Infra-lightweight　concrete　(ILC)　is　a　type　of　lightweight　concrete　(LC)　with　a　dry　density　less　than　800　kg/m3.　ILC　has　extremely　low　self-weight,　excellent　heat　insulating　capacity　as　well　as　enough　structural　strength,　which　makes　it　suitable　for　a　wall　material　of　buildings.　However,　ILC　has　several　disadvantages,　such　as　easy　to　crack,　insufficient　durability　and　rough　surface.　Combining　ILC　(as　the　core　material)　and　fine　aggregate　concrete　(FAC,　as　the　surface　material)　to　form　a　sandwich　wall　can　make　best　use　of　the　advantages　and　bypass　the　disadvantages.　This　paper　presents　the　investigation　on　the　bond　behaviour　of　ILC　and　FAC　connected　by　fibre-reinforced　polymer　(FRP)　grids.　Finite　element　analysis　was　performed　and　experimental　verification　was　conducted.　The　results　show　that　the　simulation　analysis　agreed　well　with　the　verified　experiment,　both　the　tensile　and　shear　bond　strengths　were　positively　correlated　to　the　ILC　strength　grade,　and　the　FRP　grids　connection　could　significantly　increase　the　bond　strengths　between　ILC　and　FAC.　©　APFIS　2019.　All　right　reserved.