ULTRA-LIGHT MINERAL FOAM AND METHOD FOR PRODUCING SAME
A method for producing a mineral foam includes: (i) independently preparing a cement slurry and an aqueous foam, the cement slurry being prepared by mixing water E and cement C, the cement C including a soluble equivalent quantity x of Na 2 O, x being expressed by weight for 100 parts cement, the slurry having a ratio x/(E/C) less than or equal to 1.75, E/C being expressed by weight, and the particles of cement C having a size distribution such that the particle size distribution ratio d max(h/2) /d min(h/2) is between 5 and 25; (ii) bringing the cement slurry into contact with the aqueous foam in order to obtain a foamed cement slurry; and (iii) shaping the foamed cement slurry obtained in step (ii) and allowing setting to take place.
1 . A Method for producing a mineral foam comprising the following steps:
(i) independently preparing a cement slurry and an aqueous foam, the cement slurry being prepared by mixing water W and cement C, the cement C comprising an amount x of soluble Na 2 O equivalent, x being expressed in weight per 100 parts of cement, said slurry having a ratio x/(W/C) less than or equal to 1.75, with W/C expressed by weight, and the particles of cement C have a particle size distribution such that the ratio d max(h/2) /d min(h/2) of the particle size distribution is between 5 and 25;
(ii) contacting the cement slurry with the aqueous foam to obtain a slurry of foamed cement; and
(iii) forming the slurry of foamed cement obtained at step (ii) and leaving to set.
2 . The method according to claim 1 , wherein the ratio x/(W/C) is less than or equal to 1.60.
3 . The method according to claim 1 , wherein the ratio d max(h/2) /d min(h/2) is from 6 to 14.
4 . The method according to claim 1 , wherein the cement is a cement of type CEM I, CEM II, CEM III, CEM IV or CEM V.
5 . The method according to claim 1 , wherein the cement has a Blaine specific surface area of 3 500 to 10 000 cm 2 /g.
6 . The method according to claim 1 , wherein the cement slurry comprises a water reducing agent of plasticizer or superplasticizer type.
7 . The method according to claim 1 , wherein the mineral foam comprises a mineral addition.
8 . The method according to claim 1 , wherein the mineral foam contains substantially no fine particles.
9 . The method according to claim 1 , wherein the W/C weight ratio of the cement slurry ranges from 0.23 to 2.0.
10 . The method according to claim 1 , wherein the aqueous foam comprises water and a foaming agent.
11 . A mineral foam obtainable using the method according to claim 1 .
12 . The foam according to claim 11 , having a dry density of 30 to 300 kg/m 3 .
13 . The foam according to claim 11 , having a thermal conductivity of 0.030 to 0.150 W/(m·K).
14 . A construction element comprising a mineral foam according to claim 11 .
15 . A method comprising utilizing the mineral foam according to claim 11 as insulating material.
16 . The method according to claim 2 , wherein the ratio x/(W/C) is less than or equal to 1.50.
17 . The method according to claim 15 , wherein the mineral foam is utilized as thermal or sound insulation.