A SIMPLE METHOD IS DEVELOPED FOR CALUCLATION OF CRACK WIDTH AND CRACK SPACING IN REINFORCED CONCRETE MEMBERS. THE CRACK WIDTHS DETERMINED BY THIS METHOD WERE COMPARED WITH TEST DATA OBTAINED FROM FLEXURAL AND TENSILE MEMBERS REINFORCED WITH ONE BAR. THE SHAPE OF THE MAIN CRACKS WAS INVESTIGATED BY MEANS OF SHORT TENSION MEMBERS OF A LENGTH EQUAL TO THE SPACING OF THE MAIN TENSION CRACKS. THE INTERNAL CRACK FORMATION WAS DETERMINED DURING LOADING THROUGH INJECTION OF RESIN INTO A FEW TEST SPECIMENS. AFTER THE RESIN HAD HARDENED AND THE TEST MEMBERS WERE CUT OPEN, THE INTERNAL CRACK FORMATION WAS STUDIED. /RRL/A/