Search

US-20260125325-A1 - Cement Board with Water-Resistant Additive

US20260125325A1US 20260125325 A1US20260125325 A1US 20260125325A1US-20260125325-A1

Abstract

In the present disclosure, a cement board is disclosed. The cement board comprises a core having a first surface and a second surface opposite the first surface and a binder including a pozzolan material and a water-resistant additive, wherein the water-resistant additive is present in an amount of less than 5 wt. % based on the weight of the pozzolan material.

Inventors

  • James Hickey

Assignees

  • PERMABASE BUILDING PRODUCTS, LLC

Dates

Publication Date
20260507
Application Date
20260105

Claims (20)

  1. 1 . A cement board, comprising: a core having a first surface and a second surface opposite the first surface and a binder including a cement, a water-resistant additive comprising a metal salt of a fatty acid including a backbone carbon chain having from 12 to 30 carbon atoms, wherein the water-resistant additive is present in an amount of less than 5 wt. % to greater than 0 wt. % based on the weight of the core, and a lightweight aggregate.
  2. 2 . The cement board of claim 1 , wherein the cement board exhibits a compressive strength of from 250 psi to 4,000 psi as determined in accordance with ASTM D2394.
  3. 3 . The cement board of claim 1 , wherein the cement board exhibits a compressive strength of from 700 psi to 2,000 psi as determined in accordance with ASTM D2394.
  4. 4 . The cement board of claim 1 , wherein the cement comprises Portland cement, magnesia cement, alumina cement, calcium sulphoaluminate cement, or a mixture thereof.
  5. 5 . The cement board of claim 1 , wherein the binder further comprises a pozzolan material.
  6. 6 . The cement board of claim 5 , wherein the pozzolan material comprises fly ash, blast furnace slag, metakaolin, silica fume, microsilica, or a mixture thereof.
  7. 7 . The cement board of claim 1 , wherein the core further comprises a normal weight aggregate.
  8. 8 . The cement board of claim 7 , wherein the normal weight aggregate comprises sand, limestone, stone, shale, clay, granite, or a mixture thereof.
  9. 9 . The cement board of claim 1 , wherein the lightweight aggregate comprises expanded shale, expanded clay, expanded vermiculite, expanded perlite, expanded pumice, expanded glass, expanded polystyrene, polyurethane, hollow spheres, or a mixture thereof.
  10. 10 . The cement board of claim 1 , wherein the lightweight aggregate comprises expanded polystyrene beads.
  11. 11 . The cement board of claim 10 , wherein the expanded polystyrene beads have a bimodal particle size distribution.
  12. 12 . The cement board of claim 1 , wherein the core further comprises a sulfonate, a cellulose polymer derivative, a polysaccharide, a galactomannan, or a mixture thereof.
  13. 13 . The cement board of claim 1 , wherein the water-resistant additive is present in an amount of from 0.3 wt. % or more to 2 wt. % or less based on the weight of the core.
  14. 14 . The cement board of claim 1 , wherein the fatty acid comprises from 12 to 24 carbon atoms.
  15. 15 . The cement board of claim 1 , wherein the fatty acid comprises stearic acid.
  16. 16 . The cement board of claim 1 , wherein the metal comprises an alkaline earth metal.
  17. 17 . The cement board of claim 1 , wherein the cement board exhibits a water penetration having an area of 0.2 in 2 or less as determined in accordance with ANSI A118.10 and ASTM D4068, Annex A2.
  18. 18 . The cement board of claim 1 , wherein the cement board exhibits a water absorption of 8 wt. % or less as determined in accordance with ASTM C473.
  19. 19 . The cement board of claim 1 , wherein the cement board exhibits a water vapor permeance of 10 Perms or more as determined in accordance with ASTM E 96/E96M-16, Procedure B.
  20. 20 . The cement board of claim 1 , wherein the cement board exhibits a fastener hold of from 50 lb f to 200 lb f as determined in accordance with ASTM C1396 and ASTM C473.

Description

RELATED APPLICATIONS This application is a continuation of U.S. patent application Ser. No. 18/356,328 having a filing date of Jul. 21, 2023, which is a continuation of U.S. patent application Ser. No. 17/155,238 having a filing date of Jan. 22, 2021, which claims filing benefit of U.S. Provisional Patent Application No. 62/965,347 having a filing date of Jan. 24, 2020, which are hereby incorporated by reference in their entirety. BACKGROUND Cement boards are typically utilized in the construction industry for various applications. Commonly used cement boards may have deficiencies regarding their waterproofing capabilities. For instance, water may pass through the board to the other building materials, which can create issues. For example, the penetration of water through a cement board may result in the growth of mold. Certain additives have been utilized. However, these additives may result in the board losing some of its original durability. As a result, there is a need to further improve the waterproof performance of cement boards while also maintaining its durability. SUMMARY OF THE INVENTION In accordance with one embodiment of the present invention, a cement board is disclosed. The cement board comprises a core having a first surface and a second surface opposite the first surface and a binder including a pozzolan material and a water-resistant additive, wherein the water-resistant additive is present in an amount of less than 5 wt. % based on the weight of the pozzolan material. DETAILED DESCRIPTION Reference now will be made in detail to embodiments, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the embodiments, not as a limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope or spirit of the present disclosure. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that aspects of the present disclosure cover such modifications and variations. Generally speaking, the present invention is directed to a cement board. For instance, the cement board includes a water-resistant additive that allows for an improvement with respect to the waterproof performance. In particular, utilizing a water-resistant additive in the amounts as disclosed herein provides advantages that can be beneficial for the construction industry. For instance, the present inventors have discovered that liquid water may not penetrate through the board in certain embodiments. Such test was conducted in accordance with ANSI A118.10 and ASTM D4068, Annex A2. For example, when studying the underside of the cement board, it did not appear that water penetrated the board. If water penetrates the board, a change in color can be observed. The change in color will be present within a certain defined area. In this regard, when conducting the test for the cement board as disclosed herein, such area indicative of any water penetration through the cement board may be 3.5 in2 or less, such as 3 in2 or less, such as 2 in2 or less, such as 1.5 in2 or less, such as 1 in2 or less, such as 0.8 in2 or less, such as 0.6 in2 or less, such as 0.4 in2 or less, such as 0.2 in2 or less, such as 0.1 in2 or less, such as 0.05 in2 or less. The aforementioned test is generally conducted for 48 hours. In this regard, such areas may be realized at 48 hours. However, the present inventors have discovered that water may not penetrate through the cement board even after having conducted the test for longer durations of time. For example, the aforementioned water penetration may be realized at 3 days, at 5 days, at 7 days, at 10 days, at 14 days, at 17 days, at 20 days, at 23 days, at 26 days, and/or at 30 days. Furthermore, the aforementioned test requires that all three specimens demonstrate no water penetration in order to pass the test. In some embodiments, all three specimens would exhibit no water penetration according to the conditions of the test. In other embodiments, two specimens may not exhibit water penetration. In a further embodiment, at least one specimen may not exhibit water penetration. In addition to water penetration, the cement board may absorb a minimal amount of water. Such water absorption may be determined in accordance with ASTM C473 (24-hour immersion) and may be less than 8 wt. %, such as 7 wt. % or less, such as 6 wt. % or less, such as 5 wt. % or less, such as 4 wt. % or less, such as 3 wt. % or less, such as 2 wt. % or less, such as 1 wt. % or less. Even with the reduction in the liquid water penetration and the water absorption, the water vapor permeance may not be negatively affected. In this regard, the water vapor permeance may be determined in accordance with ASTM E 96/E96M-16, Procedure B and may be 5 Perms or m