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<br />Material passing
<br />No. 200 screen
<br />IDesignatian 161
<br />Lightweight material
<br />IDesignatian 181
<br />Clay lumps
<br />IDesignatian 13)
<br />Other deleterious.
<br />substances
<br />
<br />1/2'
<br />
<br />2
<br />
<br />1/2
<br />
<br />The sum of thj;! percentages of .all deleteriol:Js
<br />. substances in any size, as delivered to the mixer,
<br />',.shall not ex~ed 3 percent, by weight. Coarse
<br />. aggrega.te may. be rejected if it fails. to' meet the
<br />. following test requirements:
<br />
<br />II) . [;ps Angeles'ra.ttler test iDesignatian 2.1).-lf
<br />the ross. 'using Grading A, exceeds' 10 percent, by
<br />weight, at 100 revolutions or 40 percent, by
<br />vieigh.t, at 500 revolutions.
<br />
<br />(2) Sodium-sulfate test for s'oundness
<br />IDesignatian 191.-11 the weigh.ted average loss
<br />after 5 cycles, is more than 10 percent; by
<br />weight.
<br />
<br />(3) Specific gravity IDesignatian 10).-lf the
<br />specific' gravity (sat~rated surface-dry basis), is
<br />less than 2.60.
<br />
<br />The designations in- "parentheses refer to methods of
<br />test described in the Seventh ~l:Iltion of the" ~ureau
<br />of Reclamation Concrete Manuai.
<br />
<br />c. Separation.- The coarse aggregate shall be
<br />separated' into no~inal sizes and shall be graded, as
<br />. batched, as follows: .
<br />
<br />Designation
<br />of size
<br />
<br />Minimum percent
<br />retained on
<br />screens indicated
<br />
<br />Nominal
<br />size range
<br />
<br />3/4 inch
<br />
<br />3/16 to 3/4
<br />inch
<br />3/4 to 1 and
<br />1/2 inches
<br />1 and 1/2ta
<br />3 inches
<br />
<br />50 percent 0':1
<br />3/8 inch
<br />25 percent on 1
<br />and 1/4 inches
<br />25 per.ceot on 2
<br />and 1/2 inches
<br />
<br />1 and 1/2
<br />inches
<br />3 inches
<br />
<br />Coarse aggregate shall be finished screened on
<br />vibrating screens mounted over the batching prant,
<br />or at the option of the contractor, the screens may
<br />be mounted on the ground adjacent to the batching
<br />
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<br />. SPECIRCA,T10NS;NO, PC.6114'
<br />(SUPPLEMENTAL ,q6Tlc~ N.
<br />
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<br />plant.. the fjnisll "$~r1~eos,. if . installec;i ?~.~.
<br />'batching plarit,'.sliall be so mounted thlj
<br />vibration. of..the ~cr~ens wUI not be transmiH~
<br />or affect the. accuracy of the batching scares'
<br />sequence of coarse aggregate handling anQ~'
<br />management shall be such that, if final a'
<br />submerged cooling are used, excessive free. moi
<br />shall be removed and diverted outside of the
<br />by dewatering screens prior to finish screening
<br />that a uniform and stable moisture con(
<br />maintained in the plant storage and batchi,1]9.
<br />The method and rate of feed shall be such .t~
<br />screens will not be overloaded and' wil~ op ite
<br />properly in a manner that will result in a fi.~~ :C:i
<br />". .
<br />product which consistently meets 't~e.'. grl~
<br />requirements of these specilicatians....t*'..li..~ '~d
<br />produc.ts . shall pass direc.tly to tli~<i(1diV~. - 81
<br />batching bins. Material passing .the' 3lt8-i)'C~SJ' ";'''n
<br />that is removed from the coarse aggre:ga.te as a s"ult
<br />:.of the finish screening operation shalt"~.!!.~.~.ie ,~?~:.".
<br />. ..1.
<br />
<br />Separation of the coarse aggregate into the' sp~~~j~
<br />sizes, after finish screening, shall be such that~'I' ~n
<br />the aggregate, as batched, is tested by'.scre~dr ~~n
<br />the screens designated in the following tabUI t; ..g~,
<br />the material passing the undersize test~'~f~~n
<br />(significant undersize) shall not exceed 2 .J c1. t,
<br />by weight, and all material shall pass the ~.av.., ze
<br />test screen: . : ~.t ,~~
<br />
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<br />
<br />
<br />Size
<br />
<br />3/4-inch
<br />aggregate
<br />
<br />\[8 'i ~~h~;;.:
<br />ia ~d3~\-;.;~'
<br />:ihchesi."{'/~.
<br />4 inch~>t>
<br />. , ~ '
<br />
<br />No.5 mesh
<br />IU.S. Standard
<br />screeR) . ,'J.i
<br />5/8 inch ~.
<br />
<br />1 and 1/2.inch
<br />aggregate
<br />3-inch
<br />aggregate
<br />
<br />1 and 1/4
<br />~ nches
<br />
<br />"r.".
<br />Screens used in making the tests for undersf.z.le'~..O.d
<br />oversize will conform to ASTM Designation:. ~rl ~,
<br />with respect to permissible 'variations in 'a' ".g~
<br />Ij'"
<br />openings. .. ~:J"~:' ~
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<br />a. Source of aggregate.-Sand and coarse agg~~Qate
<br />
<br />for ~on~rete, ~nd sand for m?rtar and grout .~., . :\~e.
<br />
<br />obtamed by the contractor from any ap V~d
<br />
<br />source as hereinafter provided. ..:: ..~~:; .
<br />......1..
<br />~.t' .~:.
<br />Bureau of Reclamation tests performed on sa)1:1p)es
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<br />136. PRODUCTION OF SAND
<br />AND COARSE AGGREGATE
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