AASHTO M 259-20 pdf free download

AASHTO M 259-20 pdf free download.Precast Reinforced Concrete Box Sections for Culverts, StormI Drains, and Sewers.
1 0.2. Compression Testing of c’vlindeiv:
10.2.1. Cylinder Production—Cylinders shall be prepared in accordance with the Cylinder Strength Test Method of T 280.
10.2.2. Number of cylinders—Prepare not fewer than five test cylinders from a group (one day’s production of each concrete strength) of box sections.
1 0.2.3. Acceptability on the Basis of cylinder Test Results:
10.2.3.1. When the compressive strengths of all cylinders tested for a group are equal to or greater than the design concrete strength, the compressive strength in the group of box sections shall be accepted.
10.2.3.2. When the average compressive strength of all cylinders tested is equal to or greater than the design concrete strength, not more than 10 percent of the cylinders tested have a compressive strength less than the design concrete strength, and no cylinder tested has a compressive strength less than 80 percent of the design concrete strength, then the compressive strength of the concrete in the group of box sections shall be accepted.
10.2.3.3. When the compressive strength of the cylinders tested does not conform to the acceptance criteria stated in Section 10.2.3.1 or Section 10.2.3.2, the acceptability of the group shall be determined in accordance with the provisions of Section 10.3.
10.3. ‘ompress ion Testing of (‘ores:
10.3.1. Obtaining Cores—Cores shall be obtained and prepared in accordance with the Core Strength Test Method of T 280.
10.3.2. Number of (‘ores—One core shall be taken from a box section selected at random from each group of 15 box sections of a single size or fraction of such a group from each continuous production run.
10.4. Acceptability oil the Basis of Core Test Results:
10.4.1. When the compressive strengths of cores tested for a group of box sections is equal to or greater than the design concrete strength, the compressive strength of the concrete for the group is acceptable.
10.4.2. If the compressive strength of the core tested is less than the design concrete strength, the box section from which that core was taken may be re-cored. If the compressive strength of the re-core is equal to or greater than the design concrete compressive strength, the compressive strength of the concrete for the group is acceptable.
10.4.3. If the compressive strength of the re-core is less than the design concrete strength, the box section from which the core was taken shall be rejected. Two box sections from the remainder of the group shall be selected at random and one core shall be taken from each box section. If the compressive strength of both cores is equal to or greater than the design concrete compressive strength, the concrete compressive strength of the remainder of the group shall be acceptable. If the compressive strength of either of the two cores tested is less than the design concrete compressive strength, then the remainder of the group shall be either rejected or, at the option of the manufacturer, each box section of the remainder of the group shall be cored and accepted individually, and any of the box sections that have a core with less than the design concrete compressive strength shall be rejected.AASHTO M 259-20 pdf download.