In　situations　when　external　chloride　penetration　is　the　cause　of　depassivation,　the　corrosion　process　may　start　from　the　outer　region　of　a　rebar,　which　might　expand　non-uniformly.　Therefore,　the　main　objective　of　the　present　work　is　to　explore　the　effect　of　non-uniform　corrosion　on　cracking　behavior　of　cover　concrete.　The　influences　of　concrete　heterogeneities　and　the　porous　layer　generated　at　the　rebar/concrete　interface　on　the　failure　patterns　and　the　corrosion　level　of　cover　concrete　are　considered.　The　random　aggregate　structures　of　concrete　are　built,　and　the　concrete　is　regarded　as　a　composite　composed　of　three　phases,　i.e.　the　aggregate,　mortar　matrix,　and　the　interfacial　transition　zones　(ITZs).　The　plasticity　damaged　model　is　employed　to　describe　the　mechanical　properties　of　the　mortar　matrix　and　the　ITZs,　and　it　is　assumed　that　the　aggregate　is　elastic.　Non-uniform　radial　displacement　with　a　half　ellipse　shape　is　adopted　to　describe　the　expansion　distribution　of　the　corrosion　products.　The　failure　pattern　and　the　corrosion　pressure　of　cover　concrete,　and　the　critical　corrosion　level　when　the　cover　concrete　cracks　due　to　non-uniform　corrosion　expansion　are　studied　based　on　the　meso-scale　numerical　method.　The　comparison　of　the　simulation　results　with　the　available　test　results　on　the　failure　pattern　of　cover　concrete　shows　fairly　good　agreement.　Moreover,　the　influence　of　meso-structural　heterogeneities　is　explored,　and　the　cracking　behavior　obtained　under　non-uniform　and　uniform　expansion　conditions　are　compared.　Finally,　the　influences　of　cover　thickness,　rebar　diameter　and　the　location　of　rebar　(namely　side-located　rebar　and　corner-located　rebar),　on　the　failure　pattern　and　the　corrosion　level　are　examined.　(C)　2014　Elsevier　Ltd.　All　rights　reserved.