ASTM C1660 is the ASTM standard specification for thin-bed mortar for autoclaved aerated concrete (AAC) masonry. It provides a technical reference for a mortar product intended for use with AAC units, helping define expectations for material suitability and consistent application. For manufacturers, specifiers, and purchasers, this standard matters because it supports clearer product evaluation, more consistent procurement decisions, and better alignment between mortar performance and AAC masonry requirements.

Purpose of ASTM C1660

The purpose of ASTM C1660 is to establish a recognized specification for thin-bed mortar used in AAC masonry construction. As a product standard, it helps frame the material requirements and performance expectations that are relevant when selecting or evaluating mortar for this specific masonry system. This makes it a useful technical document for quality control, specification writing, and compliance-focused purchasing. By defining a common basis for the material, the standard helps reduce ambiguity in product comparison and project acceptance.

Common use cases of ASTM C1660

This standard is commonly used when working with autoclaved aerated concrete masonry units that rely on thin-bed mortar joints rather than conventional thicker mortar applications. It may support product development, laboratory testing, submittal review, and specification of mortar intended for AAC wall systems. ASTM C1660 is also relevant for suppliers and contractors who need a shared reference when evaluating whether a mortar product is appropriate for AAC masonry installation and related project requirements.

Why ASTM C1660 matters

ASTM C1660 matters because it helps bring consistency to a specialized mortar product used in AAC masonry. A clear specification can support more reliable product evaluation, simplify procurement, and reduce the risk of using a mortar that is not suited to the system. For project teams, the standard can also improve communication between manufacturers, engineers, and installers by giving them a common technical baseline. In practice, that can help support compliance and better quality control.

• Thin-bed mortar for AAC masonry
• Material specification reference
• Product evaluation and compliance
• Quality control and procurement
• Technical basis for AAC systems