ABSTRACT
Althoughhighmodulusfibres,andtoalesserextentlowmodulusfibres, canincreasethestrengthofacementitiousmaterial,themaineffectof fibresistoincreasethetoughnessbybridgingcracksinthematrix. BeamsmanufacturedfromTypeIcompositeswhichformmultiplecracks canbeanalysedbystandardelasto-plasticmethods(Kalisky,1989)and arenotconsidered.TypeIIcementitiouscompositebeamsreinforcedwith longfibres,suchassteelwiresorpolypropylene,wherethepull-out lengthissolargethatthemaximumloadisattainedwithlittlelossin fibrebridgingstress,canbeanalysedapproximatelyusingtheengineers' theoryofbending(Nishiokaetal.,1975;BabutandBrandt,1978;Swift andSmith,1978;Limeta!.,1987a;Naamanetal.,1993a,b).However, formoreaccurateanalysisofallTypeIIcompositesfracturemechanicsis essential.TheanalysisofTypeIIcompositesusingtheengineers'theory ofbendingisconsideredfirst.
