Accelerated Carbonation of Concrete Aggregate

Overview

This Gold Standard methodology covers technology-based carbon removal through accelerated carbonation of demolished concrete, known as concrete aggregate. Concrete aggregate is exposed to an increased carbon dioxide concentration so the gas reacts with calcium compounds in the cement phase and forms stable carbonate minerals, permanently storing the carbon dioxide. Eligible activities use either direct or indirect mineral carbonation at concrete recycling facilities before the aggregate enters downstream uses. Each credit represents one tonne of carbon dioxide permanently sequestered.

Sources: methodology document · Gold Standard

01 · Roles

The workflow as an explicit directed graph. In Graph each column is one role, so you can see who acts at each step; every node names the org.broadlistening.policy.block.* def it resolves to plus its input and output record. Data flow switches to a lineage view that makes explicit what data each node needs and makes, with dependency arcs tracing every record back to the node that produced it. Hover to trace, click to inspect; revise edges (dashed) send work back.

03 · Generated lexicon records

The records this methodology compiles to, ready to write to a PDS. The first tabs are the new policy engine records; the ★ claim.activity tab and those after it are reused ATProto Collective Funding Ecosystem records (org.hypercerts.*): the issued hypercert batch, its rights, an example verification attachment and a retirement receipt.

{
  "$type": "org.broadlistening.policy.methodology",
  "code": "GS-CSACA",
  "name": "Accelerated Carbonation of Concrete Aggregate",
  "registry": "Gold Standard (GS)",
  "sector": "Industry",
  "creditType": "removal",
  "status": "active",
  "version": "1.0",
  "scopes": [
    "Carbon removal"
  ],
  "roles": [
    {
      "id": "registry",
      "name": "Standard Registry",
      "permission": "Owns the policy, approves participants, anchors each issuance to its evidence."
    },
    {
      "id": "proponent",
      "name": "Project Proponent",
      "permission": "Registers the project and submits monitoring reports."
    },
    {
      "id": "vvb",
      "name": "Validation & Verification Body",
      "permission": "Independently validates the design and verifies monitored data."
    }
  ],
  "schemas": [
    "at://did:plc:bl0adl1sten1ngp0l1cyreg/org.broadlistening.policy.schema/gs-concrete-project-design",
    "at://did:plc:bl0adl1sten1ngp0l1cyreg/org.broadlistening.policy.schema/gs-concrete-monitoring-report"
  ],
  "graph": "at://did:plc:bl0adl1sten1ngp0l1cyreg/org.broadlistening.policy.graph/gs-concrete",
  "issuesAs": "org.hypercerts.claim.activity",
  "workScope": "at://did:plc:bl0adl1sten1ngp0l1cyreg/org.hypercerts.workscope.cel/gs-concrete-scope",
  "rights": "at://did:plc:bl0adl1sten1ngp0l1cyreg/org.hypercerts.claim.rights/gs-concrete-rights",
  "createdAt": "2025-01-01T00:00:00.000Z"
}

04 · Schemas

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