JPS5891047A - Cement additive - 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 The present invention relates to an additive for improving various properties of Portland cement-based cement (hereinafter referred to as cement) when hydrated.

Cement has excellent performance as a hydration hardening material, but its disadvantages include the tendency for floating water to come out during the initial hardening process (breathing phenomenon), low initial strength development, and volumetric shrinkage when drying. There are problems such as easy cracking. Recently, various improving agents (materials) such as strength accelerators, anti-breathing agents, and shrinkage reducing agents have been proposed in order to improve these problems during cement hydration hardening.

In order to meet this demand, the present applicant first used extinguishing bread stone as an additive in the hydration reaction of cement.
From a combination of Panyi 1 for baking, at least one of T water gypsum, hemihydrate gypsum, and anhydrous gypsum, and at least one of cow fj ash, 11 lime, and G ash. Developed a setting and hardening accelerator for cement.
423759). According to this invention, the composition of Idopanite, which is fired at 600 to 700°C, is
4), When it changes to K2SO4 and is suspended in water, △1'', 802. When water is added to Remen 1 and kneaded, these ions cause Ca2+OJ in the cement.
(FSO2- reacts rapidly, resulting in cement 1-11
The taste is strong, the production of L-living water is small, and L! Men 1 to 1 had the advantage of rapidly hardening, but the reaction occurred too rapidly, making it difficult to work on L men 11 when cross-connecting, and the compressive strength did not increase over a long period of time. the law of nature,
In addition, there was a drawback that cracks were likely to occur.

The name of the present invention is to eliminate this drawback.1 - After various investigations into the effect of unburnt alumite, which is added to cement as a hydration hardenability improver, we found that alumite powder was suspended in water. When the baking stones were suspended in water, the elution rate of Na+ was △1'', SO'a-J5 and +ma/, : was 1, and the rate of elution of Na+ was lower than when the baking stones were suspended in water. We investigated the method of using Akpan stone instead of Pan stone for kiln firing.

According to the results, the ions gradually eluted into water from Akpanite were 3CaO-810, J: and 2C,
a O・Si Ca (O11)2 eluted from O2
Because it reacts stoichiometrically effectively and slowly,
The hardening of cement l- is stable over a long period of time.
It has been found that it is no longer necessary to replenish sludge as in the invention of May 2003, and that a cured body of rethane 1 to 1 can be obtained with less generation of breathing water, high compressive strength, and no cracking.

Next, I will explain the experimental results.

The chemical compositions of ordinary Portland cement 1 and Akpanite used in the experiment are shown in Table 1.

Table 1 Aeroban Ei (50/7 sieve residue 2.1%, specific surface area 5800 cln2/CJ) was added and mixed to the concave portland cement ratio listed in Table 1, and the water/material ratio was 60%. 20°C. After curing at 90% humidity, as shown in Table 21
The compressive strength was measured over the following period and the results shown in Table 2 were obtained.

From the results in Table 2, we added Akpanishi Shinmi, which is not roasted, to Bortland cement and achieved hydration of 1! The reaction 14 caused by Akpanite occurs even when the mixture is reduced, and when 5 parts by weight of Akpanite is added to the amount of cement +OOa, the compressive strength increases compared to the case without addition of Akpanite. Is the compressive strength excellent even if more than 20 parts of Alarkite is added?/J It was recognized that the culm was rather reduced, and when Alarkite was added to 20 parts of Alarkite, the compressive strength was excellent. It was confirmed that when the following amounts were added, cracks did not occur in the cured product after the age of 28F1. In this case, slight cracks were observed at 91 days of age.

Next, the above-mentioned ordinary Bortland cement and Akpanite were mixed in a weight ratio not shown in Table 3, and 100 parts by weight of the mixture was mixed with Toyoura 11! Add and mix 200 parts of base sand, mix with 80 parts of water to make mortar, and conduct a breathing test at room temperature of 20°C (results obtained by measuring darkness of floating water). are shown in Table 3.

It is expressed as a volume percentage of water.

As shown in Table 3, it was found that the breathing rate was greatly reduced by adding Ampang to ordinary Portland cement.

Next, the above-mentioned ordinary polluland cement and alumite were mixed with 1111 parts of the ash shown in Table 4, and water/
The mixture was kneaded at a material ratio of 60%, molded in a mold with a diameter of 5 cm and a height of 10 cm, and the molded product was cured in humid air at 20°C and 90% humidity, and the compressive strength was measured for the period shown in Table 4. And the result in Table 4 is 1n.

From the results in Table 4, it was determined that the addition of Ura lime was 1 to 3 days old.
It was observed that the compressive strength increased by 15 to 30% over the age of 7 to 28 months, and cracks appeared in the cured product after 28 days. Make sure there are no cows.

Rani also has a particle size of 5. omm or more 1 coarse grain ratio 36 sand,
In advance, add 3 small skewers of J Ming bread (shown in Table 1) to the hanging part of 1001 sand, then add 20 and a half parts of water to 100 small skewers of this mixture, and use a mortar mixer. After kneading for 2 minutes, 20 parts by weight of Ordinary Pol] Heran 1 ~ Remen 1 ~
and kneaded for another 1 minute and 30 seconds, then 4X, l'
Mold in a 1x16c mold, wet at 20°C, wet at 90°C.
%rIDli! After IM air curing, immerse in water at 20℃,
11], 7 days and 28 days after molding, the bending J3 and F [cotton strength] of the rutar specimens were measured. For comparison purposes, the strength of mortar without Arkampite was also measured using the same method as above. Furthermore, the breathing rate at the 1st and 10th moldings was also measured. These results are not shown in Table 5, but from the results in Table 5), even when the amount of cement is mixed, the addition of Arkpanite significantly reduces the breathing rate and increases the strength of the effect. It is recognized that it is effective,
Moreover, it was confirmed that no cracks occurred in the cured product after 280%.

The present invention is based on these findings. h
It is a cement setting and hardening accelerator whose main ingredients are powder and slaked lime.

In the present invention, d-3 refers to cement l- to ordinary pol 1-land remen 1 and general portland [? Includes Men 1 ~ series Semen 1 ~.

Furthermore, in the present invention, Akpanite has a chemical formula of Na A
l, (SO2),, <0f-1)6 or KAI
, (804)2(011)6 as the principal component,
Cement 1-
It is preferable to add 1 to 50 parts by weight, preferably 1 to 30 parts by weight, and if slaked lime is added to promote initial strength development, it is preferable to add 1 to 50 parts by weight. Less than 50 parts per 100 parts, preferably number 1 (
) to 30 small parts are preferably added.

By adding and mixing the Akpanite of the present invention to cement, the breathing of rutar and concrete is prevented by J1.
However, it is not only possible to improve the initial strength and water permeability, but also the long-term strength due to the reaction between the components of slaked lime and Alpanite, which are released over a long period of time due to the hydration of the cement. drying shrinkage can be significantly reduced.

In order to increase the short-term strength of the cement, this can be achieved by pre-existing slaked lime before reacting the uncemented and light bread.

Claims (1)

[Claims] An additive for cement whose main ingredient is Akpanite.