JPS62268401A - Semi-rigid paving construction method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a semi-rigid pavement construction method that significantly improves the efficiency of the injection and construction of cement paste or mortar that is injected into the voids of an open-grained asphalt concrete layer. be.

[Conventional technology]

Conventionally, there have been asphalt pavements and concrete pavements, each of which had its advantages and disadvantages, so recently semi-rigid pavements that have the characteristics of both have been applied by fire (Patent Publication No. 55-45921).

Generally, in the semi-rigid pavement method, a porous bituminous mixture consisting of open aggregate and asphalt is heated in advance, spread evenly on the pavement base, compacted to a predetermined thickness, finished, and then mixed with open aggregate and asphalt. After the open-grained asphalt concrete layer is left to cool to below a specified temperature, cement paste or mortar made by kneading cement and water is infiltrated into the voids of the open-grained asphalt concrete by force and vibration, or the top surface is coated with a vibrating roller. Semi-rigid pavement was obtained by injecting and penetrating the cement paste or mortar into the voids of asphalt concrete (Japanese Patent Laid-Open No. 59-17).
0303, JP-A-59-195905).

[Problems to be solved by the invention] 'Can all the voids in the open-grained asphalt concrete layer be removed using the conventional method?
In order to fill the open-grained asphalt concrete layer with cement paste or mortar, the open-grained asphalt concrete layer must be kept at room temperature because if the open-grained asphalt concrete is hot, the cement paste or mortar added will lose its fluidity in a few seconds and become impossible to pour. I had to let it cool until then. Moreover, the penetration thickness of cement paste or solutar into open-grained asphalt concrete is 5c! The general construction thickness is about 10 m't, and to complete the construction, it has to be divided into two parts, which not only takes a huge amount of time, but also requires a lot of time between the two layers. A boundary arises,
This had the disadvantage of reducing the durability of the paving slab.

[Purpose of the invention]

The object of the present invention is to solve such conventional problems and to provide a method that allows construction of asphalt concrete to the pavement base at once even when the open-grained asphalt concrete is hot.

[Means for solving problems]

As a result of intensive research into cement paste or mortar that does not lose fluidity even at high temperatures and has good permeability, the present inventors found that cement paste or mortar containing oxycarboxylic acid and/or its salt, inorganic carbonate and/or Alternatively, they found that it is sufficient to make inorganic bicarbonate exist, and completed the present invention.

The present invention relates to a semi-rigid pavement construction method in which a pavement slab is formed by pouring cement paste or mortar into the voids after pouring an open-grain asphalt concrete layer on a pavement base, and in which the cement paste or mortar contains: This is a semi-rigid pavement construction method characterized by the total presence of oxycarboxylic acid and/or its salt, and inorganic carbonate and/or inorganic bicarbonate.

The present invention will be explained in detail below.

In the present invention, the open-grain asphalt concrete layer (hereinafter referred to as inter-grain asphalt concrete) has a maximum particle size of 16 to 20
mm open grain size aggregate as asphalt (petroleum asphalt for paving) t3 to 6% by weight is blended and heated to 100 to 200℃.
It is spread evenly over the entire paved base of open-grained Ascon that has been heated and mixed, and is rolled to a predetermined thickness with a roller or the like so that the porosity is 20% to -60%. It is not limited.

The cement used for the cement paste or mortar (hereinafter referred to as cement milk) injected into the open-grained ascon is Portland cement specified in JI8R5210, or a mixed cement made by mixing these with silica ζ fly ash, granulated blast furnace slag, etc. Possible. Other admixtures and admixtures such as rapid hardening materials, expansion materials, high-strength materials, shrinkage reducing agents, or high fluidizing agents can be used in combination with the above-mentioned Portland cement or mixed cement. From this point of view, it is preferable to use a rapid hardening cement containing a calcium haloaluminate and an inorganic sulfate.

Cement paste made by kneading these with water, or cement mortar made by completely mixing these with aggregate, which allows the pouring of open-grained ascon to be carried out smoothly, is suitable. Prepackaged concrete pouring mortar test method)
Those having a consistency corresponding to 9 to 13 seconds are preferred.

Examples of oxycarboxylic acids and salts thereof to be added to cement milk, which are a feature of the present invention, include gluconic acid, citric acid, or tartaric acid, or their sodium salts;
Potassium salts, ammonium salts, etc. are mentioned, and these are used in an amount of 1a or more.

Examples of the inorganic carbonates and inorganic bicarbonates include their sodium salts, potassium salts, ammonium salts, and the like.

Oxycarboxylic acid and/or its salt and inorganic carbonate and/or
Or, the ratio of inorganic bicarbonate is 10 to 50 Yu in the former, and 90 to 50 in the latter! - 俤 is preferred.

The appropriate amount of these mixed substances to be added to the cement milk is 0.2 to 6% by weight relative to the cement, preferably 0.6 to 2N.

The method of adding it is not particularly limited, but there are methods of adding it by dissolving it in kneading water in advance, and adding it to cement powder.

It is better to use it afterward.

Furthermore, it is an effective means to use a dispersant to increase the permeability of cement paste or mortar, and to use latex, emulsion, water-soluble polymeric substances, etc. to completely prevent the occurrence of surface cracks.

When injecting and penetrating the cement milk obtained in this way into a fully open size ascon, pour it when the surface temperature of the open size ascon has cooled to below 100°C, preferably below 8Cr'C, and use a vibrating roller or diaphragm to By infiltrating it, you can reach your goal.

〔Example〕

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 For the open-grained aggregate shown in Table 1, asphalt for paving)
A mixture of 3.5 weight i% and heated and mixed at 150°C was spread on the pavement base, with a thickness of 10 m and a porosity of 25.
% open particle size ascon was obtained. The temperature of open grain ascon is 8
At 0°C, all of the oxycarboxylic acids and inorganic carbonates shown in Table 2 are dissolved in the kneading water, mixed into ordinary cement, and the consistency is within the range of 9 to 12 seconds in P funnel flow time. The cement was poured into the concrete using a diaphragm, and the mixture was injected and permeated using a vibrating plate.

After 7 days of age, the pavement slabs were cored and the entire penetration distance of cement milk was observed. Similarly, after 7 days of age, the paving slab was cut into 4×4×16 pieces, and the bending strength was completely measured based on JIS R5201 "Physical Test Methods for Cement."

The materials used are as follows.

Cement: Ordinary Portland cement Aggregate: Open-grained aggregate Oxycarboxylic acid (salt), inorganic carbonate, inorganic bicarbonate:
First-class reagent.

As is clear from Table 2, Examples (Tests/161-7
) compared to the ratio example (test/Mero 8 to 10), the cement milk had sufficiently penetrated into the open size ascon, and the bending strength also showed a large value.

Example 2 0.2 M part of citric acid as oxycarboxylic acid and its salt was added to 100 parts by weight of quick-setting cement made by blending 15 layers of calcium aluminate quick-setting inorganic powder containing 44% by weight of CaO into ordinary Portland cement. A test was conducted in the same manner as in Example 1, using 0.1 part by weight of sodium gluconate and 0.7 part by weight of potassium carbonate as the inorganic carbonate, and setting the flow time of the cement milk through the P funnel to 9.8 seconds.

As a result, the cement paste hardened within an hour after pouring.
It was used as a road after 6 hours. After 7 days, we performed coring and investigated the penetration distance of cement milk, and found that it penetrated into the pavement by 10cIn! : It has been penetrated and solidified, and the bending strength is 57.
The asphalt concrete layer was in good condition, with an average hardness of 1/cm”f.

〔Effect of the invention〕

When the cement milk according to the present invention is heated at 100°C or less, it does not lose its fluidity even when it is still hot, and has good permeability. It is possible to perform construction up to the lower part at one time, and the construction time can be significantly shortened.

Claims (1)

[Claims] In a semi-rigid pavement construction method in which a pavement slab is formed by pouring cement paste or mortar into the voids after pouring an open-grained asphalt concrete layer on a pavement base, the cement paste or mortar is mixed with oxycarboxylic acid and A semi-rigid pavement construction method characterized by the presence of an inorganic carbonate and/or an inorganic bicarbonate and/or a salt thereof.