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IS 16758:2018 is the Indian Standard (BIS) for coarse recycled aggregate for use in concrete - specification. This standard specifies the requirements for coarse recycled aggregate (CRA) produced from construction and demolition waste for use in concrete. It covers classification, quality, physical properties, grading, and testing of CRA to ensure its suitability for various concrete applications.
Specifies requirements for coarse recycled aggregates derived from concrete, masonry, or mixed debris, intended for use in concrete.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! The higher water absorption of recycled aggregates compared to natural aggregates must be accounted for in the concrete mix design by adjusting the water content to maintain the target water-cement ratio.
! The source of recycled aggregate is critical; aggregate derived purely from crushed concrete waste generally has superior properties to that from mixed demolition debris.
! Careful monitoring of deleterious materials like gypsum, plastic, and soil is essential as they can negatively impact concrete strength and long-term durability.
JIS A 5021:2014JISC (Japanese Industrial Standards Committee), Japan
HighCurrent
Recycled aggregate for concrete-Class H, M and L
Directly specifies requirements for different classes of recycled aggregate for use in structural concrete.
GB/T 25177-2010SAC (Standardization Administration of China), China
HighCurrent
Recycled Coarse Aggregate for Concrete
Provides a detailed specification for recycled coarse aggregate, including classification, technical requirements, and testing.
BS 8500-2:2015+A2:2019BSI (British Standards Institution), United Kingdom
MediumCurrent
Concrete - Complementary British Standard to BS EN 206. Part 2: Specification for constituent materials and concrete
Defines requirements for using recycled aggregate in concrete by setting limits on its composition and properties within the UK.
EN 12620:2002+A1:2008CEN (European Committee for Standardization), Europe
MediumWithdrawn
Aggregates for concrete
A harmonized European standard for all concrete aggregates, which includes recycled aggregates as a defined type.
Key Differences
≠IS 16758 classifies Recycled Coarse Aggregate (RCA) based on the percentage of original concrete content (≥95% and 90-95%), whereas JIS A 5021 uses Classes H, M, and L based on performance characteristics like density and water absorption.
≠The maximum water absorption limit in IS 16758 is a single value of 5.0%. In contrast, JIS A 5021 provides tiered limits for its classes: ≤3.0% for high-grade (H), ≤5.0% for medium-grade (M), and ≤7.0% for low-grade (L).
≠IS 16758 sets a maximum Los Angeles Abrasion value of 40%. The Chinese standard GB/T 25177 is stricter for its highest grade (Class I), requiring a maximum value of 30%.
≠While IS 16758 specifies chloride content limits directly on the aggregate (e.g., ≤0.04% for RCC), European approaches like BS 8500-2 control the total chloride content in the final concrete mix, which is a more performance-based approach dependent on exposure class.
Key Similarities
≈All standards, including IS 16758, JIS A 5021, and GB/T 25177, mandate that the primary source of RCA must be processed concrete from construction and demolition waste, with strict controls on impurities.
≈There is a common requirement across standards that the particle size distribution (grading) of the RCA must comply with the established national standards for conventional coarse aggregates (e.g., IS 383 for India).
≈Testing for key mechanical properties to ensure durability and strength, such as aggregate crushing value, impact value, and abrasion resistance (Los Angeles test), is a standard requirement in IS 16758 and its international counterparts.
≈All referenced standards aim to ensure the produced RCA is free from harmful levels of contaminants like clay, wood, plastic, and other deleterious materials by specifying maximum allowable percentages.
Parameter Comparison
Parameter
IS Value
International
Source
Water Absorption (Max %)
≤ 5.0%
≤ 3.0% (for Class H)
JIS A 5021:2014
Los Angeles Abrasion Value (Max %)
≤ 40%
≤ 30% (for Class I)
GB/T 25177-2010
Aggregate Crushing Value (Max %)
≤ 30%
≤ 20% (for Class I)
GB/T 25177-2010
Chloride Content (for RCC, Max % by mass)
≤ 0.04%
≤ 0.02%
JIS A 5021:2014
Clay Lumps (Max % by mass)
≤ 0.25%
≤ 0.5% (as 'Soil Content' for Class I)
GB/T 25177-2010
Oven-dry Density (Min g/cm³)
Not Specified as a limit
≥ 2.50 g/cm³ (for Class H)
JIS A 5021:2014
Lightweight Materials (Max % by mass)
≤ 1.0%
≤ 0.5% (for 'Floating Matter' in RCAC)
BS 8500-2:2015+A2:2019
⚠ Verify details from original standards before use
Key Values6
Quick Reference Values
Maximum Water Absorption5.0 % by mass
Maximum Los Angeles Abrasion Value45 %
Maximum Combined Flakiness and Elongation Index40 %
Maximum Content of 'Other Materials' (Wood, Plastic, Metal)1.0 % by mass
Maximum Content of Asphalt1.0 % by mass
Minimum Dry-rodded Unit Weight1300 kg/m³ for 20mm nominal size
Tables & Referenced Sections
Key Tables
Table 1 - Physical Requirements for Coarse Recycled Aggregate
Table 2 - Grading Requirements for Coarse Recycled Aggregate
Table 3 - Guidance on the End Use of Concrete with Coarse Recycled Aggregate
What is the maximum permissible water absorption for coarse recycled aggregate?+
5.0% by mass, as per Table 1 of the standard.
What is the maximum allowed Los Angeles Abrasion value?+
The maximum permitted value is 45%, according to Table 1.
Can recycled aggregate concrete be used for structural purposes?+
Yes, Table 3 provides guidance on end-use, allowing it in M25 grade concrete and below for certain RCC elements, often with limitations on the replacement percentage.
What is the main difference between 'Recycled Aggregate' and 'Recycled Concrete Aggregate' in this code?+
'Recycled Aggregate' is derived from waste concrete, whereas 'Recycled Concrete Aggregate' can be derived from waste concrete mixed with other materials like bricks and mortar (Clause 4).