Non-Combustible Cement Board

1 - 36 . (canceled)

38 . A cement board, comprising:

a cement core having a first surface and a second surface opposite the first surface, the cement core comprising a binder comprising a cement, a lightweight aggregate, and a combustible additive, wherein the combustible additive is present in an amount of greater than 0 wt. % to less than 0.5 wt. % based on the weight of the cement core,

wherein the cement board passes CAN/ULC-S114:2018.

39 . The cement board of claim 38 , wherein the cement comprises Portland cement, magnesia cement, alumina cement, calcium sulphoaluminate cement, or a mixture thereof.

40 . The cement board of claim 38 , wherein the binder further comprises a pozzolan material.

41 . The cement board of claim 40 , wherein the pozzolan material comprises blast furnace slag, metakaolin, silica fume, microsilica, lime, or a mixture thereof.

42 . The cement board of claim 38 , wherein the cement board comprises 10 wt. % or less of fly ash.

43 . The cement board of claim 38 , wherein the cement board comprises 1 wt. % or less of fly ash.

44 . The cement board of claim 38 , wherein the combustible additive comprises expanded polystyrene.

45 . The cement board of claim 38 , wherein the combustible additive is present in an amount of 0.45 wt. % or less based on the weight of the cement core.

46 . The cement board of claim 38 , wherein the combustible additive is present in an amount of 0.4 wt. % or less based on the weight of the cement core.

47 . The cement board of claim 38 , wherein the lightweight aggregate is present in an amount of from 0.1 wt. % to 50 wt. % based on the weight of the cement core.

48 . The cement board of claim 38 , wherein the lightweight aggregate comprises expanded clay, expanded vermiculite, expanded pumice, expanded glass, hollow spheres, or a mixture thereof.

49 . The cement board of claim 38 , wherein the lightweight aggregate comprises expanded perlite.

50 . The cement board of claim 38 , wherein the lightweight aggregate comprises expanded shale.

51 . The cement board of claim 50 , wherein the expanded shale has a density of 75 pcf or less to 30 pcf or more.

52 . The cement board of claim 38 , wherein the cement core further comprises a normal weight aggregate.

53 . The cement board of claim 52 , wherein the normal weight aggregate comprises sand, limestone, stone, shale, clay, granite, or a mixture thereof.

54 . The cement board of claim 52 , wherein the normal weight aggregate is present in an amount of from 0.1 wt. % to 80 wt. % based on the weight of the cement core.

55 . The cement board of claim 38 , wherein the cement board has a density of from 40 lbs/ft3 to 80 lbs/ft3.

56 . The cement board of claim 38 , wherein the cement board exhibits a compressive strength of about 1,700 psi or less.

57 . The cement board of claim 38 , wherein the mean of the maximum temperature under CAN/ULC-S114:2018 is 35° C. or less, there is no flaming under CAN/ULC-S114:2018 during the last 14.6 minutes of the test, and/or the maximum loss of weight under CAN/ULC-S114:2018 is 19 wt. % or less.

58 . The cement board of claim 38 , wherein the cement board also passes ASTM E136-19a.

59 . The cement board of claim 38 , wherein the cement board exhibits an average weight loss of 50% or less when tested in accordance with ASTM E136-19a and/or the surface temperature of the cement board does not rise more than 30° C. when tested in accordance with ASTM E136-19a.

60 . A cement board, comprising:

a cement core having a first surface and a second surface opposite the first surface, the cement core comprising a binder, a lightweight aggregate, and a combustible additive, wherein the combustible additive is present in an amount of greater than 0 wt. % to less than 0.5 wt. % based on the weight of the cement core,

wherein the cement board passes ASTM E136-19a.