Interlocking Blocks

Abstract

To provide an interlocking block excellent in abrasion resistance.SOLUTION: An interlocking block including a road surface forming layer composed of a cement composition containing cement, an aggregate, and water has a 5 mm sieve residue amount of the aggregate of 2 mass% or more and a ratio of the 5 mm sieve residue amount of the aggregate in 100 vol.% of the road surface forming layer of 2.0 to 80 vol.%. A fineness modulus of the aggregate is preferably from 3.08 to 8.25. Pavement using the interlocking block is constructed by installing the interlocking block in the area with which a movable body passing through on pavements comes in contact.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an interlocking block. [Background technology]

[0002] Currently, more than 80% of all interlocking blocks produced are used for paving sidewalks or plazas. Meanwhile, in recent years, the Japan Interlocking Block Pavement Association (JIPEA) has confirmed that straight interlocking blocks developed for roadway use can be applied to roads with traffic classifications of around N3. Patent Document 1 describes a surface layer material for interlocking blocks that has sufficient abrasion resistance even when used on roadways, and that is made from a hardened mixture containing at least cement, pozzolanic fine powder, aggregate with a particle size of 2 mm or less, water, and a water-reducing agent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-278651 Summary of the Invention [Problem to be solved by the invention]

[0004] When interlocking blocks are used on roadways with heavy traffic, the interlocking blocks need to have high abrasion resistance (wear resistance). An object of the present invention is to provide an interlocking block having excellent wear resistance. [Means for solving the problem]

[0005] As a result of intensive research into solving the above-mentioned problems, the inventors have discovered that the above-mentioned object can be achieved by an interlocking block that includes a road surface forming layer made of a cement composition containing cement, aggregate, and water, in which the 5mm sieve residue content of the aggregate is 2% by mass or more, and the proportion of the 5mm sieve residue content in 100% by volume of the road surface forming layer is 2.0 to 80% by volume, and have completed the present invention. That is, the present invention provides the following [1] to [3]. [1] An interlocking block comprising a road surface forming layer made of a cement composition containing cement, aggregate, and water, wherein the 5 mm sieve residue of the aggregate is 2 mass% or more, and the proportion of the 5 mm sieve residue in 100 volume% of the road surface forming layer is 2.0 to 80 volume%. [2] The interlocking block according to [1], wherein the aggregate has a coarse particle ratio of 3.08 to 8.25. [3] A pavement using the interlocking blocks described in [1] or [2], wherein the interlocking blocks are arranged in an area where the pavement comes into contact with a moving object passing over the pavement. [Effects of the Invention]

[0006] The interlocking block of the present invention has excellent wear resistance. DETAILED DESCRIPTION OF THE INVENTION

[0007] The interlocking block of the present invention is an interlocking block comprising a road surface forming layer consisting of a cement composition containing cement, aggregate, and water, wherein the 5 mm sieve residue of the aggregate is 2 mass% or more, and the proportion of the 5 mm sieve residue in 100 volume% of the road surface forming layer is 2.0 to 80 volume%. A detailed explanation is provided below. The cement contained in the cement composition is not particularly limited, and examples thereof include various Portland cements such as ordinary Portland cement, high-early-strength Portland cement, moderate-heat Portland cement, and low-heat Portland cement, mixed cements such as blast-furnace cement and fly ash cement, and ecocement, etc. These may be used alone or in combination of two or more.

[0008] The 5 mm sieve residue amount of the aggregate contained in the cement composition is 2% by mass or more. From the viewpoint of improving abrasion resistance, the 5 mm sieve residue amount is 2% by mass or more, preferably 3% by mass or more, more preferably 4% by mass or more, even more preferably 8% by mass or more, even more preferably 15% by mass or more, even more preferably 30% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more.

[0009] From the viewpoint of improving the abrasion resistance and strength of the interlocking blocks, the aggregate has a particle size ratio of preferably 3.08 to 8.25, more preferably 3.20 to 7.00, even more preferably 3.40 to 6.00, even more preferably 3.60 to 5.70, and particularly preferably 3.80 to 4.20. If the particle size ratio is 3.08 or more, the abrasion resistance of the interlocking blocks can be further improved. If the particle size ratio is 8.25 or less, the strength (e.g., bending strength) of the interlocking blocks can be increased, and the durability of the interlocking blocks can be further improved. The quality evaluation criteria for interlocking blocks can be broadly divided into two types, based on standard values ​​or safety. For example, according to the "Interlocking Block Pavement Design and Construction Guidelines" issued by the Interlocking Block Pavement Technology Association, the standard value for the bending strength of interlocking blocks is 5.0 N / mm 2 If the coarse grain ratio is 8.25 or less, the bending strength of the interlocking block is set to the specified value (5.0 N / mm 2 The above conditions can be satisfied. The actual bending strength of the interlocking block is approximately 6.0N / mm, taking into account the safety factor. 2 If the coarse grain ratio is 7.00 or less, the bending strength of the interlocking block is preferably 6.0 N / mm 2 It can be more than that. In addition, the coarseness ratio of aggregate can be measured in accordance with "JIS A 1102:2014 (Test method for sieving aggregate)".

[0010] The aggregate may be fine aggregate only, coarse aggregate only, or a combination of fine and coarse aggregates. Natural aggregate, artificial aggregate, or recycled aggregate may also be used. The fine aggregate is not particularly limited, and examples thereof include river sand, mountain sand, land sand, sea sand, crushed sand, silica sand, slag fine aggregate, lightweight fine aggregate, etc. These may be used alone or in combination of two or more. The coarse aggregate is not particularly limited, and examples thereof include river gravel, mountain gravel, land gravel, sea gravel, crushed stone, slag coarse aggregate, lightweight coarse aggregate, etc. These may be used alone or in combination of two or more.

[0011] The amount of aggregate mixed in the cement composition (the total amount when fine aggregate and coarse aggregate are used in combination) is not particularly limited, and may be a general amount mixed in mortar or concrete. For example, the amount of aggregate mixed is preferably 50 to 800 parts by mass, more preferably 100 to 700 parts by mass, and particularly preferably 150 to 600 parts by mass, relative to 100 parts by mass of cement. The amount of fine aggregate mixed is preferably 10 to 700 parts by mass, more preferably 20 to 500 parts by mass, more preferably 50 to 400 parts by mass, and particularly preferably 100 to 300 parts by mass, per 100 parts by mass of cement. When coarse aggregate is used, the fine aggregate ratio is preferably 0 to 80%, more preferably 3 to 60%, and particularly preferably 40 to 60%. If the fine aggregate ratio is within the above range, the ease of molding of the cement composition and the filling ratio are improved.

[0012] The water contained in the cement composition is not particularly limited, and examples thereof include tap water and sludge water. The amount of water to be added is such that the water-cement ratio is preferably 10 to 60%, more preferably 15 to 50%, even more preferably 18 to 40%, and particularly preferably 20 to 35%. If the ratio is 10% or more, the bending strength of the interlocking block can be increased. If the ratio is 60% or less, the wear resistance of the interlocking block can be increased. The "water-cement ratio" is the mass ratio of water to cement (water / cement) expressed as a percentage.

[0013] The cement composition may contain other materials as needed within the scope of the present invention, including various admixtures such as cement dispersants (water-reducing agents, air-entraining water-reducing agents, high-performance water-reducing agents, or high-performance air-entraining water-reducing agents), antifoaming agents, and shrinkage-reducing agents, as well as various admixtures such as fly ash, silica fume, and ground granulated blast furnace slag. In this specification, the cement composition includes both a fluid form before hardening and a form after hardening.

[0014] The interlocking block of the present invention includes a road surface formation layer made of the above-mentioned cement composition. Here, the road surface formation layer refers to the layer that forms the upper surface of the interlocking block (the surface that comes into contact with vehicle tires, etc.). The interlocking blocks may consist only of a road surface forming layer (all of the interlocking blocks are made of the above-mentioned cement composition), or may include a road surface forming layer and a base layer (the layer that forms the underside of the interlocking blocks). The base layer may be made of mortar, concrete, or the like that is generally used as an interlocking block.

[0015] The proportion of aggregate remaining on a 5 mm sieve in 100% by volume of the road surface forming layer is 2.0 to 80% by volume, preferably 5.0 to 80% by volume, more preferably 10.0 to 80% by volume, even more preferably 20 to 75% by volume, and particularly preferably 30 to 75% by volume. If this proportion is less than 2.0% by volume, the abrasion resistance of the interlocking blocks will decrease. If this proportion exceeds 80% by volume, the strength (e.g., bending strength) of the interlocking blocks may decrease.

[0016] The interlocking block of the present invention can be produced by a conventional method for producing an interlocking block, for example, by mixing cement, aggregate, and water, molding the resulting mixture using an interlocking block molding machine using a high-vibration, pressurized, and immediate demolding method, and then curing the resulting molded product in air. That is, the interlocking block of the present invention can be manufactured without using a special manufacturing method, and the wear resistance can be improved while maintaining the productivity in manufacturing.

[0017] The interlocking blocks of the present invention have excellent abrasion resistance and are therefore suitable for paving sidewalks, plazas, roadways, and the like. The interlocking blocks of the present invention may be used in all areas of the pavement, but from the viewpoint of reducing the cost required for manufacturing the pavement, the interlocking blocks of the present invention may be disposed only in areas where the pavement comes into contact with moving objects passing over the pavement (for example, areas that come into contact with vehicle tires, etc.). In areas other than the areas where the moving objects come into contact, ordinary interlocking blocks, asphalt, concrete, etc. may be used. [Example]

[0018] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. [Materials used] (1) Cement: Ordinary Portland cement manufactured by Taiheiyo Cement Corporation (2) Fine aggregate A; Silica sand No. 5, surface dry density: 2.63g / cm 3 (3) Fine aggregate B: Medium sand, surface dry density: 2.64 g / cm 3 (4) Fine aggregate C; coarse sand, surface dry density: 2.65g / cm 3 (5) Fine aggregate D Crushed stone No. 7, surface dry density: 2.71 g / cm 3 (6) Coarse aggregate B: crushed stone No. 6, surface dry density: 2.63 g / cm 3 (7) Coarse aggregate C: crushed stone No. 4, surface dry density: 2.62 g / cm 3 (8) High-performance water reducer: Pozzolith Solutions, polycarboxylic acid ether type

[0019] [Production of aggregates 1 to 12] Fine aggregate A~ D , and coarse aggregate B ~C is the aggregate, fine aggregate A~ D and coarse aggregate B The aggregates 1 to 12 having the 5 mm sieve residue amount and coarse particle ratio shown in Table 1 were produced by mixing the materials in amounts in which the ratios of 1 to 1C were the same as those shown in Table 1. For aggregates 1 to 4, fine aggregate B (unclassified) was used in the amounts that would result in the mixing ratios shown in Table 1. For aggregates 9 to 11, fine aggregate B was classified to obtain (a) fine aggregate that passes through a 0.3 mm sieve, (b) fine aggregate that does not pass through a 0.3 mm sieve but passes through a 1.2 mm sieve, (c) fine aggregate that does not pass through a 0.3 mm sieve but passes through a 2.5 mm sieve, and (d) fine aggregate that does not pass through a 1.2 mm sieve but passes through a 2.5 mm sieve, and was used in the amounts that would result in the mixing ratios shown in Table 1.

[0020] [Table 1]

[0021] [Examples 1 to 7, Comparative Examples 1 to 5] The types and amounts of cement and aggregate shown in Table 2 were mixed with water in an amount that would give the water-cement ratio shown in Table 2, and the resulting mixture was molded using an interlocking block molding machine with high vibration pressure and immediate demolding. The resulting molded product was cured in air in a room at 20±2°C to produce interlocking blocks. The bending strength of the obtained interlocking blocks at 14 days of age was measured in accordance with "JIS A 5371:2016 (precast unreinforced concrete products)". Additionally, a labeling test of the interlocking blocks was conducted in accordance with the Japan Road Association Pavement Survey and Testing Methods Handbook B002, with spike chains attached to the tires. The labeling test was conducted in an environment of 20°C, and the wear depth of 30 interlocking blocks was measured at 10mm intervals using a vernier caliper, with the average value being taken as the average wear depth. The average wear depth was also measured after 4,000, 8,000, 10,000, 20,000, and 30,000 rotations. The results are shown in Table 3. In Table 3, the symbol "-" next to the average wear depth indicates that the measurement was discontinued because the average wear depth exceeded 20 mm.

[0022] [Table 2]

[0023] [Table 3]

[0024] From Table 3, when comparing Examples 1 to 7 and Comparative Examples 1 to 5, it can be seen that the average wear depths of Examples 1 to 7 (5 mm sieve residue: 3 to 100 mass%) (after 4,000 rotations: 1.0 to 2.2 mm, after 8,000 rotations: 1.9 to 4.2 mm, after 10,000 rotations: 2.2 to 7.1 mm, after 20,000 rotations: 2.4 to 10.2 mm, after 30,000 rotations: 2.5 to 10.8 mm) are smaller than the average wear depths of Comparative Examples 1 to 5 (5 mm sieve residue: 0 mass%) (after 4,000 rotations: 4.1 to 10.6 mm, after 8,000 rotations: 7.2 to 11.3 mm, after 10,000 rotations: 8.6 mm or more, after 20,000 rotations: 11.2 mm or more, after 30,000 rotations: 12.4 mm or more).

Claims

1. An interlocking block including a road surface forming layer made of a cement composition including cement, aggregate, and water, The aggregate has a 5 mm sieve residue of 51% by mass or more and a coarse particle ratio of 5.51 to 8.25, The proportion of the 5 mm sieve residue in 100% by volume of the road surface forming layer is 43.6 to 80% by volume, The amount of the aggregate mixed is 522 to 600 parts by mass per 100 parts by mass of cement, The water-cement ratio is 15 to 20%; An interlocking block characterized by having a fine aggregate ratio of 0 to 60%.

2. A pavement using the interlocking blocks according to claim 1, The pavement is formed by disposing the interlocking blocks in an area where the pavement comes into contact with a moving object passing over the pavement.

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