JPH06293549A - Grout mortar composition - Google Patents

Abstract

PURPOSE:To improve flowability, non-separability of the component materials, compression strength and bond strength of a grout mortar composition by using cement, a superfine powder, an expansive admixture, a high performance water reducing agent and heavy-weight aggregate as the components of the composition. CONSTITUTION:The cement (A) such as various kinds of portland cement, various kinds of blended cement 3 to 40 pts.wt. of the superfine powder (B) which is not easily soluble in water and has <=1mum average particle size such as silica dust (fumed silica), 15 pts.wt. of the expansive admixture (C) such as a calcium sulfonate based or quick lime based expansive admixture 0.1 to 5 pts.wt. of the high performance water reducing agent (D) consisting essentially of a surface active agent, 50 to 250 pts.wt. of the nearly spherical heavy-weight aggregate (E) having >=3.0 specific gravity and <=3mm grain size such as iron grains (7 to 8 specific gravity), and 20 to 35 pts.wt. of water, based on 100 pts.wt. of the total amount of binders consisting of the component (A), (B) and (C) are mixed with each other. The mixing is performed by using a mixer or a premix type mixing method, in which the respective component materials are dry-blended together and thereafter water is added to the dry-blend, or by dissolving the component (D) into water to be mixed and then mixing the resulting solution with the other component materials.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a grout mortar composition used in the field of civil engineering and construction. The mortar in the present invention is a generic term for mortar or concrete.

[0002]

[Prior art and its problems] In civil engineering and construction work, construction work in mines, etc., fine voids in concrete structures, voids between the back of tunnel linings and the ground, voids in rebar sleeves, or PC Grouting work is being carried out by filling mortar and cement paste in the gaps between the steel sheath and PC steel, and various grout materials have been developed and put to practical use in a wide range.

Further, in recent years, as the quality of concrete as a structure has become higher in performance and quality, and the structure itself has become more complicated, the applications and performance required for grout materials have become more diverse and sophisticated. .

Grout materials include PC grout, grout for pre-packed concrete, dam joint grout, backfill grout for tunnels and shields, precast grout, structure repair / reinforcement injection grout, rebar joint grout, under bridge support. In addition to those that have been conventionally useful, such as grouts, under-base grouting, under-slab grouting, and under-container grouts for nuclear power plants,
In recent years, cable-stayed bridge diagonal grouts, steel joint grouts,
A wide variety of grout materials are also used in new fields such as grouts for RM structures, grouts under paving, ground anchors, and storage pits.

Among the above-mentioned grout materials, the reinforced joint grout joins precast reinforced concrete members on site for the purpose of improving the construction materials and increasing the height of the building due to progress and labor saving of construction work due to lack of skilled workers. In the method of construction, a method of using a sleeve for joints and filling the voids with a cement-based non-shrink grout material as a grout material is generally used (interim report of the quality evaluation research committee of the filler, 1992.12).
Published by Japan Concrete Institute).

[0006] However, the cement-based non-shrink grout has a compressive strength of about 700 kgf / cm ² and a small expansion amount after hardening, and the adhesive force between the filled grout and the deformed rebar or the joint sleeve is increased. However, there was a problem that they could not fulfill their role as reliable joints.

The present inventor has conducted various studies to solve the above-mentioned problems, and as a result, by using a specific material,
For example, the present invention has been completed based on the finding that it is easy to fill the void portion of the joint sleeve of the deformed rebar for joining reinforced concrete members, and that high compressive strength and high adhesive strength can be obtained after curing. .

[0008]

That is, the present invention is a grout mortar composition containing cement, ultrafine powder, an expanding material, a high-performance water reducing agent, and a heavy aggregate.

The present invention will be described in detail below.

As the cement according to the present invention, various kinds of portland cement such as normal, early strength, and ultra-early strength are generally used. Various kinds of fly ash, blast furnace slag, or silica are mixed with these portland cements. Mixed cement, moderate heat Portland cement, and
It is also possible to use low heat-generating cement for mass concrete.

[0011] In addition, for example, such as "Nippon Steel Colloid" and "Nippon Steel Super Fine" manufactured by Nippon Steel Cement Co., Ltd., fine cement obtained by making these cements into fine powder, and further, blast furnace slag and an alkali stimulant. Mixtures of can also be used as the cement of the present invention.

The ultrafine powder according to the present invention is a powder having an average particle diameter of 1 μm or less, and there is no particular limitation on the components, but those which are easily soluble in water are not suitable. Specifically, silica, silicon alloys, or silica dust (silica fume) by-produced when manufacturing zirconia, silica dust, fly ash, calcium carbonate, silica gel, opal silica, titanium oxide, and ammonium oxide. It is also possible to use, for example, and of these, it is preferable to use silica dust (silica fume) or siliceous dust.

The amount of the ultrafine powder used is preferably 3 to 40 parts by weight with respect to 100 parts by weight of the binder composed of cement, ultrafine powder and expansive material. From the viewpoint of fluidity and moldability of the kneaded product, 5
-30 parts by weight is more preferred. If it exceeds 40 parts by weight, it will be difficult to knead the binder, and strength development will be insufficient, and if it is less than 3 parts by weight, strength development will tend to be insufficient.

The expansive material according to the present invention is effective in improving the adhesion to the joint sleeve and the deformed reinforcing bar, and improving the adhesion by reducing the shrinkage.

As the expansive material, for example, calcium sulphoaluminate type, quick lime type such as calcined CaO, gypsum type, and quick lime-gypsum type can be used.

The amount of the expanding material used is preferably 15 parts by weight or less, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the binder. If it exceeds 15 parts by weight, the amount of expansion tends to be excessive.

The high-performance water-reducing agent according to the present invention has a large dispersibility without delay of setting or excessive air entrainment even when added in a large amount to cement, and a surfactant can be used. Specific examples include salts of melamine sulfonic acid formaldehyde condensate, salts of naphthalene sulfonic acid formaldehyde condensate, high molecular weight lignin sulfonate, and polycarboxylate.

The amount of the high-performance water reducing agent used is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the binder. If it is less than 0.1 part by weight, the fluidity of the grout mortar will be poor, and if it is used in excess of 5 parts by weight, the grout mortar will have a high air entrainment property, and material separation will tend to occur.

The heavy aggregate according to the present invention is not particularly limited as long as the specific gravity is 3.0 or more.
(Specific gravity 7-8), magnetite (specific gravity 4.5-5.2), sand iron (specific gravity 4-
5), hematite (specific gravity 4-5.3), limonite (specific gravity 2.7-4), barite (barite, specific gravity 4-4.7), converter-furnace slag (specific gravity 2.
7-3.5), steel fiber (specific gravity 7-8) and the like can be used.

The shape of the heavy aggregate is preferably close to a sphere from the viewpoint of fluidity and workability, and the particle size thereof is preferably 3 mm or less, more preferably 1 to 2 mm.

The amount of the heavy aggregate used is preferably 50 to 250 parts by weight with respect to 100 parts by weight of the binder. If it exceeds 250 parts by weight, the material separation of grout mortar becomes severe, and if it is less than 50 parts by weight, the amount of cement in the grout mortar increases,
This is not preferable because the heat generation increases.

The amount of water used in the present invention is preferably 20 to 35 parts by weight with respect to 100 parts by weight of the binder. If it is less than 20 parts by weight, the fluidity tends to decrease, and if it exceeds 35 parts by weight, the strength tends to decrease.

In the present invention, the method of mixing the respective materials is not particularly limited, and an ordinary mixer can be used. Also, dry blend each material,
It is also possible to use a premix type of mixing with water later, and a method of dissolving the high-performance water reducing agent in kneading water and mixing is also sufficiently possible.

[0024]

The present invention will be further described below based on examples.

Example 1 A mortar was prepared by adding 2 parts by weight of a high-performance water reducing agent to the formulations shown in Table 1 other than Experiment No. 1-1 to prepare a mortar.
The compressive strength of the mortar and the adhesive strength of the reinforcing bars were measured on the day. The results are also shown in Table 1. The test methods and materials used are as follows.

<Test method> Compressive strength: Measured according to JIS A 1108. Create a φ5 × 10 cm cylinder specimen, remove it from the mold one day later, and age 20 until 20 days
It was cured in water at ℃. Adhesion strength: The adhesion strength of the round steel of φ19 cm with a 16 cm embedded depth to the reinforcing bar during drawing was determined. The curing was 20 ° C sealed curing.

<Materials used> Cement: Ordinary Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd. Ultra fine powder: Silica dust produced by Ferrosilicon manufactured by Nippon Heavy Chemical Industry Co., Ltd., average particle size 0.1μ Expanding material: Denka Kagaku Kogyo's trade name "CSA"# 20 ", main component calcium sulfaluminate High-performance water reducing agent: Denki Kagaku Kogyo Co., Ltd. trade name" FT-500 ", main component alkylnaphthalene sulfonic acid formaldehyde condensate salt Weight Aggregate: Nippon Magnetic Select Steel Co., Ltd. product Name `` NJ Sand '', specific gravity 3.
1 Water: Tap water

[0028]

[Table 1]

As is clear from Table 1, when the grout mortar composition of the present invention is used, the same fluidity as that of a normal cement-based non-shrink grout material can be obtained. For example, a joint of deformed rebar for joining precast reinforced concrete members. The voids of the sleeve were easily filled, and after curing, high compressive strength and high adhesive strength were obtained. Experiment No.1-12
, The heat of hydration of the cement was high due to the large amount of cement in the grout mortar.

[0030]

EFFECTS OF THE INVENTION When the expansive high-strength grout mortar of the present invention is used, such effects as excellent fluidity, no material separation, high compressive strength and high adhesive strength are exhibited. Therefore, it is possible to obtain a grout mortar having an excellent quality as the grout mortar to be filled in the void portion of the joint sleeve of the deformed rebar for joining precast reinforced concrete members.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area C04B 14:48) Z 2102-4G

Claims (1)

[Claims] 1. A grout mortar composition comprising cement, ultrafine powder, an expanding material, a high-performance water reducing agent, and a heavy aggregate.