JPS5849651A - Premixed cement mortar for joint - 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 a premixed cement mortar for joints, particularly a premixed cement mortar for joints with good adhesion and low shrinkage.

Traditionally, cement mortar has been widely used as a joint material in fields such as masonry work, plastering work, concrete secondary product work, civil engineering, and construction work, but cement mortar is inexpensive and relatively easy to use. Although it has the advantage of being thin, it has the fatal drawback of large drying shrinkage.

Due to this large shrinkage, there are major problems such as water leakage due to drying shrinkage cracks after construction and mortar peeling.

The present invention aims to solve these drawbacks, and it is intended to solve these drawbacks, and it is intended to solve these drawbacks. The present invention aims to provide a premixed cement mortar for joints that has good adhesion and low shrinkage by using a composition containing cement as a joint material.

In other words, the present invention i, tal Portland cement 1
00 parts (hereinafter the same), (t) 5 to 25 parts of l amorphous carunium luminate, (C) 15 to 35 parts of gypsum, 72725 to 400 parts of fdl boll, and (θ) fine bone. Material 'Y (al~+(11!) contains 10 to 500 parts per 100 parts in total of the ingredients.

The product of the present invention will be explained in detail below. The product of the present invention,
It is an instant mortar that consists of Portland cement containing four components, and can be used as a joint material by simply mixing it with water. Cement and sediment, normal, early strength, very early strength, medium heat and white Portland cement.

As the tbl component, amorphous calcium aluminate with a CaO content of 40 to 47 is preferable, and +(
! The l component may be any one of anhydrite, hemihydrate, and dihydrate, but anhydrite, particularly type 2 anhydrite, is preferred in terms of strength development.

The fineness of this item tb+ and component (C) is plain 3,
000cm2/fi or more, preferably i4,000-7
,000 2/i.

The ratio of the lbJ component and the fQ) component is 5 to 25 parts, preferably 10 to 2 parts of the bl component to 100 parts of the component [a].
part, tc+ component is 15 to 35 parts, preferably 20 to 30 parts. In this way, bl and (cl
This is one of the characteristics of the present invention, as it has not been considered in the past that a wide variety of ingredients are mixed.

When these tb+bl and +CI components are kneaded with water (a
It works together with the l component to impart rapid hardening properties, and also
Ca0-Az 203・30a80. -32H20
(etringite) forms and forms needle-shaped crystals with a dense internal structure, which is highly effective in reducing drying shrinkage eruptions. As a method for producing Y from Etrin, a calcyrano-sulfoaluminate-based expansive material may be used, but compared to the case where the amorphous calcium aluminate and gypsum according to the present invention are used for this fL. It is the same as having no effect at all, and the shrinkage reduction effect is
do not have.

Next, the reason for limiting the tb+ and (cll components as described above) is that if the component (b) is less than 5 parts or less than 15 parts (the C1 component is less than 15 parts, the drying shrinkage reducing effect is not significant, and fl)
This is because if one component exceeds 25 parts or the +c+ component exceeds 35 parts, it becomes difficult to control the setting time, resulting in poor workability and is not preferred. In addition, +1) J and fcI components? Commercially available additives such as Denka Q, TJ, etc. manufactured by Denki Kagaku Kogyo Co., Ltd. can be used in place of the BL and Cl components.

Next, it is a component necessary to further reduce shrinkage tv of the mortar during drying and improve adhesion, preferably 25 to 400 parts per 100 parts of the ta+ component. Add 50 to 80 parts of j.

If the proportion of Boran is less than 25 parts, the effect of reducing the amount of drying shrinkage is small, so that adhesion cannot be improved, and if it exceeds 400 parts, the strength development will be poor. Natural or artificial materials may be used as natural materials, such as basalts, weathered andesites, tuffs, volcanic ash, granite, Beppu rocks, etc. There are white clay, etc., and artificial bolans include clay slag, alum slag,
These include blast furnace slag and fly ash.

As described above, the compound containing gold (al~(dll) component (hereinafter referred to as cement composition) has rapid hardening properties, so it can be mixed relatively hard like joint mortar (Tallow 230). (mm or less), fine bone.

Type of material, particle size 1. Becomes more susceptible to the effects of impurities, etc.
The major drawback is that it is very difficult to control the setting time, resulting in poor workability. To eliminate this defect,
A fine aggregate with uniform grain size and few impurities is mixed in advance at a mixing ratio of 10 to 500 parts to 100 parts of the cement composition, which improves workability and strength. From the viewpoint of expression, the preferred range is 50 to 300.
Department. The fine aggregate used is commonly used fine aggregate such as river sand, sea sand, crushed sand, silica sand, or heavy wire aggregate.
Bye.

The product of the present invention obtained in this manner is highly versatile, having six properties: surprisingly low shrinkage, reduced occurrence of cracks, good adhesion, excellent workability, and rapid hardening. Telemix cement mortar for joints.

Next, the product of the present invention will be further explained with reference to Examples.

Example (+1 to 100 parts of Al component) 1 to (Cement with d-1 component mixed in the proportions shown in Table 1) Mortar was prepared using 100 parts of the composition, 100 parts of No. 5 silica sand, and 60 parts of water. Crosstalk UJ
From A. 6'202 restraint rod and measurement method? After curing at 20°C and 180% RH for 1 day after driving,
The restrained expansion yield of mortar cured at 0°C and 60% RH was measured. Note that the drying shrinkage reduction effect was judged by the shrinkage head from the large expansion of the trowel. Using the same cement mortar, we formed a mortar with a specimen size of 4 x 4 x 16 Crn, and measured the compaction strength of the mortar that was subjected to the same curing as the restrained expansion and contraction. The results are shown in Table 1.

2. (bl and (cl) components? A setting retardant consisting of 26 parts of citric acid, 70 parts of potassium carbonate, and 7 parts of sodium gluconate in the proportions of all to be mixed. % added.

Further, Denka CSAJ, a registered trademark of Denki Kagaku Kogyo Co., Ltd., shown as Experimental Flat 2, is a calcium sulfoaluminate-based expanding material different from +1)l and tc+ components.

What are the following ingredients listed in the first column? Using.

Ingredients material...
・Fu1 City Portland Cement (Denki Kagaku Kogyo Co., Ltd.) fbl...cao @Amorphous Calcium Aluminate (Blaine 4,300 27g) tel...Plain 5 ,100CTL2/ ,
! Next, the adhesion shear strength of the cement mortar of the comparison product of Experiment & 1 and the product of the present invention of Test 19 of the actual test was measured.

The results are shown in Figure 1. Curves 1 and 2
The adhesive shear strength was measured by the following method.

SS ring (inner diameter 15.6cx, outer diameter 16.5cffL
Fill a mortar with a flow of 17 Qmm into a 4cm diameter 160%RH room, and after drying it in a room at 20°C and 160%RH, mold the outer edge of the mortar into a circular plate (diameter 15cTL, height 4.5m).
)Use pressure from above to extrude the mortar. At that time, the load vP (in g), the inner surface area of the mortar filling ring yrA
(Yono 2), and the adhesion shear strength S is calculated using the following formula: 0
Figure 2 shows a plan view of the cracked test specimen. The bottom line is the mortar from Experiment 161? In the center of the test specimen used (
However, when the wood cracked and wrinkled at 7 days old, the dry yield was measured using the comparator method, and the result was -5.6X 107
It was 4. In addition, cracks appeared in the mortar test specimen of Experiment A2 after 3 months of age, and the dry yield a1ti 4-2
x 104 and Tko. ko wVr-nt,, experimental flat 19
No cracks were observed in the specimens using this mortar even after 6 months of age.

Table 2 shows the measurement results of dry degeneracy at each material age.

Table 2

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the material age and adhesive shear strength of the inventive product and the comparative product, with curves 1 and 2 showing the inventive product and the comparative product, respectively. FIG. 2 is a plan view of the cracked test specimen. Patent applicant Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] fal Portland cement 100 heavy dobe, +1)l
5 to 25 parts by weight of amorphous calcium aluminate, tc
+ Seikou 15-35 Heavy Enemies, ((11 Bobrun 25-4
A premixed cement mortar for joints containing 10 to 500 parts by weight of 00 heavy electric parts and (e) fine aggregate 'Y tal~(dl) for a total of 100 parts by weight of each fraction.