SU958626A1 - Wooden bar prestraining method - Google Patents

Description

(54) METHOD OF PRELIMINARY VOLTAGE OF WOODEN BAR

one

The invention relates to construction and is intended to reinforce glued wooden beams, girders, and other long elements.

A known method of prestressing a wooden bar involves inserting the reinforcement into the sawn timber, tensioning the reinforcement with jacks placed outside the beam, pouring the kerf with reinforcement with epoxy glue and subsequent tempering the reinforcement after curing the epoxy adhesive 1.

The disadvantages of this method are the high labor input for fixing the reinforcement and the complexity of the tooling, the breakage of the stressed reinforcement and the lack of guaranteed safety of workers, is

The closest technical solution to the present invention is a method of prestressing a timber bar, including a prestress Q of a bar by bending to the opposite bend, reinforcing the bar with a high strength wire laid in the cuts of the bar and pouring the cuts with reinforcement with a curing polymer composition 2.

2

The disadvantage of this method is the complexity of the work due to sophisticated technological equipment designed to create a prestressing beam by bending upward.

The aim of the invention is to simplify production.

This goal is achieved in that according to the method of prestressing a wooden bar, which includes placing the reinforcement into the saw blades, pouring the cuts with a hardened polymer composition, before the reinforcement is laid, the bar is compressed by an axial load applied to its ends, and after curing the polymer composition, the load is removed.

In addition, in order to give the bar a building lift, a load is applied to the ends of the bar with an eccentricity.

The drawing shows a wooden bar in the process of stress.

Wood beam 1 is supported with one end through the centering gasket 2 into the stop 3. Between the second end of the beam and the centering gasket 4, and the foot 3, a jack 5 is installed.

The beam is compressed along the axis, after which the reinforcement 7 is laid in the cuts 6.

The prop with reinforcement is poured with a curable polymer composition and after curing it is relieved.

In order to impart a construction lift to the bar, the gaskets 2 and 4 are installed with an offset from the center of the body of the beam ends, in the direction opposite to the bend.

The amount of bar compression is determined by calculation, depending on the required amount of prestressing wood.

The economic efficiency of the used prestressing device is determined by the reduction of labor costs in production, the use of simple equipment, a decrease in reject rates in the process of making structures.

Claims (2)

1. A method of prestressing a wooden bar, including laying S L,.; the reinforcement into the sawn timber and the filling of the kerfs with a curable polymer composition, characterized in that, in order to simplify production, before the reinforcement is laid, the timber is compressed by an axial load applied to its ends, and after the polymer composition is cured, the load is removed. 2. A method according to claim 1, characterized in that, in order to impart a construction hoist to a bar, a load is applied to the ends of a bar with an eccentricity. Sources of information taken into account in the examination 1.Shevchuk V.S., Frolov N.P. Strength and deformability of pre-stressed glued wooden beams with fiberglass reinforcement .- "Construction and architecture of Belarus, No. 4, -1975, p. AND. 2. Kovalchuk LM. Pasting of wood materials with plastics and metals. M., “Forest industry, 1968, p. 28. / x // vvvvv / v / v