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composed of one (1) ,part, Portland c:eraent anti tti^rd (2) parts sand.
<br />The in~;,redi::nts must be pro~uortioned by measurement and not b;r ~istimati on.
<br />They must be tlzor~ughly mixed dry in a suitable tight box, after vrh~;.ch t'r?.e pro-
<br />per qua.rrti.ty of clean v~rater shal]. be Gradually' added and then hot1d or ~rrorked
<br />until a uniform mixture is secured. Ido .G:r. eater quantity ~f mortar is i~o be
<br />prepared than is required for irunediate use, and any that has set shall not •be
<br />retompered ~r used s_n any tiray.
<br />Plo li?its or other admixtures of any descci>>tion shall be used unless so
<br />specified or pertni.tted by the .Engineer.
<br />16, cor~Ca=t~T~:
<br />(a) GEi~1E1~.~L: Concrete shall Co:,.Fii.st of a nt:i.xt.ure of Portland cement, aggregates
<br />and v.~ater, proportioned in accordaTice ~,Sr-.~th the req:}.irements of this s~?ec:Ll'ication.
<br />(b) PROPORTI011S: Trt ps'oportior~in.~•; concret? mate°rials, one (1.) bag (sack) of
<br />cement shall be considered as b^i.n~~ ono (1). cub'±c foot volume and ninety-four
<br />(9~.) pounds weight .
<br />Total maxiamuri ~^rater sYia.17.. be consider. ed as that incl~.ld:i:nG added grater and
<br />absorbed (surface) z-rat:=r i.ii tine ar;~;re•atos.
<br />Cetent shall be ttteasured by tireiC;ht and shall be vrei.~.;hed on a balance or
<br />scale separate from those used to ~veiGh tl?.e other i.n~•rr;d.ier.ts.
<br />A~;CreGates shall bo measured uy weight. Batch t^reil;hts sl.all_ be based on
<br />surface dried materi.aJ_s and shall be corrected to take into account the weir;ht
<br />of surface water conta:i.ned in t•he aggregates.
<br />ti~iater shall. be taeasu.rF;d by vol~une or 'c^reir;ht.
<br />Concrete shall be o.f' t:~o C1a.s~.es, Class "A" and Class "C", and shall be
<br />proportioned as folloti~rs
<br />C7.ass "?~" Class "C"
<br />i~iaximum water, l.allons per bag of cement 6-3/4 8
<br />I~I~inimLUn ceittent, bats per 1 cu. .ya. of concrete a-3/I~ ~.-1/2
<br />i~d.nimlun compressive stren~;tY., lb. per sq. in. at ?_8 daJs 3,000 2,000
<br />Pr'opor'tion by vol!une, cer~:;nt 'to total aC;greGate 1 tc ~-1/~ 1 to 7
<br />The proportions o.[' fine and coarse agC;:re~;ates shall be such as to produce
<br />the naxitnum density consistent ;•ril•h prober work:wbilit~.
<br />Class "A" concrete sha7.1 be used. for all .ret~~in~.z~~• ti°J~~:l.ls, culverts, special
<br />structures, manhole and catch basin b«se s7_ab,~, rznd ti~rh~~re othertivise specified or
<br />shown on the plans .
<br />Class "C" concrete; shall be us ea :f'or all sewer ~l~ipe bedcl.i~1£;: or cradles,
<br />concrete fillinb, and tivliere othez~vise sl?ecif.'Led o-r shoy~rrz on the plans.
<br />(c) I~~LCX:II`dC:: till concrote sl~.all L,o~ t1~:orouCh1~. ~nis;:ed i_n a batcl.~ ;uixor. of ap7:sroverl
<br />type for at least one and oz:a-L.ali m_i_nutes. I,~r l:•erni:iss-~ on o:i t1tE Lnr,a_neer, hated
<br />m1.Xlt1€; may be done in case Uf eli.E'.r°nCV Or '3dhE:T1 ,x,.::11 gllaIlt]._'t:l_P.S O:i COI1Crete ax'e
<br />required, and 1•rhere the use oy' a mixer is :un~:~racti.rab~_e.
<br />The use of "ready mixed" cortcr;:te ~~rill ~?e pertni~l:ted, pr. ovida_n~; it conforms
<br />tiv-i_th a1J_ the spec,:if'ic~:tions for coneret~. contai~iec lterei:t. Concrete so mixed
<br />m~_tst be nti~:ed, handl_ecl. anc.:~ t,r~.rsported so as to cause no sel;rel~.;`tlOTl of rstateri_als
<br />ti+r1~.Fn deposi~tecl, r;~nd :l~a.ll le ~nix"d :ot to c;:~ct:ed o~:,~: (1) lzotiz' before placi.nG,
<br />unless oth.c~rti~,r.i.,^,e pertn~.tteci l~,y the t~~nC;i.nec=r.
<br />Tree u.se of concrete, cemai~.t or rtorfi;ar ~^rlticlt hrz;~ keen ~artiall~r harcien~~d or
<br />Set 1^,111 YlO~t ~~ pF:Cli11'~,t~~C?.
<br />(cl) ?;Cr?i~iS. ?i'orr~zs of subst=.ntia;~ ..:a•~,e1•_ls.l sia1.1 be erec~:,ec :,~nd removed by the
<br />Cor_t~~'actor, ai1d. the cos-1, o:l.` s:~~ie :-;ha.il l:~e incl•?.c3.cc? :i.r; th•:: contract price per
<br />cu. j~•ci. of concre,~i;e.
<br />S - 1.1
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