WPC 22BS[!' #|d2cpi (J)Prestige Elite 12cpi (J)Prestige Elite 12cpi Bold (J)Prestige Elite 16.67cpi (J)Prestige Elite 12cpi (Math8) (J)HPLASEII.PRSdp@sQ,t0|a@#dp@sQ`@#26d Zl76#|dHP LaserJet Series IIHPLASEII.PRSdp@sQ,t0|a@pt Bold 12 pitch (D/J/M)Prestige Elite 12cpi (J)Prestige Elite 12cpi Bold (J)\( @,,,,0a2j h9 *2X R&tTddd,`dp@sQ@duSddd,dp,`vQQEHHH,7#^Hp@ƒQ^@B i-SQ&E% u%J-r+s3U<u-J;HvH+6** * * * * * * * * *  REMOVE THIS OUTLINE GUIDE BEFORE PLACING THE SPECIFICATION SECTION IN THE CONTRACT 6** * * * * * * * * * 'O U T L I N E G U I D E )DIVISION 3: CONCRETEă 'SECTION 03361 - SHOTCRETE USE:XFurnishing and applying reinforced and unreinforced shotcrete. Unique job requirements may require specific coverage in the following specification sections: (# X` hp x (#%'0*,.8135@8:GradationOGradation(#  Square Mesh hh* No. 1 88> No. 2 O No. 3 (#  (#   3/4 inchhh* ---88> ---O 100(#  1/2 inchhh* ---88> 100O 80-95(#  3/8 inchhh* 10088> 90-100O 70-90(#  No. 4hh* 95-100 88> 70-85O 50-70(#  No. 8hh* 80-10088> 50-70O 35-55(#  No. 16hh* 50-8588> 35-55O 20-40(#  No. 30hh* 25-6088> 20-35O 10-30(#  No. 50hh* 10-3088> 8-20O 5-17(#  No. 100hh* 2-1088> 2-10O 2-10(# h8@h x @@2. The sand shall be free from organic and deleterious materials. @@3. Lightweight aggregate shall be according to ASTM C 330. D.@@Compressed Air: The air used in shotcrete work shall be clean and free of oil and moisture.(#@ E.@@Welded-Wire Fabric: The size shall be [WWF 6 x 6 - W 3.5 x W 3.5] and shall be according to ASTM A 185.(#@ F.@@Reinforcing Bars: The bars shall be the sizes shown on the drawings, grade [40], according to ASTM A 615.(#@ G.@@Admixtures: Other than specified herein, or by reference, admixtures may be used only on written approval of the Contracting Officer.(#@ @@1.Admixtures shall be used in strict conformance with the manufacturer's written instructions.(# @@2. The use of microsilica is recommended to reduce rebound. #0*%% H.@@Membrane Curing: Liquid membrane-forming curing compounds shall be according to ASTM C 309.(#@ I.@@Sheet Covering: Materials shall be according to ASTM C 171.(#@ 2.02 EQUIPMENT: A. Air Compressor: @@1.Shall be capable of supplying clean, dry air at rates and pressure which will maintain sufficient nozzle velocity for adequate compaction of the shotcrete regardless of elevation differences and distance between the various components. The air compressor shall be designed and equipped to supply oil-free air.(# @@2.Compressor shall be capable of simultaneous operation of a blow-by pipe for cleaning the surface being shotcreted and clearing away rebound.(# @@3.Accumulation of hardened materials in the delivery equipment will not be permitted.(# B.@@Batching Equipment: Provide an onsite batch-type mixing plant or volumetric batching and continuous mixing plant.(#@ @@1.The equipment shall be capable of combining the aggregate, cement, water and admixture into a uniform mixture and discharging this mixture without segregation.(# @@2.Facilities shall be provided for the accurate measurement and control of each of the materials entering the shotcrete.(# @@3.The complete assembly shall include provisions to facilitate the inspection of operations. (# @@4.Government inspectors shall have free access to the batching and mixing plant. (# @@5.Accumulation of hardened materials in the batching and mixing plant will not be permitted.(# 2.03 MIXES: A.@@Shotcrete: The basic mix shall contain 7 sacks of portland cement to each  tT! yd3 of sand.(#@ B. Slurry Plaster: Shall consist of 3 parts sand to 1 part portland cement. $ 0*%% C.@@Moisture Content: The aggregate shall be such that, when mixed with cement, the mixture shall flow at a uniform rate through the delivery hose and work readily into corners and angles of forms and around reinforcement. Materials shall not be allowed to segregate or excess free water to collect on the surface. The optimum moisture content will depend upon the equipment being used, but will generally be between 3% and 6% by weight.(#@ D.@@Compressive Strength: Shall be 2,500 psi at 7 days and 4,000 psi at 28 days.(#@ PART 3: EXECUTION 3.01 PREPARATION: A.@@General: Preparation work shall be according to ACI 506.2, except as noted.(#@ B. Surface Preparation: @@1.Surfaces to receive shotcrete shall be prepared by removing vegetation, loose soil and rock fragments, and grubbing out roots. Preparation shall be accomplished with equipment and methods which do not loosen, crack, or shatter surfaces to receive shotcrete. Material loosened or damaged during surface preparation shall be removed to provide a base sufficiently stable to receive shotcrete. Sides of depressions resulting from removal of roots and embedded rock fragments shall be shaped as required to ensure complete filling with shotcrete. Surfaces shall then be given a preliminary clean-up with high pressure air jets to facilitate inspection by the Contracting Officer. If additional surface preparation is then needed, the surface again shall be prepared and cleaned.(# @@2.Waste from surface preparation shall be placed adjacent to the work site and removed, and according to the applicable provisions of local, state, and federal regulations.(# @@3.Surface to receive shotcrete shall, where practicable, be free of water when shotcrete is applied. Suitable weep holes, relief pipe, or other methods of controlling water inflows shall be provided.(# @@4.Where impracticable to control free water, shotcrete may be applied to such surfaces provided the shotcrete adheres readily to the surfaces and prevents the inflow of water through the shotcrete.(# @@5.The Contractor may provide and use plastic tubes to collect and drain inflows. The plastic tubes may be left in place and embedded in shotcrete.(# @@6.Soil surface shall be kept damp for a minimum of 4 hr prior to the application of shotcrete.(#$ 0*%%Ԍ 0*%% @@7.Remove, by chipping or grinding, material that is loose or unsound, and radius corners which cause abrupt changes in the surface plane of concrete, masonry, and rock surfaces. Taper edges of surface cavities. After obtaining approval of the surface preparation, the surface shall be wet sandblasted or water blasted to remove contaminants and to provide a roughened surface. Water blasting equipment shall be capable of delivering water pressures of 7500 psi. Adjust water pressure based on surface conditions. Dampen the surface for a minimum of 2 hr immediately before shotcreting.(# C.@@Embedded Items: Secure accurately and permanently in place before placing shotcrete. Allow one working day for inspection and approval by the Contracting Officer of embedded items, including reinforcement before shotcrete placement. Notify the Contracting Officer 24 hr prior to the time that the embedded items are prepared for inspection.(#@ D.@@Forms: Complete formwork and obtain inspection and approval before placing shotcrete.(#@ @@1.Forms shall be structurally sufficient and of such design that rebound or accumulated loose sand can freely escape or be readily removed.(# @@2.Surfaces of forms to be in contact with shotcrete may be coated with a release agent.(# @@3.Forms shall keep shotcrete to within [ ] inches of design dimensions.(# E.@@Shooting Strips: Shall be used at corners, edges and on surfaces where necessary to obtain true lines and proper thickness.(#@ F.@@Metal Culverts: Shall be cut off flush with the finished surface of the shotcrete liner.(#@ @@1.Burnback of galvanized surface [in excess of 3/8-inch] shall be treated with one coat of zincrich paint.(# 3.02 PLACING REINFORCEMENT: A.@@General: Reinforcement shall be free of loose flaky rust, mud, oil or other coatings that will destroy or reduce the bond where shotcrete is placed.(#@ B.@@Wire Fabric: Lap splices one full square of mesh and wire securely at onefoot intervals. Support and anchor as shown on the drawings.(#@ C.@@Reinforcement Bars: Lap bars according to the CRSI Manual of Standard Practice. Support and anchor as shown on the drawings.(#@ $ 0*%% D.@@Cover: Wire fabric shall be located [1-1/2] inches below the surface of the shotcrete.(#@ E.@@Bondbeam: Welded wire fabric shall extend into the bond beam, bent around and wired to itself as shown in the drawings.(#@ 3.03 MIXING: A.@@General: Mixing may be accomplished by either a wet mix delivery process or drymix delivery process.(#@ @@1.Cement and fine aggregate shall be thoroughly mixed before being charged into the machine.(# @@2.The mixer shall be cleaned at regular intervals (at least once every 8-hour shift) and thoroughly enough to remove adherent material from the mixing valves and drum.(# @@3.The equipment shall be kept clean and in an operating condition ready for use during the work.(# @@4.The Contractor shall ensure that adequate air and water is supplied to the machine as specified by the equipment manufacturer. (# @@5.The equipment shall be such that rapid-hardening admixture, if used, can be added and mixed satisfactorily at the gun.(# @@6.The mixing time shall be contingent on the equipment as recommended by the manufacturer. (# B.@@Wet Mix Delivery Process: After completion of mixing, the mix shall be metered into a delivery hose and conveyed by compressed air to the nozzle.(#@ C. Dry Mix Delivery Process: @@1.Moisture content of the fine aggregate shall be carefully controlled to prevent clumping of the dry mix and help insure that the mix will flow through the delivery hose at a uniform rate without lumps of concentrated shotcrete.(# @@2.The equipment shall be capable of delivering the premixed materials accurately, uniformly and continuously through the delivery hose at a velocity of at least 500 fps. (# @@3.The discharge nozzle shall be equipped with a manually operated water injection system (water ring) capable of evenly distributing water through the delivered mixture. The water nozzle shall be capable of ready adjustment.(#$ 0*%%Ԍ@@4.Aggregate, cement and dry admixture shall be dry mixed, with the water and accelerator agent being introduced at the gun.(# 3.04 PLACING SHOTCRETE: A. General: @@1.Acceptable shotcrete shall be dense and uniform and without discernable weakness of bond between layers.(# @@2.Shotcrete equipment shall be arranged so that the nozzleman can use air and water in combinations for preparing surfaces to receive shotcrete.(# @@3.Surface shall be cleaned with high pressure air jets immediately prior to applying shotcrete.(# B. Nozzle: @@1.Velocity must be maintained at a uniform rate determined for a given job condition to produce minimum rebound.(# @@2.Position shall be held in a position and distance so that the stream of flowing material shall impinge at approximately right angles to the surface being covered to produce a spreading effect over a small area.(# C. Placement: @@1.The minimum thickness of shotcrete placed shall be [ ] inches.(# @@2.Shotcrete shall be built up in a series of layers, not exceeding 2 inches thick, using a slightly wetter mix for the first coat of each layer followed by one or more drier coats applied while the first layer is still plastic.(# @@3.When shotcrete is to be applied near existing structures, the Contractor shall ensure that no damage results to the structure and shall protect the surface of the structure before shotcreting begins.(# @@4.Nails, pins, or other gauging devices shall be installed in the surface of the weak layer to demonstrate that the required minimum thickness of shotcrete has been placed.(# @@5.The nozzleman shall shoot shotcrete with a uniform consistency and at the wettest consistency short of the sag point.(# (#0*%% @@6.If the shotcrete mix flow becomes intermittent the nozzleman shall divert the stream away from parts of the area being or to be shotcreted until the flow becomes consistent.(# @@7.The mix stream shall be angled as required to ensure complete encasement of plastic tubes installed to collect and drain water inflows. (# @@8.Tubes may be capped temporarily to prevent plugging when the shotcrete is applied to the immediate area.(# D. Placement Around Reinforcement: @@1.Hold the nozzle at such distance and angle to place material behind reinforcement before material is allowed to accumulate on its face.(# @@2.Shotcrete to embed wire fabric will not be considered complete until the shotcrete layer has been built up to the thickness specified and until the wire mesh and supporting bolts are completely covered with shotcrete to a depth of at least [ ] inches.(# E. Rebound Sand: @@1.Rebound or accumulated loose sand shall be removed from the surface to be covered prior to placing of the original or succeeding layers of shotcrete.(# @@2.A separate air hose and blowpipe shall be used to remove dust and rebound during shotcrete operations.(# @@3.Rebound material shall not be re-used.(# F. Joints: @@1.Shotcrete at the end of a days work or similar stopping periods shall be sloped off to a 45degree angle.(# @@2.Before placing an adjacent section, sloped portions shall be thoroughly cleaned and wetted.(# G. Bond: @@1.Surfaces to which shotcrete or slurry is to be bonded shall be thoroughly cleaned of dirt, grease, organic matter and loose particles.(# @@2.Absorptive surfaces shall be wetted before the application of shotcrete.(# #0*%% H.@@Bond Beam: A [6inch x 6-inch] shotcrete bond beam shall be constructed around the perimeter of the lining [as shown on the drawings].(#@ I. Slurry Plaster: @@1.The entire shotcrete surface shall be coated with a slurry plaster consisting of a sand-cement mix specified in the Mixes article in Part2.(# @@2.The minimum thickness shall be 1/8inch.(# @@3.Slurry plaster shall not be applied prior to the initial set of the shotcrete.(# 3.05 FIELD QUALITY CONTROL: A.@@Testing: [The Government will perform the required testing, recording, and distributing of the results.] [The Government will make arrangements for a certified independent testing laboratory to perform the required testing, recording, and distributing of the results.] [The Contractor shall conduct the performance and acceptance tests of the [_____________________________(#@ @@______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________.](#@ @@The Contractor shall furnish necessary equipment, labor, and materials to conduct the testing. Testing shall be conducted in the presence of the Contracting Officer.] [The Contractor shall make arrangements for a certified independent testing laboratory, according to the requirements of Section 01410 Testing Laboratory Services, to perform the required testing, recording, and distributing of the results.] The Contractor shall pay for extra cylinders and tests required for cold weather or form stripping control purposes. The Contractor shall also pay for additional tests during pours that are required due to apparent changes in the concrete mix or in the concrete placing operation.](#@ B.@@Site Storage: The Contractor shall provide a wooden box for safe storage of test cylinders and test panels at the project site. Cylinders and panels shall be stored in the box for 24 hr before being transported to the testing facility.(#@  0*%%  tT C.@@Frequency: At least one set of samples shall be taken for each 35 yd3 of  tT shotcrete placed or each day shotcrete is placed if less than 35 yd3 are placed.(#@ @@1.Compression and strength tests for wetmix delivery process shall consist of 4 standard 6-inch diameter by 12-inch cylinders. Two cylinders shall be tested at 7 days and 2 at 28 days. Samples shall be according to ASTM C 172. Samples shall be made and cured according to ASTM C 31 and tested according to ASTM C 39.(# @@2.Compression and strength test for drymix delivery process sample shall consist of two 16inch x 30inch x 3inch test panels. Samples from each panel shall be tested at 7 days and 28 days. Panels shall be according to ACI 506.2. Panels shall be cured according to ASTM C 31. Samples will be obtained from test panels according to ASTM C 42 and tested according to ASTM C 39.(# @@@h x@` ( Xa.` ` Test panels shall be obtained by securely attaching an approved 16inch x 30inch x 3inch deep box with rigid base to an area similar to that to be shotcreted or on an alternate surface approved by the Contracting Officer. The box shall be wetted and shotcrete applied to the area contained by the box in the manner specified in the Placing Shotcrete article in Part 3, and using the same mixing and placing equipment.(#` @@b.` ` Test box shall be constructed with 3/4inch CDX plywood bottom and 2-inch x 4-inch wood or larger sides. Two sides perpendicular to the slope shall be left open.(#` D.@@Shotcrete Quality: Shall be based on an average of three 28-day tests or two 28-day tests if a 7-day break is requested.(#@ @@1.Where the testing laboratory reports on breakage of cylinders or cores show shotcrete does not comply with specifications, the Contracting Officer may request further testing of shotcrete to determine strength of in-place shotcrete. Such further testing shall be obtained and the Contractor shall pay for such further testing.(# E.@@Deficiencies: The Contracting Officer will indicate areas of rejected shotcrete.(#@ 3.06 FORM REMOVAL: A.@@General: Forms shall remain in place for time recommended according to ACI 347, Article 2.7.(#@ @@1.Remove forms with care to avoid damage to shotcrete.(# $0*%%Ԍ@@2.Remove fins and protrusions flush to surface.(# @@3.Remove loose material.(# 3.07 DEFICIENCY CORRECTION: A.@@Inspection: Before a succeeding layer of shotcrete is placed, the preceding layer shall be checked for drumminess indicating voids or lack of adhesion to the satisfaction of the Contracting Officer.(#@ B.@@Repairs: The Contractor shall repair drummy, sandy, cracked or spalled areas and other areas where the shotcrete is faulty, by removing the shotcrete to a sound area, carrying out surface preparation as specified in article 3.01 and reshooting that area according to these specifications or by adding depth as approved by the Contracting Officer.(#@ 3.08 FINISHING: A.@@Normal Finish: Unless otherwise specified, provide natural gun finish throughout.(#@ B.@@Troweling: Avoid troweling of thin sections of shotcrete unless both troweling and commencement of moisture curing take place within a relatively short period after placement of shotcrete. Do not, in any case, scrape or cut to remove high spots until the shotcrete has become stiff enough to withstand pull of the cutting devices.(#@ 3.09 CURING: A.@@Curing: When dry specks first appear at the surface of a shotcrete layer, it shall be wetted with a water spray at least once each 4 hr or covered with an approved curing compound or moisture-proof covers.(#@ 3.10 CLEANING: A.@@Spilled Shotcrete: Remove prior to its final set from surfaces including reinforcing wire to be embedded in a future pour.(#@ B. Forms and Materials: Remove and leave project site clear of debris. 3.11 PROTECTION: A.@@Requirements: Shotcrete shall be applied, protected, and cured to prevent its temperature falling below 50 degrees F, or a loss of moisture from the surface for the periods indicated below:(#@ @@1.Normal portland cement: 7 days.(#@ $0*%%Ԍ@@2.High early-strength portland cement: 3 days.(#@ PART 4: MEASUREMENT AND PAYMENT 4.01 METHOD OF MEASUREMENT: A.@@Units: The work described in this section will [not be measured for payment.] [be measured and paid for] [on a lump sum basis.] [by the cubic yard of shotcrete applied.] [by the square foot of] [slurry plaster applied.] [reinforcing wire installed.](#@ 4.02 BASIS OF PAYMENT: A.@@Payment: [No direct payment for the work described under this section will be made. The Contractor shall include consideration for this item in the bid price for other items of the Contract.] [Prices and payment will be full compensation for the work described in this section. Payment will be made under:](#@ @@ Pay Item !=BDXXF Pay Unit(#X @@03361(01) Shotcrete. . . . . . . . . . . . . . . . . . . . . Lump Sum(#@ @@03361(02) Shotcrete. . . . . . . . . . . . . . . . . . . . . Cubic Yard(#@ @@03361(10) Slurry Plaster . . . . . . . . . . . . . . . . . . Square Foot(#@ @@03361(20) Reinforcing Wire . . . . . . . . . . . . . . . . . Square Foot(#@ 0,END OF SECTION