A　laboratory　investigation　was　conducted　to　evaluate　the　structural　behavior　of　ferrocement　composite　panels　(FCPs)　incorporating　expanded　perlite　lightweight　aggregate　(LWA)　at　varying　volume　fractions　(55%,　35%,　and　15%).　Twelve　lightweight　FCPs　(60　×　60　×　4 cm)　were　fabricated　with　one,　two,　or　three　layers　of　expanded　rib　lath　and　tested　under　three-point　flexural　loading.　Structural　response　was　assessed　using　digital　image　correlation　(DIC)　and　theoretical　analysis　based　on　the　thin　plate　theory.　The　results　showed　that　increasing　the　number　of　rib　lath　layers　significantly　enhanced　the　first　crack　load　(Fcr)　and　ultimate　load　(Fu),　with　improvements　ranging　from　11　to　224%　in　Fcr　and　18　to　76%　in　Fu.　Deflection　at　first　crack　()　and　ultimate　load　()　increased　by　an　average　of　47%　and　229%,　respectively.　Additionally,　the　use　of　perlite　LWA　increased　and　by　29%　and　26%　compared　to　regular　FCPs,　highlighting　its　effectiveness　in　enhancing　flexibility.　DIC　analysis　identified　transverse　strain　(εxx)　as　the　most　sensitive　parameter　for　early　crack　detection.　Taguchi　optimization　further　revealed　that　the　number　of　rib　lath　layers　had　a　more　significant　impact　on　Fcr　and　Fu　than　perlite　content.　These　findings　suggest　that　a　three-layer　FCP　system　with　15%　perlite　replacement　optimizes　load-bearing　capacity,　making　it　well-suited　for　high-strength,　lightweight　applications　such　as　modular　buildings　and　prefabricated　structural　elements.　©　The　Author(s)　2025.