A　numerical　computational　modelling　of　slump　tests　for　fresh　self-compacting　concrete　(SCC)　was　developed　in　this　investigation　based　discrete　element　method　(DEM).　The　coarse　aggregates　in　DEM　model　were　characterized　by　using　spherical　shapes　and　3D　irregular　geometries　obtained　by　scanning　real　aggregates,　respectively.　By　comparing　the　results　of　the　slump　simulation　tests　corresponding　to　the　two　geometric　models,　it　was　found　that　the　average　error　of　the　latter　was　smaller,　about　2.9%.　The　results　of　quantitative　analysis　of　the　rotational　kinetic　energy　for　both　found　that　the　motion　of　the　real　coarse　aggregate　model　was　more　consistent　with　the　actual　situation.　The　effect　of　coarse　aggregate　gradation　characteristics　on　the　flow　properties　of　fresh　SCC　was　investigated　based　on　the　real　coarse　aggregate　model.　The　results　indicated　that　the　increase　in　the　content　of　large-size　coarse　aggregate　or　its　replacement　of　small-size　coarse　aggregate　both　resulted　in　the　deterioration　of　the　flow　properties　of　fresh　SCC.　During　the　lifting　of　the　bucket　at　the　beginning　of　the　slump　test,　different　velocity　distribution　patterns　existed　before　and　after　the　complete　separation　of　the　bucket　from　the　concrete.　The　maximum　flow　velocity,　about　0.8　m/s,　occurred　when　the　bucket　was　not　completely　separated　from　the　SCC　and　was　distributed　in　the　top　part　of　the　inner　bucket.　©　2023　Elsevier　Ltd