JPS59102849A - Super high strength cement hardened body - 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 ultra-high strength hardened cement body containing steel cut wool.

Conventionally, steel fibers were mixed in to increase the strength of hardened cement.
ing. Concrete mixed with steel fibers has a compressive strength of about 7001 KfJ/crn2 at most, with a water-cement ratio of about 40 to 60%.
- Due to the presence of fibers, the dimensions were adjusted to 2.5 to 2.5 mm to prevent the fibers from coming out of the concrete matrix.
It was necessary to use something of about 5α. Therefore, in order to further increase the strength of the hardened cement, if you try to mix such a size M into concrete with a low water-to-cement ratio, the concrete will become rough and it will be difficult to mix and shape the concrete. Ta. In other words, it was not possible to adopt a premix method in which fibers, mortar, concrete, etc. were kneaded together before forming the cured product.

As a result of various studies in order to eliminate such drawbacks, the present inventors have determined that steel cut wool with a fiber length of 0.05 to 1.5 cm is mixed with cement in an amount of at least 2% by weight, and the water-cement ratio is 65%. % or less, cement mortar/concrete can be reinforced with fibers using a premix method, and the present invention has been achieved by discovering that fiber reinforcement of cement mortar/concrete is possible and a remarkable strength enhancement effect can be obtained in ultra-high strength cement mortar/concrete.

The present invention will be explained in more detail below.

The steel cut wool used in the present invention is suitably pulverized steel wool that is commonly used9.
It is best to use fibers with a length of about 0.05 to 1.5 cm; fibers with a length of less than this are powder-like and will not have a fiber reinforcing effect, and if the fiber length is longer than this, the mortar and When mixing concrete, the load on the mixing mixer becomes too large, making mixing difficult. Especially 0.1 to 0.5
For those with α size, mortar Φ mixes well with concrete 0 Others, steel fiber k 0.0
It is also possible to use pieces cut into 5 to 1.5 sub-column sizes.
The thinner the fiber diameter, such as steel wool, the more preferable it is. The amount of steel cut wool mixed with the cement can be at least 2 parts by weight, preferably about 1 part by weight of 4ON, thereby significantly increasing the strength.

The cement paste, mortar, and concrete as the hydraulic cement compositions constituting the present invention must have a water-cement ratio of 65% or less, preferably 60% or less, and these hydraulic cement compositions In order to mix the ingredients uniformly, it is desirable to add a high-performance water reducing agent. As the high performance water reducing agent, common naphthalene sulfonic acid sodium formalin condensate 1. Sodium talamine sulfonate formalin condensate,
Examples include polymer sognine salts, cocondensates of these with alkyl groups, and the like. As the cement, general Portland cement type cement, alumina cement, rapid hardening cement, mixed cement, etc. can be used.

A hydraulic cement composition in which steel cut wool is mixed is mixed with an anhydrite-based strength-enhancing material (for example, Denka Kagaku Kogyo ■ product name [Denka Σ-100Dj)] and a cement expansion material (for example, Denka Kagaku Kogyo ■ product name [Denka Σ-100Dj]). Denka O8A”2DJ
According to the present invention, it is possible to produce a cement hardened body mixed with steel cut wool by a premix method, and ,
A cured product with extremely high strength can be obtained.

The following is a further explanation with examples. Using each of the materials shown below, mix cement paste or mortar at low speed using a mortar mixer specified in Revision 5R5201.
Table 1 shows the measurement results of mixability and compressive strength, which were formed into a frame with a vibrator and cured in 20°C water or 50°C hot water for a specified period after 1 day of age. Materials used〉 ・Early strength Portland cement: "Early strength Denka Cement"
Denki Kagaku Kogyo■ ・High performance water reducing agent: Methyl group-containing β-naphthalene sulfonic acid sodium formalin condensate/anhydrite-based strength enhancer: [Denka Σ-1000j Denki Kagaku Kogyo■ ・Activated silica fine powder: Ferro silicon manufacturing monument 1 product/
Sand; Paleozoic sandstone crushed sand 5 His Excellency (Okutamado), steel cut wool A: fiber fa length 0.05-1 mB: R fiber length 0
．． 1~0゜5m C: Fiber length 2.0tYn・Steel fiber D: Steel fiber with fiber length 2.5Crn/etc. - According to the trace shown in Table 1, experimenters 1 to 5 of the present invention example have a higher It was shown that the mixer had good kneading properties and had a high strength-enhancing effect.

Regarding the specimens of experiments A1, A4, and A8, 2
After curing in water at 0° C. for 28 days, the bending strength was measured and found to be 197 Kr/-1204 Kq/- and 151 Kq/cm2, respectively.

Patent applicant: Denki Kagaku Kogyo Co., Ltd.

Claims (1)

[Claims] An ultra-high-strength cement hardened material made by mixing at least 2% by weight of steel cut wool with a fiber length of 0.05 to 1.5 cm to cement, and making the water-cement ratio 65% or less.