columns are added at the junction of internal and external walls and the corner of external walls, also known as seismic columns. The structural column is connected with the ring beam of the building and roof to improve the integrity, strength and deformation capacity of the house. If the wall is built with hollow blocks, steel bars can be inserted into the holes of the blocks, and concrete can be poured into the holes to form reinforced concrete columns, so as to increase the seismic resistance of the house.

Prefabricated large plate structure

Prefabricated large slab structure is a kind of high industrialized building structure system developed after the Second World War. The main advantages are commercial production, high construction efficiency, low labor intensity, light weight, and better structural strength and deformation capacity than mixed structure. But the cost is high, large transport and hoisting machinery is needed, and the plane layout is not flexible enough. According to the building function, wallboard is divided into interior wallboard and exterior wallboard. The inner wall panel is mainly used as a load-bearing component, which is made of a single material. The exterior wall panel is generally non load-bearing wall panel, which has the functions of heat preservation, heat insulation, waterproof and so on. The structure is more complex, and some composite wall panels are made of a variety of materials. According to the different materials used, wallboard can be divided into concrete hollow wallboard, solid wallboard, lightweight aggregate concrete wallboard, industrial waste concrete wallboard, vibrating brick wallboard, etc. The connection structure of prefabricated large plate structure is the key to give full play to the strength, ensure the necessary stiffness and spatial overall performance of the house. Methods to strengthen the connection:

① The upper and lower wallboards and the steel bars protruding from the adjacent floors are welded;

② The four sides of the wall and the floor are slotted to increase the shear transfer capacity of the joint;

③ Concrete the joint as a whole. It is also useful to add vertical prestress in the wall to connect the floor and wallboard as a whole.

Internal force calculation: the strength calculation of wallboard, floor and its joints under vertical and horizontal loads shall be conducted. Internal force analysis of the wall: under the action of vertical load and out of plane horizontal load, the wall is calculated according to the vertical members supported on the roof, floor and foundation by fixed hinges at both ends; When the horizontal load is applied in the plane, the wall is calculated according to the vertical cantilever structure embedded in the foundation, and the influence of the joint work of the longitudinal wall and the transverse wall and the size of the wall opening are considered.

Cast in place wallboard structure

The cast-in-place wallboard structure is a house structure with cast-in-place concrete wall and precast or cast-in-place floor. The main advantage is good seismic performance. Compared with the mixed structure, the amount of wall plastering is greatly reduced, the labor intensity is reduced, and the amount of labor is less; Compared with the prefabricated large slab structure, the construction is simple, so it has developed rapidly. It has become one of the main structural forms of multi-storey and high-rise residential buildings in seismic areas of China. The wall materials and construction methods of cast-in-place wallboard structure can be divided into cast-in-place concrete for internal and external walls, cast-in-place concrete for horizontal walls and cast-in-place concrete for internal and vertical walls. The external wall adopts precast large plate (internal cast-in-place and external hanging) or brick and block (internal cast-in-place and external masonry for short). The cast-in-place wall can be constructed by setting formwork (large formwork, combined formwork and tunnel formwork) or by slipform and lifting formwork. Cast in situ concrete slab, prefabricated strip slab or integral slab shall be adopted for the floor slab, and the floor slab shall be made into continuous slab to improve the integrity of the house. In order to ensure the good combination of internal and external walls, the external wall should be built first and then the concrete internal wall should be poured.

Internal force calculation of wallboard: under vertical load, the internal force is distributed according to the area ratio of vertical and horizontal wall sections. When the transverse horizontal force is applied, a part of the outer longitudinal wall can be used as the effective flange of the transverse wall, the calculation figure can be simplified as a frame, each wall limb of the transverse wall can be used as a frame column, the coupling beam of the transverse wall can be used as a frame beam, and the floor slab can be used as an articulated link. When the longitudinal horizontal force is applied, the transverse wall takes part in the work, and the structure along the longitudinal direction is composed of the longitudinal wall and the transverse wall. The calculation figure can be simplified as a composite frame composed of the inner and outer walls, the coupling beam of the outer longitudinal wall is used as the frame beam, and the wall limb of the longitudinal wall and the transverse wall constitute the frame column. If the internal and external wall materials are different, the thickness of the external wall should be converted according to the ratio of the elastic modulus of the external and internal wall materials.