JPH0227385B2 - TOGAIBOSHOME KOMIKARAASHISUIABURA - Google Patents

Description

[Detailed Description of the Invention] The present invention prevents inverted T-bolts from rusting by filling the embedded collars of PC sleepers, track slabs, etc., and even when rainwater enters and freezes over time, the To provide a water-stop oil for an embedded collar for preventing frost damage, which prevents cracks from forming in concrete around the embedded collar.

Conventionally, inverted T-bolts are used to attach rails and tie plates to PC sleepers and track slabs of railways, but inverted T-bolts are used to attach plastic anchor bodies that are pre-buried in PC sleepers and track slabs. In other words, it adopts a structure that is fastened to the embedded collar. In this case, in order to prevent the inverted T-bolt from rusting, the embedded collar is filled with grease as a waterproof oil. However, over time, rainwater enters the embedded collar, and this intruded rainwater freezes in cold regions or during cold seasons, and as a result, the internal pressure of the embedded collar increases. As a result, the embedded collar deforms and at the same time cracks occur in the concrete where the embedded collar is embedded, which causes
The PC sleepers and orbital slabs have suffered fatal damage, namely frost damage.

The present invention was made in order to eliminate the drawbacks of the conventional water stop oil as described above, and embodiments of the present invention will be described in detail below.

The present invention uses foamed plastic beads made of styrene, a thermoreversible resin whose surface is coated with powders such as inorganic iron sand and silica sand, and whose specific gravity is adjusted to be equivalent to that of the water-repellent grease. ). Incidentally, as the above-mentioned foamed plastic beads, MY Pole manufactured by Mitsubishi Yuka KK is known as a commercially available product. The water stop oil of the present invention is a mixture of grease and expanded polystyrene beads, and the pressure acting on it, that is, the pressure-relieving effect on the external pressure caused by the freezing of moisture that has entered the embedded collar, is determined by the blending ratio of expanded polystyrene beads and the moisture content. If the external pressure conditions are the same, the greater the blending ratio of beads with large porosity and gas content, the greater the pressure relief effect and the lower the thermal conductivity as a water stop oil. This is obvious from a mechanical and thermal engineering point of view. On the other hand, if the blending ratio of foamed beads is excessive, the waterproof and antirust performance, which is the function of a water stop oil, will be degraded due to moisture and water absorption in the beads or the voids between the beads. That is, there is a practically appropriate range for the blending ratio of beads.

The present invention will be explained below with reference to Examples.

A water-stopping oil was prototyped by applying iron sand to grease heated to 50°C and mixing and kneading it with a stirring rod while dropping polystyrene foam beads with a diameter of 1 to 2 mm adjusted to the specific gravity of the grease.Grease 100 We prototyped water stop oils with mixing ratios of 5, 10, 20, 30, 40, 60, 80, and 100 in which the apparent capacity of the grease, including the voids between the beads, was 5, 10, 20, 30, 40, 60, 80, and 100. was applied to a see-through glass container modeled after an embedded collar, and the dispersibility of the beads in water-stopping oil was tested, especially around the bolts. As a result, when the bead compounding ratio is 40 volumes or more, there are parts where the beads form blocks and cannot be dispersed independently, and it is also observed that there is a large amount of beads attached to the bolts. It is recognized that the mixing ratio of expanded polystyrene beads is limited to 35 volumes in order to ensure the dispersion of beads and the water stop oil beads to relieve pressure and strengthen insulation. We prototyped water stop oils with the same Styrofoam beads with a volume ratio of 0, that is, conventional water stop oil (grease), 10, 20, and 30, and filled these water stop oils into embedded collars of track slabs in cold regions. However, after installing the inverted T-bolts, we tracked the state of frost damage and found that cracks had appeared in the concrete around the embedded collar when using conventional water stop oil (grease), but with the water stop oil containing foamed beads according to the present invention, cracks appeared. , despite the fact that rainwater remains inside the embedded collar at all compounding ratios.
It was confirmed that there were no cracks in the concrete due to swelling caused by freezing. This means that even if rainwater that has entered the water stop oil freezes, the freezing swelling force is alleviated by the deformation of the foam beads that are kneaded and blended into the water stop oil, and the foam beads provide thermal conductivity. is lower, that is, temperature sensitivity is improved due to insulation properties,
This is because rapid cooling is prevented.
Foamed beads can also be used as bulking material and have the effect of reducing the need for water repellent materials such as grease. Furthermore, the embedded collar water-stop oil for frost damage prevention of the present invention has a structure in which a water-repellent material is filled in the gaps between particles of foamed beads, and the fluidity of the water-repellent material when the temperature rises in summer is lower than that of conventional products. One of its major advantages is that it does not run off from the embedded collar and stain the surface of PC sleepers and track slabs, unlike conventional water stop oil.

Examples of the present invention include beads obtained by foaming styrene, a thermoreversible resin, and iron sand, an inorganic substance, as a powder to be applied to adjust the specific gravity to the same level as grease. Although the effects of the present invention have been illustrated, there are many foamed plastic beads, apart from their economic efficiency, such as polyurethane, polypropylene, polyethylene, and nylon, which are already well known to have similar physical properties and behavior to styrene. It is technically clear that this thermoreversible resin can be utilized. In addition, iron sand, which is used to adjust the specific gravity, is an inorganic powder, and powders that are similar or common to iron sand include inorganic substances such as silica sand, minerals, ceramics, and cement, and these powders are used to adjust the specific gravity of foam beads. What can be done is technically obvious. Therefore, the present invention is widely applicable in terms of material resources and provides a meaningful technology.

Claims (1)

[Claims] 1. A frost damage prevention embedding characterized in that beads made of thermoreversible foamed plastic such as styrene, whose surface is coated with inorganic powder such as iron sand and whose specific gravity is adjusted to the same density as the grease, are blended with the grease. Colored waterproof oil.