JPS5852944B2 - Cement admixture for grouting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cement admixture for grout containing a calcium sulfoaluminate type substance as a basic component.

Conventionally, 3CaO, 3A1203-CasO+ (hereinafter referred to as align), free gypsum (hereinafter referred to as F-CaSO
The basic component is calcium sulfoaluminate containing free lime (hereinafter referred to as F-CaO) and a small amount of an organic sizing agent, a foaming agent, a cement dispersant, and a cement quick-setting agent. A cement admixture for grouting is known from Japanese Patent No. 799240.

Grout made using this grout has high adhesive shear strength, can prevent breathing and subsidence, and is non-shrinkable, so it is used for fixing anchor bolts on bridges and the like, and for installing machine pedestals.

However, for example, chemical grouting can be used as grout for joint gaps between inner piers (steel pipe columns) and pile head cross beams or lower layer cross beams, long anchors for steel tower foundations, rock anchors, etc. without impairing the characteristics possessed by Japanese Patent No. 799240. There is a need for a grout that can introduce stress.

The present invention provides a cement admixture for grout that meets this need.

The gist is that calcium sulfoaluminate substances (
In a composition in which a small amount of an organic sizing agent, a foaming agent, a cement dispersant, and a cement quick-setting agent are present in the basic component (hereinafter referred to as the basic component), the composition of the basic component is 5 to 40% Align,
The remainder is made to coexist with F-CaS04 alone or with F-CaO, and in the case of coexistence, F-CaS04 is F-CaS04.
1.5 times the weight of O or more, and the particles of the basic component must be 88μ and or 149 to 250μ, or 44μ or less 20 to 80%, 88 to 149μ 20 to 80%
, 250μ or more and 20% or less, and if the total is less than 100, the cement admixture for grout is composed of particles of 44 to 88μ and/or 149 to 250μ.

The present invention will be explained in detail below.

In the present invention, the composition of the basic components is 5 to 40%
The reason why the remainder was made to coexist with FCa5O+ alone or with F-CaO is that if the amount of align is smaller than this, the amount of ettringite produced will be small, and if the amount is larger than this, the gypsum or lime content to produce ettringite will be As a result, if it coexists with cement, a large amount of calcium sulfoaluminate hydrate other than ettringite will be produced, or the gypsum or lime content in the cement will be rapidly consumed, causing the cement to deteriorate. This is because, in either case, it becomes impossible to introduce chemical prestress and prevent drying shrinkage.

In addition, in the present invention, in order to improve the water utilization reaction of the basic components and to speed up the production of ettringite, F-CaO may be allowed to coexist with the remaining F-CaSO; however, in this case, F-CaO is F- Specifically, F-CaS04 is less than 1.5% of F-CaO.
It is necessary to increase the weight by 5 times or more, preferably by 2 times or more.

The reason for this is that, as is well known, the presence of a large amount of F--CaO has an adverse effect on the setting and hardening of cement.

To produce clinker with this basic composition,
Raw materials such as quicklime, slaked lime, bauxite, diaspor, and various types of gypsum may be mixed stoichiometrically into the desired composition, sintered or melted at a temperature of about 1100 to 1400°C, and then cooled.

Next, the particle size of the basic components will be explained.

The drawing shows Align 23.6% = F CaSO447.0%
The basic component containing 19.5% of F-Ca is pulverized to 44μ or less (hereinafter referred to as α size), 44 to 8
8μ (hereinafter referred to as β size), 88 to 149μ (hereinafter referred to as γ size)
J l5R520 was created by sorting into four sizes, 149 to 250μ (hereinafter referred to as β size), and mixing 13% of each with cement by internal cutting.
This figure shows the measurement results of the free expansion coefficient of 1 mortar, and the following was found from the results.

In other words, α size (curve 1) is a finer powder than γ size (curve 3), but the onset of expansion is delayed, and β size (curve 2) and δ size (curve 4) both have a small absolute amount of expansion, or It is said that the characteristics of β size and δ size contribute most to the introduction of prestress even when the grout is restrained. Particles were first selected.

On the other hand, a similar experiment was carried out by changing the ratio of α size and γ size, and it was found that when α size is less than 20%, that is, γ size exceeds 80%, the initial expansion becomes a dog and the balance with the cement hardening period becomes unbalanced. In a state of collapse and restraint, the expansion force escapes due to creep, etc., making it impossible to introduce prestress.In addition, when the γ size is less than 20%, or the ′α size exceeds 80%, air dry curing is particularly important. In addition, although it is preferable not to have particles larger than 250 μ in size, there is no significant effect even if they are present in a range of 20% or less. 80%,
γ size 20-80%, 250μ or more and 20% or less,
If the total was not 100%, the particle size structure was supplemented with β-sized and/or δ-sized particles.

Next, to explain the chemicals, as organic glues, holivinyl alcohol, alkyl cellulose, carboxyl alkyl cellulose, etc. are used, and 0.0% of the basic ingredients are used.
A proportion of 1 to 2% is preferable, and the blowing agent is ACZn,
CaSi etc. are used and the basic components are 0.005 to 0.
．． The preferred cement dispersant is lignin sulfonic acid, naphthalene sulfonic acid formaldehyde condensate, sulfonated melamine, sulfonated polystyrene, etc., and the preferred ratio is 1 to 6% based on the basic components. Na2CO3゜N as a cement quick setting agent
a45io4. Na2804” 10 H2ONa
AA! 02 tNaHCO3, ZnCl2, klcl
a, CaCAl'2.

MgCl2. FeCl3. FeCl2. FeSO4゜F
e2(804) a 2M gB r2 y ZnI
2, cHcx3jCC14, triethanolamine, etc. are used, preferably in an amount of 0.5 to 10% based on the basic components, and these are as described in Japanese Patent No. 799240.

In addition, in order to further increase rapid hardening, 3Ca0 is made amorphous.
- A mixture of approximately equal weights of 3A1203/CaF2 and gypsum can be used in the range of 3 to 30%.

The present invention will be explained below with reference to Examples, and all percentages and parts described in the specification of the present invention are expressed on a weight basis.

Example 1 Align 23.6%, F-Ca S 0447.0%
and F-CaO], 9.5%, α size 40.
2%, β size 13.6%, γ size 28.7%, δ size 11.0% and 250-350μ6.5% basic component 86.1 parts, polyvinyl alcohol 0.9 part, aluminum Powder 0.009 parts, product name "
Mighty” Part 3, amorphous 3CaO, 3A120a
A cement admixture for grout prepared by mixing 10 parts of a mixture of equal weights of Ca F2 and anhydrite was mixed with ordinary Portland cement in an amount of 11% by internal grinding to produce a cement for grout.

Particle size of 5 to 0.15 mm is added to this cement hi o o part.
Table 1 shows the results of a physical test conducted on a mortar prepared by kneading 100 parts of acid and 37 parts of water as Experiment/161.

The prestress measurement was calculated from the strain of the reinforcing bars by injecting this mortar into a restrained formwork with a reinforcing bar ratio of 1.0%.For comparison, the particle size of the basic component was set to α size 93% and β size 7% ( Experiment A3 shows the results of a similar measurement using a known basic component of Blaine 9200ffl/,!7).

Next, in Experiment/161, the basic component particles were similarly measured for β size 50% and β size 50%, and the results were shown as Experiment/162.

[Brief explanation of drawings]

The drawing shows the free expansion coefficient as the particle size of the basic component changes, with curve 1 being 44μ or less and curve 2 being 44 to 88μ.
, curve 3 is 88-149μ, curve 4 is 149-250μ
This is the case when using a cement expanding material.

Claims (1)

[Claims] 1. In a composition comprising a calcium sulfoaluminate-based substance in which a small amount of an organic sizing agent, a foaming agent, a cement dispersant, and a cement quickening agent are present, the composition of the calcium sulfoaluminate-based substance is 3Ca0.3A1203.
．． 5 to 40% by weight of CaSO4, the balance being free gypsum or a mixture of this and free lime, the ratio of free gypsum to free lime being 1.5 times or more by weight, and calcium sulfoaluminate based. 44 to 88 particles of matter
μ and or 149-250μ, or 44μ
Below 20-80% by weight, 88-149μ 20-80% by weight, 250μ or more and 20% by weight or less, and the whole is 100%
If less than 44-88μ and or 149-250
A cement admixture for grout consisting of μ particles.