SOFTWARE DEVELOPMENT FOR DESIGN OPTIMIZATION OF PRESTRESSED CONCRETE BEAMS

Abstract

Under the scope of the present study, followings are the summary of present study: 1- MATPRE.01 Software can be used for design optimization of simply supported pretension Standard AASHTO PC-I beams, Standard AASHTO PC-Bulb Tee beams, NU I-Girders, Texas U-beams and California Bath Tub beams, simply supported pretension and posttension rectangular and tee beams, continuous two, three and four spans posttension Standard AASHTO PC-I beams, rectangular and tee beams. 2- MATPER.01 Software had been used in parametric study of simply supported pretension Standard AASHTO PC-I and PC-Bulb Tee sections, NU-I Girders, Texas U-Beams and California Bath Tub beams to develop equations for the relationship between the service moment and the minimum number of strands. 3- MATPER.01 Software had been used in parametric study of simply supported and continuous two spans posttension rectangular beams developing equations for the relationship between the beam span and the minimum depth. 6.3 Conclusions Under the scope of the present study, following conclusions can be made: 1- The influence of the concrete cylinder compressive strength, strand diameter, girder span and section geometry on the required number of strands and total cost for simply supported Standard AASHTO PC-I and PC-Bulb Tee sections, NU-I Girders, Texas U-Beams and California Bath Tub beams can be as follows: • Higher concrete cylinder compressive strength of 55 MPa comparing with concrete cylinder compressive strength of 40 MPa leads to reduction in required number of strands of (8 % to 10 %) increasing the cost by (4 % to 6 %). • Larger strand diameter of 15.2 mm about 20 % more than 12.7 mm strand leads to reduction in required number of strands of (25 % to 30 %). • The total cost increases with the increase of the pretension strands. • The total cost increases with the increase of the prestressed concrete beam depth. • The required number of pretension strands in simply supported Standard AASHTO PC-I, Standard AASHTO PC-Bulb Tee sections and NU-I Girders decreases by (10 % to 15 %) and (15 % to 20 %) for increases of (25 % to 30 %) and (35 % to 40 %) in the moment of inertia respectively. • The minimum depth and cost for girder span less than 45.0 m at girder spacing of 1820 mm can be achieved by considering Standard AASHTO PC-Bulb Tee sections.