# US 4,394,175 A · Self-levelling cementitious mixes

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,394,175 A
- Document ID: US4394175A
- Status: Granted
- Kind: A
- Application number: 06/261,325
- Filed: 1981-05-07
- Granted: 1983-07-19
- Earliest claimed: 1981-05-07
- Inventors: Leslie W. Cheriton; Philip J. Ansell
- Web page: https://patentgrep.com/patent/US4394175A

## CPC

- C04B 28/06: Aluminous cements (monolithic refractories or refractory mortars C04B35/66)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

A self-levelling cementitious mix, especially a screeding mix comprises high alumina cement and portland cement in non-critical proportions together with sufficient plasticizer and set retarder to make the mix workable in an acceptable setting period. Preferable proportions of the cement are 20-80:80-20 most advantageously 50:50.

## Claims

### Claim 1

A self-levelling screeding composition in the form of a free flowing paste, said composition comprising sand and other fillers, water, and hydraulic cement component comprising a portland cement and a high alumina cement characterized in that the cements are present in a weight ratio of 20-80:80-20 and in that the composition further includes a plasticiser component in a weight ratio of about 1% of the cement component to make the mix workable and sufficient of a set retarder component to delay the initial setting time about one hour.

### Claim 2 (depends on 1)

A composition according to claim 1, characterized in that the proportions of the cement are 30-70:70-30.

### Claim 3 (depends on 2)

A composition according to claim 2, characterized in that the cements are present in equal quantities.

### Claim 4 (depends on 1)

A composition according to claim 1, characterized in that the plasticiser is polymerised resin.

### Claim 5 (depends on 4)

A composition according to claim 4, characterized in that the chain length of the polymer may range from 6 to 70.

### Claim 6 (depends on 4)

A composition according to claim 4, characterized in that the plasticiser is melamine formaldehyde sulphonic acid condensate.

### Claim 7 (depends on 1)

A composition according to claim 1, characterized in that the concentration of the plasticiser is 1% by weight of the hydraulic cement component and about 1.4% by weight of the total powder composition.

### Claim 8 (depends on 1)

A composition according to claim 1, characterized in that the set retarder component is one or more of organic hydroxycarboxylic acids, organic acids or polyacids and salts or inorganic soluble salts of alkali metals.

### Claim 9 (depends on 8)

A composition according to claim 8, characterized in that the concentration of the retarder component is adjusted to make the mix have an initial set time of about one hour.

### Claim 10 (depends on 1)

A composition according to claim 1, characterized by the presence of a minor proportion of a powdered vinyl polymer.

### Claim 11 (depends on 1)

A composition according to claim 1, characterized by the presence of fine grade fillers.

### Claim 12 (depends on 1)

A composition according to claim 1, characterized by the presence of fillers which chemically react with the high alumina cement.

### Claim 13

A method of levelling the surface of a floor, comprising applying to the floor a paste of water and self levelling cementitious composition, the composition comprising:
sand and like fillers,
a hydraulic cement component comprising
a portland cement and a high alumina cement, the cements being present in a weight ratio of 20-80:80-20,
a plasticiser component in a weight ratio of about 1% of the cement,
a set retarder component in a proportion to make the initial set time of the composition be about one hour, the water being added in a proportion to form a free flowing paste, the paste being applied to a maximum thickness of about 3 mm and an average thickness of about 1.5 mm, and allowing the paste to set.

### Claim 14 (depends on 13)

A method according to claim 13, characterized in that the composition is allowed to set to an average thickness of 1.5 mm.