Natural cement is valued as an authentic, historically accurate material for use in historic restoration. Accordingly, additions other than calcium sulfate and water are barred in the current standard. Nonetheless, functional additions used with other hydraulic cements, including set retarders and water reducers, can facilitate use of natural cement for certain restoration applications without compromising performance. Such additions are currently often being made as downstream modifications to natural cement grouts, mortars, concretes and plasters. The objective of this revision is to permit functional additions to natural cement and quick-setting natural cement that facilitate their use. Such additions would be required to comply with the ASTM C688 specification. In addition, all such additions would be required to be disclosed on the product labeling, providing purchasers, specifiers and users with the appropriate transparency needed to make conscious decisions regarding these additions to otherwise historically accurate materials.
hydraulic cement; natural cement; specification; Cement;
Citing ASTM Standards
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