As　a　good　shielding　material,　heavyweight　concrete　is　largely　utilized　for　building　the　Concrete　Biological　Shielding　(CBS)　wall　of　the　commercial　nuclear　power　plant,　and　is　often　subjected　to　the　biaxial　loadings　with　a　strain　rate　possibly　varying　from　10−5s−1　to　10−2s−1.　This　paper　assesses　the　combined　effects　of　the　lateral　stress　and　the　strain　rate　on　the　compressive　strength　of　radiation-induced　heavyweight　concrete　on　the　example　of　serpentine　concrete.　For　this　goal,　a　3-dimensional　rectangular　numerical　concrete　specimen　containing　special　aggregates　and　ITZs　was　firstly　established.　Exposed　to　neutrons　of　different　fluences,　the　initial　damages　caused　by　the　fast　neutron　were　assessed　by　a　thermal-mechanical　approach.　Then,　a　series　of　static　and　dynamic　biaxial　compressive　tests　on　the　rectangular　specimens　having　initial　damages　of　different　degrees　were　carried　out　by　finite　element　analysis　via　ABAQUS.　The　failure　modes,　the　crack　patterns,　and　the　ultimate　compressive　strengths　of　the　pre-irradiated　serpentine　concrete　were　obtained　numerically.　Finally,　based　on　the　numerical　results　and　the　classical　＂Kupfer-Gerstle＂　(＂K-G＂)　criterion,　this　paper　derives　the　biaxial　strength　criterion　of　the　radiation-induced　heavyweight　concrete　undergoing　both　lateral　stress　and　strain　rate.　Through　the　formula,　it　was　found　that　the　fast　neutron　fluence　of　high　level　reduces　significantly　the　biaxial　compressive　strength　of　the　heavyweight　concrete.　Besides,　if　the　heavyweight　concrete　undergoes　additionally　lateral　stress　and　the　strain　rate,　the　biaxial　compressive　strength　could　be　enhanced.　The　enhancement　effect　was　maximized　at　the　lateral　stress　ratio　of　0.5　and　the　strain　rate　of　10−2s−1.　The　current　numerical　approach　was　developed　with　a　potential　application　to　the　lifetime　extension　of　the　heavyweight　concrete　infrastructures　used　in　commercial　nuclear　reactors.　©　2023　Elsevier　Ltd