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15-08 <br /> <br />15-09 <br /> <br />Construction joints shall be clean and damp before continuing pipe <br />making operations. Cleaning construction joints shall consist of <br />removing all laitance, loose or defective concrete, coatings and any <br />other deleterious materials. If construction of the pipe stops short of <br />a manhole, the resulting joint must be reinforced with a concrete <br />collar. This collar shall extend at least one foot on either side of <br />the joint, shall have a thickness at least that of the pipe and shal! <br />completely encircle the pipe. <br /> <br />After the removal of forms the inside of the pipe will be inspected and <br />any required repairs shall be made. All porous and fractured concrete <br />shall be removed by chipping openings into the concrete pipe as directed <br />by the Engineer. The chipped openings and any holes cut in the pipe for <br />inspection or to facilitate removing the forms shall be repaired by <br />filling with concrete or dry patching mortar. <br /> <br />The flow line grade of the f~nished pipe shall not vary more than 0.10 <br />foot from the planned grade line. Variations in the internal diameter <br />shall not exceed one thirty-second inch (1/32") per inch of diameter. <br />Offsets at form laps sha]l not exceed the limits specified in the <br />following table: <br /> <br />Pipe Diameter <br /> <br />Maximum Offset <br /> <br />72" 7/8" <br /> <br />Form strut bearing plate indentations shall not exceed 1/8" and the <br />remaining interior surface of the pipe shall be equivalent to a steel <br />screeded finish. All extraneous concrete shall be removed from the <br />interior surface as soon as possible after placing. <br /> <br />Temperature: The temperature of concrete when it is being placed shall <br />not be more than 90° F, and not less than 40° F in moderate weather or <br />50° F in weather during which the mean daily temperature drops below 40° <br />F. Whenever the mean daily temperature in the vicinity of the work site <br />falls below 40° F for more than I day the concrete shall be maintained <br />at a temperature not lower than 50° F for-at least two days immediately <br />following the 48 hours allowed for removing forms and making repairs. <br />Where artificial heat is employed, special care shall be taken to <br />prevent the concrete from drying. The contractor shall employ effective <br />means, such as precooling of aggregates and mixing water or placing at <br />night, as necessary to maintain the placing temperature of the concrete, <br />below 90° F <br /> <br />Finishing: The interior surface of the pipe shall be equivalent to a <br />wood-float finish as specified in Section 51 of the Standard Specifica- <br />tions except for the form lap ridges. After the internal fixed forms <br />have been removed, the inside of the pipe shall be inspected. All rock <br />pockets, blisters, voids or similar defects shall be repaired <br />immediately in a manner approved by the Engineer. <br /> <br />CDS.1.14 <br /> <br />15-3 <br /> <br /> <br />