Lightweight composite materials produced from carbonatable calcium silicate and methods thereof

Patent metadata

Field	Value
Publication number	US-2016340261-A1
Application number	US-201514715497-A
Country	US
Kind code	A1
Filing date	May 18, 2015
Priority date	May 18, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

An aerated composite material produced from carbonatable calcium silicate compositions (carbonation cured AAC) that has a compressive strength equivalent to autoclaved aerated concrete (ordinary AAC) at substantially the same density and a process of production of the same are provided. The composite material of the present invention comprises: a plurality of bonding elements, each including a core comprising calcium silicate, a first layer which partially or fully surrounds the core and is rich in SiO 2 , and a second layer which partially or fully surrounds the first layer and is rich in CaCO 3 ; a plurality of filler particles having their particle sizes ranging from 0.1 μm to 1000 μm; and a plurality of voids; wherein the plurality of bonding elements and plurality of filler particles together form a bonding matrix and are substantially evenly dispersed in the matrix and bonded together, the plurality of voids are bubble-shaped and/or interconnected channels, a pore volume with a radius of 0.004 μm to 10.0 μm in the plurality of voids is 0.30 ml/composite material 1 g or less, and a estimated compressive strength expressed by the following formula (1): estimated compressive strength (absolute dry density=0.50)=compressive strength×(0.50÷absolute dry density) 2 is 2.0 N/mm 2 or greater.

First claim

1 . A composite material comprising:
a plurality of bonding elements, each including a core comprising calcium silicate, a first layer which partially or fully surrounds the core and is rich in SiO 2 , and a second layer which partially or fully surrounds the first layer and is rich in CaCO 3 ; a plurality of filler particles having sizes of particle sizes of 0.1 μm to 1000 μm; and a plurality of voids;
wherein
the plurality of bonding elements and plurality of filler particles together form a bonding matrix and are substantially evenly dispersed in the matrix and bonded together,
the plurality of voids are bubble-shaped and/or interconnected channels,
a pore volume with a radius of 0.004 μm to 10.0 μm in the plurality of voids is 0.30 ml/composite material 1 g or less, and
an estimated compressive strength expressed by the following formula (1):
Estimated compressive strength (absolute dry density=0.50)=compressive strength×(0.50÷absolute dry density) 2

is 2.0 N/mm 2 or more.

2 . The composite material according to claim 1 , wherein the pore volume with a radius of 0.004 μm to 10.0 μm in the composite material is 0.24 ml/composite material 1 g or less and the estimated compressive strength is 2.5 N/mm 2 or more.

3 . The composite material according to claim 2 , wherein the pore volume with a radius of 0.004 μm to 10.0 μm in the composite material is 0.19 ml/composite material 1 g or less and the estimated compressive strength is 3.7 N/mm 2 or more.

4 . The composite material according to claim 3 , wherein the pore volume with a radius of 0.004 μm to 10.0 μm in the composite material is 0.17 ml/composite material 1 g or less and the estimated compressive strength is 4.5 N/mm 2 or more.

5 . The composite material according to claim 4 , wherein the pore volume with a radius of 0.004 μm to 10.0 μm in the composite material is 0.15 ml/composite material 1 g or less and the estimated compressive strength is 5.0 N/mm 2 or more.

6 . The composite material according to claim 1 , wherein the plurality of bonding elements is chemically transformed from ground calcium silicate selected from natural or synthetic sources.

7 . The composite material according to claim 6 , wherein the ground calcium silicate comprises one or more of a group of calcium silicate phases selected from CS (wollastonite or pseudowollastonite), C3S2 (rankinite), C2S (belite, larnite, bredigite), an amorphous calcium silicate phase, each of which material optionally comprises one or more metal ions or oxides, or blends thereof.

8 . The composite material according to claim 7 , wherein the plurality of bonding elements are chemically transformed from ground calcium silicate by reacting the ground calcium silicate with CO 2 via a controlled hydrothermal liquid phase sintering (HLPS) process.

9 . The composite material according to claim 1 , wherein the filler particles are a CaO-rich material.

10 . The composite material according to claim 1 , wherein the filler particles are selected from the group consisting of lime and quartz.

11 . The composite material according to claim 1 , wherein the filler particles are selected from the group consisting of industrial waste, lime, slag, and silica fume.

12 . The composite material according to claim 1 , wherein the plurality of voids are formed by hydrogen gas, which is generated by reacting an aerating agent in an alkaline environment.

13 . The composite material according to claim 11 , wherein the aerating agent is a powder which includes at least one of aluminum, iron, calcium carbonate, and blends of the same.

14 . A process of production of a composite material, comprising the following steps:
forming a wet mixture, wherein the wet mixture comprises water, filler particles comprising CaO or Si having a size of a particle size of 0.1 μm to 1000 μm, ground calcium silicate particles, and an aerating agent has a water/solid ratio (W/S) of 0.45 or less; casting the wet mixture in a mold; allowing the aerating agent to generate hydrogen gas thereby causing volume expansion of the wet mixture; pre-curing the obtained expanded mixture to a hardness enabling it to be taken out from the mold and moved; cutting the obtained pre-cured expanded mixture into a desired product shape; and causing the cut expanded mixture to cure at ordinary pressure, 60° C. or more of temperature, a relative humidity of 65% or more, and an atmosphere of a CO 2 gas concentration of 95% for 6 hours to 60 hours.

15 . The process according to claim 14 , wherein the ground calcium silicate particles comprise one or more of a group of calcium silicate phases selected from CS (wollastonite or pseudowollastonite), C3S2 (rankinite), C2S (belite, larnite, bredigite), an amorphous calcium silicate phase, each of which material optionally comprises one or more metal ions or oxides, or blends thereof.

16 . The process according to claim 14 , wherein the temperature at the carbonation step is 80° C. or more.

17 . The process according to claim 14 , wherein the relative humidity at the carbonation step is 95% or more.

18 . The process according to claim 14 , wherein the time at the carbonation step is 40 hours or more.

Assignees

• Solidia Technologies Inc
• Asahi Kasei Construction Mat Corp

Inventors

• Atakan Vahit
• Sahu Sadananda
• Takase Hirotaka
• Kamata Takayuki
• Kanno Katsuhiko
• Fukasawa Yoshihito
• Deo Omkar
• Vuong David

Classifications

• Y02W30/91

  Use of waste materials as fillers for mortars or concrete · CPC title

• C04B38/0054 Primary

  the pores being microsized or nanosized · CPC title

• B28B1/50 Primary

  specially adapted for producing articles of expanded material, e.g. cellular concrete (chemical aspects {or making expanded aggregate} C04B) · CPC title

• C04B38/0058

  open porosity · CPC title

• C04B38/02

  by adding chemical blowing agents · CPC title