The client has mentioned that third party testing of blocks cannot be done since the hardening process is already done.
The manufacturer can give a letter confirming the recycled content, as per the design. Kindly guide if this will be approved by GRIHA. If not, please mention the approved labs from where the third party testing can be done.
Please note that test reports cannot be substituted with declarations for compliance documents. 3rd party testing from any NABL accredited laboratory, IITs/ NITs or government departments is acceptable.