Can I use recycled fine aggregate in reinforced concrete (RCC)?

Yes, Annex A recommends up to 30% replacement of natural sand for RCC work (up to M25 grade), provided the FRA meets the quality requirements.

What is the maximum allowed water absorption for FRA?

The maximum water absorption is 5.0 percent by mass as per Table 1.

Is a special mix design needed for concrete with FRA?

Yes, the mix design must be adjusted for the higher water absorption of FRA to achieve the desired workability and strength. Refer to IS 10262 for guidance.

What is the maximum chloride content allowed in FRA for RCC?

The maximum chloride content is 0.04 percent by mass of aggregate, as specified in Table 2.

IS 16759

: 2018

Fine Recycled Aggregate for Use in Concrete - Specification

CurrentSpecializedSpecificationBIMMaterials Science · Aggregates and Sand

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This standard specifies the requirements for fine recycled aggregate (FRA) sourced from construction and demolition (C&D) waste for use in concrete. It covers material classification, physical and chemical properties, testing methods, and provides recommendations for replacing natural sand with FRA in various concrete applications.

Specifies requirements for fine recycled aggregates derived from concrete, masonry, or mixed debris, intended for use in concrete.

Quick Reference Values

Maximum Water Absorption5.0 % by mass

Maximum Chloride Content (for RCC)0.04 % by mass

Maximum Sulphate Content (as SO3)0.4 % by mass

Maximum Fines Content (<75 micron)5.0 % by mass

Maximum Allowable Replacement in RCC (up to M25)30 %

Practical Notes

FRA typically has higher water absorption than natural sand; this must be accounted for in mix design by adjusting water content to maintain the target effective water-cement ratio.

The source of the recycled aggregate is critical. Ensure it comes from a reliable processing plant with quality control to avoid contamination from gypsum, plastics, or other deleterious materials.

Start with lower replacement percentages (e.g., up to 30% as per Annex A for RCC) and conduct trial mixes to verify concrete performance before large-scale use.