SU1740521A1 - Method of forming deformation seam in fresh-laid road bed concrete - Google Patents

Abstract

Use: road construction, making joints of cement-concrete pavement. SUMMARY OF THE INVENTION: A seam in a freshly laid cement-concrete coating is formed by an active former with a frequency of 30-60 strokes per minute with an amplitude of 1 / 5-1 / 3 the length of the active former, and the formation of a joint by a passive former is carried out by forward motion of the passive former to the full depth. In this case, the smoothing plate is moved along the seam at the same time with the former. As a result, the quality of the seam is improved and the complexity of its device is reduced. 2 Il. L cr

Description

The invention relates to the construction and can be used in the manufacture of joints cement concrete pavement.

The known method of the device profile of an expansion joint in freshly laid concrete with the use of embedded patterns. The method includes the following operations: cutting a slit using a vibro cut and simultaneously laying it into a concrete pair of paired bands (paired tape) for the period of the mobile state, pressing it against the walls of the slot with a template that is pulled between the strips. Filling the sand with the template of the weld cavity for setting the concrete , removing strips and removing sand from the joint cavity by blowing or in another way.

Closest to the invention is a method of arranging a profile of an expansion joint in freshly laid concrete, comprising the following operations: forming a cavity in concrete with a vibroplate, broadening its upper part with a former, introducing into the resulting cavity bulk material, such as sand, or wetting the walls with a liquid . In addition, a smoothing slab | With a slit oriented along the bei is placed on the surface of fresh concrete.

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When the cavity is formed in the concrete and the upper part is widened, the vibroplate and the former are moved in the slot of the slab.

The disadvantages of these methods are the low quality of the seam being arranged and the high labor intensity of their manufacture. Poor quality is caused by the fact that a vibroplate is used as the active forming agent. The vibration effect does not allow for a stable weld quality due to the effect of vibration on the initial structural strength of the concrete laid. Vibration leads to thinning of the concrete mix, disruption of structural bonds and uncontrolled movement of large aggregate particles, which often leads to wedging of the screed and the formation of a trap on the surface and edges of the seam. The greater complexity of the seam device is due to the presence of filling the cavity with loose material prevent closure of the walls and then removing it from the joint cavity, for example, blowing.

The aim of the invention is to improve the quality of the seam, as well as reduce the complexity of its manufacture.

This goal is ensured by the fact that, according to the method of forming a profile of an expansion joint in freshly laid concrete, the road surface includes placing a smoothing plate on the surface of freshly laid concrete with a slot oriented along the axis of the joint, followed by installing an active former in the slot of the active forming agent, the seam is formed by reciprocating the active forming unit with a frequency of 30-60 strokes per minute with an amplitude of 1 / 5-1 / 3 the length of the active forming component, and A seam with a passive former is carried out to the full depth, with the smoothing plate being moved along the seam simultaneously with the formers.

FIG. 1 shows the active Former; in fig. 2 - the seam after the passage of the active formant.

FIG. 1 and 2 show the seam 2 remaining after the passage of the active former 1 forward, the seam 3 remaining after the passage of the active formant backwards, the concrete mix, I-IV are the stages of the movement of the active shearer, and July 5th after the passage of the active form

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spinner, active molder in extreme position a, active jürm-. tel in a central position in the passive former 6, the seam 7 after the passage of the passive former. During the forward movement of the active former in the compacted concrete mix, plastering of the seam walls occurs,

Example. The concrete mixture was laid in the coating by the paver, and the mixture was prepared in a Rex concrete mixing plant.

Concrete mixture with a consumption of material per 1 m3, containing, kg: cement 389, sand 793, crushed stone 1171, water 140 l, PPF additives 0.008 and C-3 0, -6 masses of cement, had mobility at the place of installation 2 cm OK and volume air entrained within.

When a seam was made, a smoothing slab | With a slot oriented along the seam axis was placed on the surface of freshly laid concrete pavement. Then placed the active former in the slot smoothing pl-, you. A passive former was installed strictly in alignment with the active former.

Claims (1)

When moving the smoothing plate forward, reciprocating the active former formed a seam in the concrete, with the translational movement of the passive former made the final processing of the seam t to the full depth. The parameters of the operation of the active molder were: the frequency of $ Q moves per 1 minute, the amplitude of 75 mm with the length of the molder 300 mm. Invention Formula A method of forming a profile of a expansion joint in freshly laid pavement concrete, including placing a smoothing plate on the surface of freshly laid concrete with a slot oriented along the axis of the joint followed by installation in the slot of the active forming agent that, in order to improve the quality of the seam, as well as reduce the complexity of its manufacture, the seam is formed by reciprocating movement th formformer with a frequency of 30-60 strokes / min with ampli517 0521 This is 1/5 - 1/3 of the length of the active form of the former, with the iron being smoothed, and the formation of a seam, the passive slab is moved along the seam with a single-former for the entire depth of the molds, the bent translational motion of the passive at   about -9 00 Phie. one M0s7jt 0 & e wp # 0deem V. No. . ,  ABOUT . . Ov FIG. 2