JPS5851099B2 - Pre-cast concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses precast concrete beam members (hereinafter referred to as 20 members), which may be used alone or in combination, or partially include slabs (hereinafter referred to as 20 members), steel frame concrete girders, prefabricated reinforced concrete beams, and reinforced concrete beams (hereinafter referred to as frame beams). This relates to a construction method for assembling 20 members and girders for the purpose of integrally constructing the frame.

A construction method for assembling precast concrete members has already been proposed, which rationally combines precast concrete members such as large beams or small beams with reinforced concrete structural columns or large beams to achieve stress distribution according to the construction sequence.

The gist of this is to reduce the number of joints and to simplify the joints, but this is done by using steel columns or horizontal steel frames as supporting construction materials.

However, this invention uses temporary construction support materials and removes the support materials after the structural concrete has hardened.
An assembled frame construction method that rationally combines the stress distribution (bending moment) caused by the construction sequence of the frame girders and PC beams without using steel frames for the cross sections, columns, and girders. It is.

Therefore, the temporary support material can be used repeatedly, and there is no need to use structural materials that do not add to the cross-sectional stress, leading to savings in materials and construction costs.

Next, the present invention will be described with reference to FIGS.
At both ends, other PC members la and lb of the same structure are supported by temporary support members 4.4a at positions where they can be joined to each other, and the frame girder 2 is attached onto the center line A of each of the 20 members 1° 1a and 1b. The positions of the 20 members are determined in consideration of the provision of

Therefore, the girder 2 and slab 3 are constructed using concrete poured on site.

In the above, since the weight of the 40 member 1゜1a, lb and the on-site cast concrete slab is supported by the temporary support members 4 and 4a, a bending moment as shown in Fig. 4 is generated in the 20 member. And the center part is (+)
It can be seen that the bending moment is .

As the concrete poured on-site hardens, the slab and the frame girder are integrated, so if the temporary support material is removed, the structure will be in the so-called Yajirobei state with the frame girder in the center position, or depending on the structure, Both ends are fixed,
At the center position A of the 20 members, the bending moment is O1, or the opposite (-) bending moment occurs.

That is, it is determined by the joining state of the both end joints B of the 20 members.

Assuming that this joint B is completely joined (integral), both ends are fixed, and Ma=Mb.

That is, in the central portion A, the bending moment with respect to the fixed load (self-weight) of the slab and the 20 member 1 becomes 0.

Next, when the joint part B of each of the 20 members is made into a bottle-shaped joint, for example, by a steel frame joint method, the following results will be obtained.

In other words, it becomes possible to select the most rational distribution of stress by combining and considering the conditions of the 20 members during construction and the live load, and it is possible to design the most rational cross section of the 20 members.

In the above embodiment, the prestressing method was applied in the axial direction of the 20 members, and the intersecting small beam branches at intermediate positions were made of reinforced concrete. Cross beams can be effectively formed.

The slab can also incorporate precast panels and join them using conventional construction methods.

However, in small-scale cases, a reinforced concrete structure may be sufficient.

Next, in the embodiment shown in FIG. 3, a steel frame 5 is used in place of the reinforced concrete beam of the embodiment shown in FIG.

In this case, a slight gap is provided between the upper surface of the steel frame 5 and the lower surface of the 20 members 1, a moment is initially generated at the lower end at the center of the 20 members, and then mortar is grouted into the gap C. If it is filled with the same amount of water, the stress relationship as shown in FIG. 4 can be obtained similarly to the embodiment shown in FIG. 2.

In this case, it is necessary to connect the 20 members 1 and the steel girder 5 using the PC steel rods 6, but if steel reinforced concrete is used, there is no need for the connection using the steel rods.

Next, the embodiment shown in FIG. 5 is a case where the direction of the intersecting beam plates of the 20 members 7 is set at 45 degrees with respect to the direction of the frame girder, and the joining method is the same as in the previous embodiment.

8 in the figure is the column position.

That is, according to the present invention, the 20 members are temporarily installed and supported at or near the ends, and after the ends of each of the 20 members are joined to each other, a frame girder is provided at the center of the 20 members. , the 20 members and the frame girder are integrated by pouring concrete on-site, and a slab is also provided, and after the concrete hardens, the temporary support material is removed, so a stress-wise rational cross section of the 20 members is determined, This has the effect of saving structural materials and streamlining construction.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the arrangement of 20 members according to an embodiment of the present invention, Fig. 2 is a sectional view showing the relationship between the 20 members, the frame girder, and the slab, and Fig. 3 is a plan view showing the arrangement of 20 members according to an embodiment of the present invention. A cross-sectional view, FIG. 4 is a moment diagram of the 20 members before and after removal of the temporary support material, and FIG. 5 is a plan view showing the arrangement of the other 20 members. 1.1a, lb...20 members, 2...
Frame girder, 3...- Slab, 4,4a...-
Temporary construction support material, 5... Steel frame, 6... Steel bar, 7, 7a... 20 members, 8... Column position.

Claims (1)

[Claims] 1. A first step of supporting both ends or near both ends of each precast concrete small beam member in a predetermined state using temporary construction support materials, and a large beam placed in the center of the precast concrete small beam member. a second step of constructing a concrete slab and providing a two-body concrete slab with the precast concrete beam member, and a third step of removing the temporary support material in the first step after the integrated concrete slab has hardened. An assembly construction method for precast concrete small beam members and girders, which is characterized by joining. 2. A first step in which both ends or near both ends of each precast concrete beam member are supported in a predetermined state by temporary construction supports, and the mutually opposing ends are joined to the ends of other adjacent precast concrete beam members. , a large beam is constructed in the center of the precast concrete small beam member,
A second step of providing a concrete slab integrated with the precast concrete beam member and a third step of removing the temporary support material in the first step after the integrated concrete slab hardens are combined. This is a construction method for assembling precast concrete small beam members and large beams.