Cement mixtures with alkali-intolerant matter and method
US5690729A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 27, 1995 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Jan 27, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2111/2023
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A method of reinforcing cement/concrete mixtures with alkali-intolerant reinforcements and/or aggregate, such as uncoated, common glass filament, plastic filament, fabric and roving made therefrom by reducing the pH of the mixture while in its plastic state, and/or after it has set and cured, to about 7. With a neutral pH, the alkali-intolerant reinforcements need not be coated to protect them from degradation. In the absence of alkalinity, the reinforcement and/or aggregate material bonds with the cement mixture to form a relatively stronger mixture, which can be shaped as desired, made part of permanently poured structures, cement boards and many other small and large products. By selecting appropriate and, if desired, different materials for the reinforcements and/or aggregate, the strength, flexibility, etc. characteristics of the product can be readily changed to adapt the product to the intended use. The pH is reduced by migrating such materials as CO.sub.2 and/or CO and O.sub.3 into the cement after it has cured and, if desirable, also during curing. The CO.sub.2 and/or CO and O.sub.3 for the chemical reactions to reduce the pH are most suitably obtained from flue gases of i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.