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Architectural Specifications Addendum No. 2i WILSON - SHAVER Architects -Engineers Salina, Kansas ADDENDUM No. 2 14 April 1967 Job No. 1528 - 65-86 City, County, Board of Education Administrative Office Building Salina, Kansas To: All Prospective Bidders, Plan Rooms and Reporting Offices The contract documents for construction of the City, County, Board of Education Administrative Office Building, Salina, Kansas, dated March 1967, and amended by Addendum No. 1 dated 10 April 1967, are hereby further amended in the following particulars only all other terms and conditions remaining unchanged. I. Combined Proposal. Page CP -4 of combined proposal for construction of Salina Public Library and City, County, Board of Education Administrative Office Building is hereby superseded and replaced by revised page CP -4 dated 14 April 1967. II. Special Conditions. a. Mechanical Work - Storm Drains Pape SC -2 Subparagraph 2b., the following is hereby added at end of original subparagraph. "and storm drain lines included in Mechanical Work shall include those serving as collectors of roof drainage and terminating in an existing manhole on Ash Street." III. Technical Specifications. (1) In line 10 of subparagraph a. Fixed and Single Hung Windows the word "mill" is hereby deleted and the words "anodized 204 R1" sub- stituted therefor. (2) At end of second sentence of subparagraph b. Vertically Pivoted (Reversible) Windows the following is hereby added "with anodized 204 R1 finish". b. Storm Drains - Mechanical Work Page 21-1, Paragraph 1. Following sentence is hereby added at end of original paragraph. "Storm drain lines ticluded under this section are those serving as collectors of roof drainage and terminating in an existing manhole in Ash Street." Last two sentences of subparagraph are hereby deleted and the following substituted therefor. "Bidders shall base their proposals on furnishing and installing a Carrier Model 30HS unit, and may submit alternate proposals on Airtemp Model HRW, Trane Model CG, or other approved equal unit. Unit shall be complete with a factory fabricated and installed sound cabinet and re- mote condenser. Each compressor shall be connected with a separate refrigerant circuit to the chiller and condenser." Iof 2 C -2 - Addendum No, 2 JOB NO. 1528 - 65-86 14 April 1967 d. Blowers Page 22-7, Subparagraph lla. Following subparagraph is hereby added: "a. Vibration Supports. Each blower and motor shall be mounted on a spring mounted structural steel base with built-in motor slide rails, with 3" static deflection. Support shall be Korfund type "P", or equal." Eighth and ninth sentences of paragraph beginning in eleventh line are hereby revised to read as follows: "Liner shall be slipped into preformed round ducts with all joints coated with black mastic, Foster 31-95, and pushed firmly together. Elbows, tees, and fittings shall be lined with mitered sections of liner or elbows, tees, and fittings may be factory prefabricated double -walled internally insulated with perforated metal liner by United Sheet Metal Company, as specified in Paragraph 21, Ductwork." f. Storm Drains - General Construction, Page 26-1 Paragraph 1, Following is hereby added at end of original paragraph "Storm drain line included under this section is as defined under Part I - General Construction Work - Alternate G-8". IV. Drawings. a. Added Leter Sized Drawings Sheets 1 and 2 dated April 12, 1967, hereby supersede and replace in part original drawings for items as designated. b. Chiller Schedule Sheet M-7. E.W.T. shown as "55.0 degrees F" is hereby changed to "54.2 degree F." This Addendum is hereby a part of the contract documents to the same extent as though contained in the original documents and all itemized listings thereof. Each bidder shall acknowledge receipt of this Addendum in the space provided on the Proposal Form. WILSON -SHAVER, ARCHITECTS -/ENGINEERS Earl A. Graves EAG/djv Attachments: Revised Combined Proposal Blank -- Page CP -4 Added Drawings -- Addendum No. Two, 2 Sheets 2of2 Alternate No. G-8. For omission of construction of storm drain line and drainage structures, including drain inlet complete with frame and grates and storm drain manhole under service drive, to construction limits indicated, deduct from the Base Proposal the following sum: Written) Dollars ($ Alternate No. G-9. For construction of Terrazzo Flooring on entire first floor area east of elevator lobby (slab on fill) in. lieu of vinyl asbestos flooring as scheduled and including all necessary construction revisions required to effect this change, Add to Base Proposal the following sum: (Written) Dollars ($ PART I - ALTERNATE PROPOSALS SALINA PUBLIC LIBRARY Alternate No. G-1. For furnishing and installing granite from producers other than the Cold Spring Granite Company, add to or deduct from the Base Proposal the following sums: Granite Producer Names of Granite Add Deduct Alternate No. G-2. For furnishing and installing window walls and windows from manufacturers other than Alenco Aluminum Products, add to or deduct from the Base Proposal the following sums: Manufacturer Series No. Add Deduct Alternate No. G-3. For furnishing and installing vertical wood trim on column and wall corners, and random vertical wood strips on the west wall of Room 21 add to the Base Proposal the following sum: a. For walnut: Written Dollars ($ ) b. For birch: Written Dollars ($ ) CP -4 (Revised 14 April 67) I I A4 C4 Di OR 154 A:1 Cd OI 0.4 tut A4 04 CA Df. 54 DI C•3 AZ ! Ae2 64 X2 -- Q A4 5,1 CAI DI 'd2 A2 Al A2 A2 A�2 62 C$ vi , Q Q - _lT6M i. C":vl'.PANSLs AE5 010E IN TYPING KUDM. .a GHBDULED HSW1zCN TO WOIPK >�M \ rAFZfrIONS IN WOW N. ,ACOUSTICAL 41 PAk'TITIONS NOr N 05 Ph cV �GUS_ti' St�yN . 7 SAIJr rrAI AWAY PJY ADDENDUM NO. ONO WOfP1: RinoM \ W I LEON - 9NAVMR # I a28 CITY•COUNrr-worgL7ocA-naN A✓ 11Nr�7WATIVF- OFFI U,_a!NG �A I I OONINBOOQP TWACK ;;OW' F-WNWL MINIM lux 4:'Eh9Lrsc>, TO MICK, ? Vol MAX -, RACa t*M011c- WgFrTS --ISXF09AM-� Iro view �4 Q U Uo. U r. j1r WIN OOW 31LL-KGDM(a 2522,344sw374 IN WP CH I N C)Lk:;7 J N IT CALO CO NOr O=WD Nc). TWO OMIT MAC'2JLE �JfGY�L OR -L—, OF hM3 WHJrH L)o Nt7r,HAV.= IM1200TION UNIT OABPO AS, 9W7WN ON OHOE—, ii OF THE DqAWIN9B AND wNerrjeucr Aca NIL+7ON•9NAV6l� 1528 allOV4N AL20Va. CITY -COUNTY-F!pOoPEt'.:)UCAMON ICS VUILDINO - SALINA, K'AN9ACw Excavation shall be to elevations and dimensions indicated. Excavation 'for footings may be cut to accurate sizes and the side forms omitted, if concrete is poured without earth cave-ins. Excavation for foundation walls shall be of sufficient width to permit erection and removal of conventional double forms and shall be widened as required for installation of founda- tion drain lines where required. Excavation or fills for floor slabs shall be made or constructed to subgrade elevation (a minimum of 4 -inches below the bottom of floor slabs to accommodate base course). 6. Earth Fill and Backfill Within the Limits of New Construction shall be select, clean, moist earth, obtained from excavation for the building or from borrow, placed in uniform layers, properly moistened to approximate optimum moisture requirements and thoroughly compacted to 87 to 92 per cent of maximum density as determined by AASHO Test T 99-57. Fills and backfills to be hand tamped shall be placed in layers not to exceed four inches in depth. Fills and backfills to be rolled with power equipment shall be placed in uniform layers not to exceed six inches in depth. 7. Backfill Outside Building Limits. Backfill of excavations outside the limits of the building shall consist of suitable material, moistened and tamped or otherwise compacted to a density not less than that of adjacent undisturbed earth and such that no further settlement or shrinkage will occur. 8. Base Course under floor slabs shall be placed to minimum thickness as indicated on the drawings and shall consist of clean, washed sand or gravel having a minimum dry and rodded weight of 108 pounds per cubic foot and containing not more than eight per cent by weight of particles passing the No. 200 sieve or approved crushed stone material having a percentage of wear not to exceed 50 as determined by ASTM Standard C 131-64T. Material shall be compacted to maximum density by use of standard manufacture com- paction equipment consisting of a variable speed power unit attached to a vibratory plate. The vibrator may be of single or multiple type and shall provide sufficient unit pressure to obtain maximum compaction. The top surface of base course under floor slabs shall provide a smooth even surface. Prior to placing concrete over base course, the surface of the base course shall be covered with 1.5 -pound asphalt saturated felt or polyethylene sheeting of not less than 0.004 -inch thickness. 9. Drainage Fill for installation around foundation drain lines shall be clean gravel or crushed stone uniformly graded from 1 -1/2 -inch to 1/4 -inch size with a maximum of eight per cent passing the 1/4 -inch screen. Drainage !, shall be placed around foundation drain lines to full width and depth indicated. 10. Foundation Drain Lines. At the Contractor's option, foundation drain fl collection lines may be constructed of standard strength, plain end clay tile in 12 -inch lengths conforming to ASTM Standard C4-62, standard strength) perforated clay tile conforming to ASTM Standard C 211-61T or perforated asbestos -cement under drain pipe conforming to ASTM Standard C508 -64T for , 2-2 J • Type III. Fittings shall be of corresponding weight and quality. One- eighth bends shall be used for changes in direction and wye fittings shall be used at intersections. Lines shall be laid and firmly bedded to true grades and alinement with continuous fall in the direction of flow. Plain end tile shall be laid with 1/2 -inch open joints and top and sides of joint shall be covered with 15 pound asphalt saturated felt. Perforated drain pipe shall be laid with perforations at bottom. To insure drainage, before backfilling all lines shall be tested with water, any obstructions found removed, and the system again tested until satisfactory. Trenches containing collection lines shall be filled with graded crushed stone or gravel conforming to requirements for "Drainage Fill" specified herein- before. Top of foundation drain trenches to be covered with earth backfill shall be covered with one thickness of 15 pound asphalt saturated felt. 11. Grading. All ruts, holes and depressions caused by construction activities shall be filled and graded to match adjacent surfaces. During construction, the Contractor shall control grading in the vicinity of the building so the ground surface is properly pitched to prevent water from running into excavated areas. Water entering excavated areas shall be removed, excavation dried out and subgrade recompacted to its proper bearing capacity. A 25 -foot strip around the perimeter of the building shall be graded to provide positive drainage away from the building. 12. Subgrade Preparation for Drive and Walks. After excavating outside neat lines of concrete to allow for installation of forms, filling and rough grading have been completed, the subgrade shall be fine graded, moistened and compacted to a smooth uniform surface free from clods, lumps and loose, yielding material, and at proper elevation to provide full thickness of concrete. In cut sections, no special compaction will be required other than to prepare the surface. In fill sections and areas where necessary to remove obstructions and unstable or unsuitable subgrade material, the fill or backfill material placed in the subgrade shall be compacted to 87 to 92 per cent of maximum density as specified for back- fills within building limits. 2-3 SECTION 3 - CONCRETE WORK 1, General. Concrete shall consist of cement, coarse aggregate, fine aggregate, approved admixture when entrained air is required, and water; proportioned and mixed to produce a plastic workable mixture suitable to specific conditions of placement and in accordance with the following specifications. All reinforcement and embedded items shown and detailed, and embedded items furnished and located by other trades, shall be in- stalled and secured in place by ties, nails or supports prior to placing concrete. All requirements for prestressed concrete are contained in the paragraph entitled "Prestressed Concrete". 2. Strength of Concrete. Concrete shall have an average minimum compres- sive strength of 4,000 pounds per square inch at the end of 28 days. Strength of concrete shall be determined in accordance with ASTM Standard C 31-65 for preparation of test specimens, and C 39-64 for compressive strength. Operating mixes shall be adjusted if 7 -day strength falls below 2,800 psi for 4,000 psi concrete. Water -cement ratios and cement contents shall fall within specified ranges. Concrete made from high early cement shall have a 7 -day strength not less than specified minimum 28 -day strength for standard Portland cement concrete, 3. Sampling and Testing. All materials are subject to testing and in- spection prior to incorporation; all samples and test specimens shall be truly representative of material proposed to be furnished. The Contractor shall furnish and provide all samples and test specimens required and shall bear all expenses in connection with laboratory tests. a. Strength Tests. Contractor shall prepare test cylinders as re- quested as the work progresses, .Test cylinders shall be made and cured in accordance with ASTM C31 and shall be tested in accordance with ASTM C39 by an approved testing laboratory at the expense of the Contractor. A maximum of three test cylinders will be required for each pour of 5 to 50 yards and clearly identified as to location in structure where concrete represented by test cylinders was placed. One cylinder from each group shall be tested at.7 days and one at 28 days. Remaining cylinder shall be tested if results of 7 or 28 day test is below required strength. To be considered satisfactory, 7 day cylinder shall test 70 per cent of required • 28 -day strength. Testing laboratory shall furnish 5 copies of test results to Architect -Engineer without delay. If requested, test results shall be submitted on forms supplied by the Architect -Engineer and test result forms shall be fully filled out and complete when submitted. Tests for air con- tent in air entrained concrete shall be performed in accordance with ASTM C231 (pressure method). 4. Portland Cement shall be an approved brand of standard Portland cement, ASTM Standard C 150-65, Type I. or Type II, or when so authorized, high early strength portland cement, Type III. Use of special cements or those con- taining interground admixtures will not be permitted. All concrete exposed to view shall be made with cement of the same type and brand. Bulk cement shall be used direct from cars. Package cement shall be stored in a dry, ,I weathertight, properly ventilated building; each shipment identified and ;! arranged for easy access and inspection; turned and restacked to prevent it sack setting if not immediately used. 3-1 5. Aggregates. Coarse and fine aggregates shall be separately furnished and stored. Pit run or naturally mixed aggregates will not be approved; nor will mixing of aggregates from different sources or alternating batches of different aggregates in one stockpile be permitted. Sufficiently in advance of construction to permit standard gradations and proportions to be determined, the Contractor shall submit, to a testing laboratory, samples representative of each aggregate he proposes to use. Fineness modulus of aggregate furnished for construction shall not vary from such established standards by more than 0.2 plus or minus. Fineness modulus will be computed for each sieve analysis made, determined by adding respective cumulative percentages of material coarser than sieve in a U.S. standard series and dividing by 100. The series for fine aggregates shall consist of Nos. 4, • 8, 16, 30, 50 and 100; for coarse aggregates and total aggregates, 1 -1/2 - inch, 3/4 -inch and 3/8 -inch sieves shall be added to this series. a. Deleterious Substances in aggregates shall not exceed the following percentages by weight when tested under the designated ASTM Method. *Note: May be increased to 1.5 per cent if crusher dust. b. Coarse Aggregate shall be clean, hard, durable, uncoated fragments of crushed rock or gravel, reasonably free from thin or flat particles; having a loss ratio value of not less than 0.90 when tested for soundness by freezing and thawing in accordance with Section Y15 of the Standard Specifications for State Road and Bridge Construction of the State Highway Commission of Kansas, 1960 Edition; and having not more than 50 per cent wear under Los Angeles Abrasion Test, ASTM Standard C 131-64T. Aggregates known to damage concrete by expanding when exposed to moisture will not be approved. Coarse aggregate shall have a satisfactory record of use in concrete for a period of at least five years; material from new pits or outcrops shown to be extensions of acceptable deposits will be approved if the material passes all other requirements. (1) Gradation. Well graded, within the following limits when tested under ASTM Standard C 136-63. U.S. Standard Sieve Per Cent Retained 1 -inch Coarse Fine 0 - 5 Test Material Passing No. 200 Sieve (wash) 1.0* 2.0 C 117-62T Shale 0.5 1.0 C 123-64 Soft Friable Fragments 2.5 1.0 C 123-64 Sticks (wet weight) 0.1 Coal 0.5 1.0 C 123-64 Clay Lumps (on 3/8 -inch sieve) 0.3 0.5 C 142-64T Combined Shale, Coal, Clay Lumps and Soft Friable Fragments 3.0 3.0 *Note: May be increased to 1.5 per cent if crusher dust. b. Coarse Aggregate shall be clean, hard, durable, uncoated fragments of crushed rock or gravel, reasonably free from thin or flat particles; having a loss ratio value of not less than 0.90 when tested for soundness by freezing and thawing in accordance with Section Y15 of the Standard Specifications for State Road and Bridge Construction of the State Highway Commission of Kansas, 1960 Edition; and having not more than 50 per cent wear under Los Angeles Abrasion Test, ASTM Standard C 131-64T. Aggregates known to damage concrete by expanding when exposed to moisture will not be approved. Coarse aggregate shall have a satisfactory record of use in concrete for a period of at least five years; material from new pits or outcrops shown to be extensions of acceptable deposits will be approved if the material passes all other requirements. (1) Gradation. Well graded, within the following limits when tested under ASTM Standard C 136-63. U.S. Standard Sieve Per Cent Retained 1 -inch 0 3/4 -inch 0 - 5 3/8 -inch 40 - 60 No. 8 95 - 100 3-2 c. Fine Aggregate shall be clean, durable siliceous or calcareous particles, free from adherent coatings, and having a mortar strength not less than 100 per cent of standard Ottawa sand, ASTM Standard C 87-63T. (1) Organic Impurities. Aggregates subjected to colorimetric test for organic impurities, AASHO Test T 21-60, and producing color darker than standard, will be rejected unless passing the mortar strength test. (2) Gradation. Well graded, within the following limits when tested under ASTM Standard C 136-63. Blending will be permitted if necessary to meet the following gradation limits. • U.S. Standard Sieve Per Cent Retained 3/8 -inch 0 No. 4 0 - 5 No, 16 20 - 40 No. 50 80 - 90 No. 100 95 - 100 d. Storage. Build free drainage stockpiles in horizontal layers to avoid segregation. Protect from freezing or the inclusion of frost. Avoid inclusion of foreign materials. If absorption of coarse aggregates (AASHO Test T 85-60) be two per cent or more, maintain uniformly moist conditions throughout stockpile by daily sprinkling. 6. Water shall be clean, clear, odorless and fit to drink. Test under AASHO Test T 26-51, if of questionable quality. 7. Admixture. All concrete which will be exposed to the weather in the finished work shall contain an air entraining agent; all other concrete may contain an air entraining agent at the option of the Contractor. Admixture shall be added at the mixer in strict accordance with the manufacturer's recommendations. No reduction in the specified cement content will be permitted due to claims of added strength resulting from addition of any admixture. Air -entrained concrete shall have an air content of 4.5 per cent, plus or minus 1.5 per cent, when tested in accordance with ASTM • Standard C 231-62. Air entraining agent shall be Vinsol Resin, Darex AEA, Protex AEA or approved equal agent conforming to the requirements of ASTM Standard C 260-65T. 8. Proportioning. Concrete shall be proportioned within the following limits; all materials being measured by weight, considering one sack of cement as 94 pounds and one gallon of water as 8.33 pounds. Minimum Maximum Cement content, sacks per cubic yard concrete 5.5 6.25 Total water, gallons per sack cement 5.0 6.5 Coarse aggregate, per cent total aggregate 30 60 Fineness modulus, total aggregate 4.2 5.5 Entrained air per cent total batch weight 3 6 Slump, inches 1.5* 5 *Minimum slump is maximum for mass concrete and slabs. 3-3 9. Preliminary Mixes. The Contractor shall design preliminary mixes for trial batches and shall mix trial batches and prepare test cylinders for determination of 7 -day and 28 -day compressive strengths from such trial batches as have other acceptable characteristics. Operating mixes shall be based on information obtained from preliminary mixes. 10. Operating Mixes. a. General. Batching and weighing devices shall provide positive means of regulation and control and shall be accurate within 0.5 per cent for aggregates and bulk cement; all such devices and methods of operation shall be subject to inspection and approval. When packaged cement is used, • batch weights shall be proportioned to use whole sacks of cement. When batch trucks are used, each batch compartment shall be charged with all dry ingredients for one batch. b. Variations for Basic Mix. Exact proportions of basic mix may be varied within specified range limits as required to obtain concrete of specified strength and having other desired characteristics. (1) Proportions of Aggregates. Batch weights of coarse and fine aggregates shall be adjusted to use least amount of fine aggregate which will produce workable concrete having proper slump. If impossible to produce concrete of proper consistency, gradation of aggregates shall be corrected or total batch weight of aggregate reduced. No additional payment will be made for improvement of aggregate gradation, correction of proportions, or additional cement required by reason of such adjustment. (2) Corrections for Aggregate Moisture. Amount of water added at mixer shall be adjusted for moisture contained on the surface of aggre- gates and for absorptive qualities of the aggregates. Absorption of aggregates shall be determined by AASHO Tests T 84-60 and T 85-60. Batch weights of coarse and fine aggregates shall be adjusted to compensate for moisture contained at time of use. (3) Correction for Entrained Air. Air entraining agents shall • be added only at the mixer and in such quantity that amount of air entrained will be within specified limits. Should entrained air result in bulking of concrete, proportion of aggregate coarser than No. 50 sieve shall be in- creased by an amount equal to percentage of entrained air, fineness modulus of total aggregate remaining within specified gradation percentages of other sieve sizes to remain unchanged. (4) Yield Test. Cement content of concrete shall be determined by yield tests conducted under ASTM Standard C 138-63. If cement content falls outside specified limits, batch weights shall be adjusted until con- crete conforms to requirements. 11. Forms. Construct approved mortartight forms of suitable materials to provide surfaces free from surface irregularities; true to lines, grades and dimensions shown; rigid and properly braced to prevent movement or 3-4 distortion; internal ties so arranged that metal will not show or discolor concrete surface. Provide camber at mid -spans to offset anticipated de- flection in forms due to weight of fresh concrete. Provide a formed chamfer at all corners exposed to view using approved tapered rubber or plastic chamfer strips. Forms for rustications in concrete shall be accurately constructed to produce uniform and evenly spaced rustications. Design forms to permit proper installation of reinforcement; easy placement and manipulation of concrete; and removal of forms without damaging concrete. Apply an approved nonstaining form oil or sealer to plywood forms or form lining for concrete exposed to view in the finished work; apply water or nonstaining mineral oil to interior surfaces of forms for other concrete; • obtain approval of forms prior to placing concrete. Where practicable, concrete may be placed directly against undisturbed excavated surfaces without use of outside forms if concrete as placed provides a minimum of three inches outside cover over reinforcement. Before placing concrete, forms shall be cleaned with water jets or compressed air and all trash and debris shall be removed through access openings provided in forms. Form ties for exposed work shall be an approved type that shall leave no metal closer than 1 -1/2 -inches from the finished surface and no hole or depression larger than 7/8 -inch in diameter. Form ties for walls below grade and in locations not exposed in the finished work may be snap -type ties with not less than 1 -inch breakback. a. Ribbed Slab Forms. Ribbed slabs shall be constructed with removable metal pans or approved fiberglass, waterproof fiberboard or waterproof card- board pan forms. Pan units shall be closely and neatly fitted together and shall be sufficiently tight to prevent loss of grout during pouring. Pan units shall form a true, clean, smooth surface, free of honeycomb and rough exposed aggregate area when forms are stripped. Ceilings to be left exposed in the completed structure, shall be formed with well -fitting undamaged pans and shall have projecting ridges dressed off flush; pitting and other sur- face defects shall be pointed flush and rubbed with burlap. 12. Form Lining. Wood or metal forms used for exterior and interior con- crete surfaces to be exposed to view in the finished work, including painted and unpainted surfaces, shall be lined with smooth faced material furnished • in standard length sheets not less than 48 inches wide where practicable. a. Fiberboard Insulation Material. Not less than 3/16 -inch thick. Not to be used on steel forms, nor reused on wood forms. b. Plywood. Not less than 1/4 -inch thick. Not to be used on steel forms. If in good condition, may be reused on wood forms. c. Installation. Forms for areas four feet or less in width shall be lined with a single width of material. Each sheet shall be matched to fit abutting edges, with square corners and straight edges; joints shall fit snugly without forcing. Fiberboard and plywood shall be secured to backing with three -penny shingle nails, or similar nails having flat thin heads, spaced along edges at not more than eight inches on center and on 12 -inch staggered centers over balance of sheet. All joints in lining shall be sealed smooth with cold water putty, patching plaster, or similar nonstaining material. 3-5 d. Plywood Form Sheathing. At the Contractor's option, forms for exposed concrete may be constructed of 3/4 -inch plywood in lieu of metal or wood backing and form lining as specified above. If plywood form sheathing is used, studs shall be spaced not more than 16 -inch centers. Installation shall be equal to that specified for form lining. Such sheathing shall be maintained in good condition, oiled before initial using, and sandpapered and oiled before each reusing. 13. Reinforcing Steel. Install all reinforcement shown, including rods, fabric or structural shapes. Furnish shop drawings, lists and bending diagrams. Remove rust, scale, grease or any coating which might impair bond with concrete. Support reinforcing steel to obtain coverage and • minimum spacing and provide splice lengths as required by American Concrete Institute Manual of Standard Practice. Supports shall be galvanized or shall have plastic feet where located in soffits or faces exposed to the weather or in slabs to receive plaster. Reinforcing steel shall conform to the following ASTM Standards. Welded Wire Fabric A 185-64 Deformed Rods A 61-65 or A 432-65 (A 15-65, A 16-65 or A 160-65 may be used for column ties or beam stirrups) Deformation of Rods A 305-65 14. Embedded Items. Before placing concrete, remove coatings of oil, rust, scale or other foreign matter. Kerf and thoroughly soak wood strips used to form rustications, grooves, key joints and bevels. Slots for masonry anchors shall be dovetail type, formed of not lighter than 24 gage galvanized sheet steel, and shall be furnished with felt or fiber fillers. Slots shall be installed, vertically, in all concrete walls and columns faced with masonry (spaced 16 inches on center horizontally); in concrete walls and columns where masonry walls abut the concrete surfaces; and else- where as indicated. Slots shall not be installed in concrete beams. Strips for rustication shall be fastened to forms in such manner that forms can be removed without disturbing rustication strips and strips shall be left in concrete until thoroughly dry (at least 14 days). 15. Mixing and Placing, • a. Equipment. Provide one or more approved batch type mixing plants with rated individual capacity of at least one sack cement; equipped with adequate facilities for accurate measurement and control of all materials and for readily changing the proportions of the mix; and designed to permit all operations to be easily inspected at all times. b. Ready -Mixed Concrete. At the Contractor's option, ready -mixed concrete may be used provided all other requirements are complied with and the Architect -Engineer is permitted free access to the mixing plant. 3-6 L. Mixing. Operate mixer at speed and volume capacity recommended by manufacturer. Allow mixer to revolve at uniform speed for at least 12 revolutions after charging and for the following minimum time interval: 1/2 cubic yard or smaller, one minute; more than 1/2 cubic yard, 1-1/2 minutes. Avoid overmixing to point where additional water is required. d. Conveying. Using methods which prevent segregation or loss of ingredients, convey concrete from mixer to final position as rapidly as practicable. Use chutes only when necessary, and only when the slope is such that the concrete slides but does not flow. Use tremies or elephant trunks where concrete is to be placed under water or where vertical drops greater than eight feet are necessary. • e. Placement. Place concrete as soon as possible after mixing and in any case before initial set occurs. In General, place concrete on clean, damp surfaces, the temperature of which shall be 40 degrees F or above. Earth subgrade shall be approved undisturbed earth or properly consolidated material, free from running water and soft mud. Sand sub - grade or crushed stone base course shall be completely confined, thoroughly dry; under floor slabs, they shall be covered with waterproof sheathing paper or polyethylene sheeting installed with all joints lapped and sealed. Concrete shall be deposited in final position without re- handling or flowing; worked into all corners and angles of forms and around reinforcement and embedded items; and spaded and vibrated to maxi- mum subsidence without segregating, applying vibration directly to concrete, not to forms or reinforcement. Maximum depth of horizontal, layers when placing concrete shall not be more than that which prevents segregation or formation of visible seams. Pour supporting walls and columns to the underside of concrete beams and slabs at least eight hours prior to placing the superimposed work. 16. Construction Joints shall be located where shown or where approved by the Architect -Engineer. Construction joints in walls, beams and slabs shall be made by means of tight bulkheads at right angles to wall, beam or slab. Provisions shall be made for joining future work at all con- struction joints. Immediately after concrete is placed, projecting steel shall be cleaned and, before final set, horizontal surfaces shall be broomed or scraped clean of all laitance and scum where practicable. Before de- positing new concrete, the surface of the hardened concrete shall be broomed, roughened slightly, wetted and coated with neat cement paste or grout. New concrete shall be carefully rodded into grooves or recesses, around bars, plates and embedded items. 17. Expansion Joints shall be installed as indicated and shall extend entirely through the slab or between structural members. Exposed concrete slab edges shall be finished with an edging tool. Joint filler shall be nonextruding material conforming to ASTM Standard D 1751-65 or D 1752-60T. Joint between end of bridge and building shall be sealed with polyvinyl chloride multiple rib strips, with center bulb, not less than 3/16 -inch thick and six inches wide, W. R. Meadows, Inc., Type 6DS, or approved equal. 3-7 Waterstop material shall extend an equal distance each way from joint; shall be parallel to face of slab; and shall be secured rigidly in position by wiring to adjacent reinforcing steel at not more than 18 inches on center prior to placing concrete. Splices and intersections in waterstops shall be made by field fusing and welding as recommended by the waterstop manu- facturer to form a continuous watertight joint seal. a. Joint Sealing. Material shall be.cold applied, single component type conforming to requirements of Federal Specification SS -S -158a and similar and approved equal to "Presstite No. 67" or "Servicised Zero-Lastic Code 2377". Joints shall be prepared and sealing material shall be pressure machine applied in accordance with the sealing material manufacturers recommendations. 18. Finishing. Formed concrete surfaces not exposed to sight or weather need not be finished other than removal of lips, fins and ridges. Other surfaces shall be finished as follows: a. Exposed Formed Surfaces. After removal of forms, remove all ridges, lips and evidence of form joints; ream, chip and fill with nonshrink grout all honeycombs, voids and holes, including those re- sulting from removal of form rods and ties. Nonshrink grout shall be recessed and surface finished with mortar to match adjacent concrete as hereinafter specified. Remedy local bulging by tooling and rubbing. b. Lift Surfaces. Manipulation of concrete adjacent to the surface of any lift shall be the minimum necessary to produce not only the degree of consolidation desired in the surface layer of concrete, but also a surface with the desired degree of roughness for bond with the next lift. Surface vibration or excessive surface working, including screeding of any kind, will not be permitted. c. Trowel Finish. Floor slabs and interior stairs shall be struck off to accurately placed screeds spaced not over eight feet apart and tamped to force coarse aggregate away from surface. Concrete shall be screeded with straightedges and floated to a true and even surface, level or sloped to drain as shown. Excess water shall be drawn from surface with float; dusting with dry cement to absorb surface water will not be permitted. While concrete is still green but sufficiently hard to bear a man's weight without a deep imprint, concrete shall be floated to a smooth surface with no exposed aggregate and troweled to a burnished impervious finish. Edges, including those at joints, shall be finished with an edger or jointer. (1) Sealed Concrete. Concrete floors to remain exposed in completed construction and scheduled as "sealed concrete" shall receive one coat "Cem-Seal" as manufactured by Hillyard Chemical Co., or approved equal coating. Coating shall be applied in strict accordance with manu- facturers recommendations. d. Float Finish. Roofs, exterior platforms and stairs, tops of walls and similar surfaces shall be finished as specified for trowel finish except that final troweling may be omitted. Exterior platforms and stairs shall be finish brushed uniformly to obtain nonslip characteristics. 19. Curing. Concrete surfaces and at a temperature between 50 at least seven days following i as directed to compensate for t concrete falls below 50 degrees shall be subject to removal and the following alternate methods shall be maintained in a moist condition and 100 degrees F by adequate curing for aitial set. Curing period shall be extended Lme during which surface temperature of F. Concrete damaged by improper curing replacement as directed. Use of any of of curing shall not relieve the Contractor of his responsibility to obtain acceptable concrete having required strength and surface finish. a. Water Curing. Surface maintained continuously wet by sprinkling or by complete inundation. b. Earth or Sand Covering. 2 -inch covering maintained moist by water curing as above. L. Waterproof Paper Covering. ASTM Standard C 171-63. Concrete permitted to harden sufficiently to avoid marring surface. Thoroughly sprinkled immediately prior to placing paper. Edges of paper lapped at least 12 -inches, and secured in place to prevent opening of laps during curing period. d. Polyethylene Sheeting. Surfaces'shall be covered with white or translucent polyethylene sheeting not less than 0.004 inch in thickness. In the event that a continuous sheet is not used to cover the entire surface, edges and ends shall be lapped a minimum of four inches and sealed with approved adhesive tape. e. Forms Left in Place during any portion of the specified curing period shall be sprinkled and maintained moist only as required to prevent concrete from rapid drying. Of. Membrane Curing. Exterior slabs may be cured by use of approved type commercial curing compound, 20. Frost Protection. Concrete shall not be mixed or placed at ambient temperatures of 40 degrees F and less without adequate frost protection. Forms, reinforcing steel and subgrade shall be free from latent ice or frost. Aggregate or water, or both, shall be heated as required to permit placing of mixture at concrete temperatures ranging from 50 to 100 degrees F. If use of calcium chloride is approved, it shall be added completely dissolved in a portion of the mixing water and not more than two pounds per sack of cement shall be used. After placing, concrete shall be protected by suitable covering or heated enclosure to maintain the concrete temperatures within the above range during the entire curing period. If frost protection methods fulfill all requirements for curing, specified curing procedures may be omitted. M