A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1986

This study deals with an analytical and experimental investigation of the crack spacing, crack width and composite behaviour before and after cracking of ferrocement in direct tensile loading. Effect of various parameters on crack spacing and crack width are studied. Applicability of the law of mixture for predicting the first crack strength is also included in the study . The theoretical derivation are based on the classical theory of cracking in reinforced concrete members based on the assumption that the tensile strength of the mortar surrounding the reinforcement are uniformely distributed over an effective cross-section and a certain bond stress exists along the reinforcement. The bond stress distribution was taken from bond-slip behaviour. To check the validity of the proposed theoretical model, an extensive experimental work was carried out by casting some tensile mortar prisms reinforced with small diameter wire in the longitudinal direction only. A computer program was developed for numerical calculation of crack spacing and crack width. For composite behaviour after cracking, numerical integration was included in the same programme. Experimental findings lead to the conclusion that i~ is possible to rationally predict design properties of ferrocement on the basis of composite material and reinforced concrete concepts. Results concerning onset of cracking and measurement of average crack spacing and width, developed under short term loading, are compared and good agreement was observed.