SOME EFFECTS OF FABRICATION PRACTICES ON STRENGTH CHARACTERISTICS OF REINFORCED CONCRETE CULVERT PIPE

Abstract

WITH THE RECENT INCREASE OF HIGHWAY CONSTRUCTION ACTIVITY, IT SOON BECAME APPARENT THAT THERE WAS A DEFINITE NEED FOR KNOWLEDGE CONCERNING THE MANUFACTURE, INSTALLATION, AND FIELD BEHAVIOR OF PIPE CULVERTS UNDER THE HIGHER FILLS THAT ARE USED. THE STUDY REPORTED IN THIS PAPER CONCERNS THE FABRICATION PRACTICES AND THEIR POSSIBLE RELATIONSHIP TO PIPE STRENGTH, FAILURE OF PIPE UNDER EMBANKMENT LOADS, AND THE FEASIBILITY OF REPAIRING OR RESTORING THE STRUCTURAL INTEGRITY OF IN-PLACE PIPE THAT HAVE BEEN DAMAGED. THIRTY-THREE SECTIONS OF 54-IN. DIAMETER, CLASS III PIPE WERE FABRICATED AND TESTED SO THAT THE FOLLOWING VARIABLES COULD BE STUDIED' /A/ TYPE OF LAP USED TO FABRICATE CAGES OF REINFORCING STEEL /LAPPED AND TIED OR LAPPED AND WELDED/, /B/ RELATIVE POSITION OF JOINTS OF INNER AND OUTER CAGES OF STEEL IN THE PIPE, /C/ POSITION OF JOINTS WITH RESPECT TO POINTS OF APPLICATION OF THE LOAD IN THE THREE-EDGE BEARING TEST, /D/ USE OF REINFORCED GUNITE LINER FOR REPAIR PURPOSES , AND /E/ EFFECT OF LATERAL RESTRAINT ON LOAD-CARRYING CAPACITY OF THE PIPE. RESULTS OF THE INVESTIGATION INDICATE THAT' /A/ THE 0.01- IN. CRACK STRENGTHS AND ULTIMATE STRENGTHS WERE SIGNIFICANTLY AFFECTED BY THE THREE METHODS USED TO PREPARE JOINTS IN REINFORCING CAGES; /B/ THERE APPEARS TO BE NO MEASURABLE DIFFERENCE IN PERFORMANCE OF PIPE IN WHICH JOINTS WERE SPACED 0 DEGREES APART, 90 DEGREES AND 180 DEGREES APART; /C/ LOAD-CARRYING CAPACITIES WERE NOT SIGNIFICANTLY AFFECTED BY ORIENTATION OF JOINTS IN THE THREE-EDGE BEARING TESTS; /D/ REPAIRS MADE ON STRUCTURALLY DAMAGED PIPE SUFFICED TO RESTORE ORIGINAL LOAD-CARRYING CAPACITY TO THE PIPE; AND /E/ RODS USED TO PROVIDE LATERAL RESTRAINT APPEARED TO INCREASE LOAD-CARRYING CAPACITY OF THE PIPE IN THE SAME PROPORTION AS INTERNAL STEEL.