725 679.2.2.1 -Latex Modified Concrete: The following test criteria must be met for all latex modified concrete pours placed at the structure. This testing shall be performed by the Contractor or his designated representative and certified results provided to the Engineer prior to final acceptance of the project.
Table 679.2.2.1 Chloride Permeability (a) 1000 coulombs @ 90 or 180 days, maximum (per AASHTO T 277) Compressive Strength (b) not less than 80% of 28 -day compressive strength of the approved test mix Water/Cement Ratio (c) 0.40 by weight, maximum Portland Cement Content 658 lb/cu. yd., minimum Latex Admixture Content (d) 24.5 gal/cu. yd., minimum Air Content (e) 6.5% maximum (Per AASHTO T 152) Slump 4.0 inches ± 2.0 inches
Note (a) When required, as outlined in the Contractor’s Quality Control Section of Section 679.2.2, rapid chloride permeability tests shall be performed and the results tabulated and submitted to the Engineer. Chloride permeability of the in -place concrete shall b e considered acceptable if the 28 -day compressive strengths obtained in Section 679.2.2 are greater than eighty percent (80%) of the 28 -day compressive strength of the approved test mix. If the compressive strength requirements noted in Table 679.2.2.1 are not satisfied, and the permeability value noted in the Table 679.2.2.1 is exceeded, then the concrete represented by these strength and permeability values may be removed and replaced by the Contractor. If the Contractor elects to leave the material in p lace, the Engineer shall evaluate it as to the adequacy for the use intended. All concrete evaluated as unsatisfactory for the use intended shall be removed and replaced by the Contractor. When the Engineer’s evaluation indicates that the work may satisf actorily remain in place, the subject material shall be paid for at a reduced unit price based on Table 679.2.2. 2B. Note (b) The minimum compressive strength for the overlay concrete shall be 80% of the 28 -day compressive strength of the approved test mix. However, the minimum 28 -day compressive strength shall be 4,000 psi. Overlay concrete with a compressive strength of less than this acceptance level may be removed and replaced at the contractor’s expense. Note (c) The amount of added water shall be adjusted to provide slump at or below the prescribed limit. The water portion of all admixtures shall be included as part of the water/cement ratio. Note (d) Latex sampling shall be in accordance with 707.5. Note (e) The initial mix design shall be base d on an expected air content range of 3% to 6%. The mixture proportions shall be determined using actual conditions for fineness modulus and bulk specific gravities (saturated surface dry for aggregates).
726 679.2.2.2 -Silica Fume Concrete: The following test criteria must be met for all silica fume concrete pours placed at the structure. This testing shall be performed by the Contractor or his designated representative and certified results provided to the En gineer prior to final acceptance of the project.
Table 679.2.2.2 A Chloride Permeability (a) 1000 coulombs @ 90 days or 180 days, maximum (per AASHTO T 277) Compressive Strength(b) not less than 80% of 28 -day compressive strength of the approved test mix Water/( Cementitious Materials) Ratio (c) 0.37 by weight, maximum Portland Cement Content (d) 680 lb/cu.yd., minimum Silica Fume Content (e) (Dry Weight) 50 lb./cu. yd., minimum Air Content 7.0% (plus or minus 1.5%) (Per AASHTO T 152) Slump 6.5 inches ± 1.5 inches High Range Water Reducer
water/cementitious ratios
Note (a) When required, as outlined in the Contractor’s Quality Control Section of Section 679.2.2, rapid chloride permeability tests shall be performed and the results tabulated and submitted to the Engineer. Chloride permeability of the in -place concrete shall b e considered acceptable if the 28 -day compressive strengths obtained in Section 679.2.2 are greater than eighty percent (80%) of the 28 -day compressive strength of the approved test mix. If the compressive strength requirements noted in Table 679.2.2.2 are not satisfied, and the permeability value noted in the Table 679.2.2.2 is exceeded, then the concrete represented by these strength and permeability values may be removed and replaced by the Contractor. If the Contractor elects to leave the material in place, the Engineer shall evaluate it as to the adequacy for the use intended. All concrete evaluated as unsatisfactory for the use intended shall be removed an d replaced by the Contractor. When the Engineer’s evaluation indicates that the work may satisfactorily remain in place, the subject material shall be paid for at a reduced unit price based on Table 679.2.2. 2B. Note (b) The minimum compressive strength for the overlay concrete shall be 80% of the 28 -day compressive strength of the approved test mix. However, the minimum 28 -day compressive strength shall be 4,000 psi. Overlay concrete with a compressive strength of less than this acceptance level may be removed and replaced at the contractor’s expense. Note (c) The amount of added water shall be adjusted to provide slump at or below the prescribed limit. The water portion of all admixtures shall be included as part of the water/cement ratio. Note (d) An equal volume of fly ash may be substituted for cement to a maximum of 1 ¼ bags per cubic yard. An equal volume of slag cement may be substituted for cement to a maximum of 3 bags per cubic yard. When fly ash or slag cement are used, equivalent volu mes of fly ash or slag cement shall be considered as cement for purposes of determining the proportioning ratios. Note (e) Silica fume sampling shall be in accordance with 707.4.3. Note (f) A high range water -reducing admixture is required to improve workability. No more than two additions of the admixture shall be made, and the total quantity shall not exceed the manufacturer's maximum dosage rate. Each time high range water reducer is added, the concrete shall be mixed an additional minimum of 30 revolutions. The total number of revolutions shall not exceed 300.
727 Table 679.2.2. 2B Permeability result obtained in Table 679.2.2.1 or 679.2.2.2 A. See Note (a) (values expressed in Coulombs) Percent of unit bid price paid according to Section 679.6.3 which will be paid for material in question >1,000 – 1,500 95% >1,500 – 2,000 90% >2,000 – 2,500 85% >2,500 – 3,000 80% >3,000 – 3,500 70% >3,500 – 4,000 60% >4,000 Remove and replace
679.2.2.3 -Pre-Pour Meeting: The Contractor shall schedule a meeting prior to the start of the concrete work. The Engineer, Construction Manager, Prime Contractor, Concrete Contractor, Concrete Finisher, the Concrete Supplier and the Individual or Agency that will perform the qualit y control testing of the concrete shall attend. Topics of discussion shall include specialized concrete mixture proportions, batching, transporting, handling, placing, finishing and curing.
679.2.2.4 -Test Slab Requirements: After obtaining the Enginee r's approval of mixture proportions and at least one week before any slab reconstruction concreting or overlay is to be placed, the Contractor shall make one or more trial batches of the specialized concrete of the size to be hauled or mixed at the site. The trial shall simulate transportation and job site conditions, utilizing proposed material and methods of placing, finishing, and curing, including the application of bonding grout when required. The test slab shall be constructed the same as the actual work (depth, reinforcing steel, etc.) and shall be at least one lane width wide and of a length to allow the use of the contractor’s entire paving train from placement to finishing. The test slab location shall be as shown in the plans or as approved by th e Engineer. The prime intent is to familiarize the concrete finishing crew with the handling, finishing and curing characteristics of the concrete. Batching, placement and texturing shall be in strict accordance with this specification. Additional refere nce test slabs may be constructed as necessary to provide an acceptable standard of reference. This standard of reference shall serve throughout the project construction period as the basis of acceptance of the actual as -built work. This Item may be deleted at the discretion of the Engineer.
679.2.3 -Equipment: All equipment proposed for use shall have the Engineer's approval prior to its usage.
679.2.3.1 -Cutting Equipment: Shall consist of a high pressure water jet
679.2.3.1 .1-Hydrodemolishing Equipment: The hydrodemolishing system shall be self-propelled, completely programmable, designed for high production concrete removal, and capable of removing precise depths of sound concrete. Hyd rodemolishers shall be
728 capable of removing concrete from around and below the steel reinforcement. Lances shall be of a type intended to remove rather than scarify concrete. Individuals certified by the equipment manufacturers shall operate the removal equ ipment. All removal equipment shall be capable of operating at a noise level of less than 90 decibels at a distance of fifty ( 50) feet from the noise source. The Contractor shall monitor noise levels throughout the project to insure compliance, if required by the Engineer. No separate or additional payment will be made for monitoring -noise levels. Potable or filtered water may be used. Filtered water shall have all visible solids and oils removed that could prevent a proper bonding with the remaining concrete. When filtered water is used, the Contractor shall wash the bridge deck with potable water in water blasting equipment as so on as all the concrete debris has been cleaned up. This water blasting shall be in addition to any other water blasting that may be required. The Contractor shall shield his operations to prevent injury or damage from flying or falling debris. The Contrac tor shall provide a method for handling expected and unexpected blow -through of the deck. This method shall provide for the containment of runoff water and debris, and the protection of the area under the bridge deck. The Contractor shall be responsible fo r any injury or damage caused by his operations.
679.2.3.1 .2-Hydrodemolishing Equipment Demonstration: Two trial areas will be designated by the Engineer to allow the Contractor to demonstrate that the equipment, personnel, and methods of operation can meet the requirements of this specification. The demonstration shall follow any roto -milling permitted by this specification. No separate or additional payment will be made for this demonstration. The first trial area will consist of approximately 30 squa re feet of sound concrete. The hydrodemolisher shall be calibrated to remove sound concrete to the depth specified in the contract documents without damaging the underlying sound concrete. After removing the sound concrete in the first trial area, the hydr odemolisher shall be moved to the second trial area. This area will consist of deteriorated or defective concrete. This trial will determine whether this unsound concrete will be completely removed with the above calibration. If the equipment is deemed in adequate for use, the Contractor shall obtain another hydrodemolisher for a subsequent demonstration. When satisfactory results are obtained, production removal may proceed. No adjustment in the completion date of the project will be considered due to dela ys in obtaining suitable equipment. If concrete is not being adequately removed during production work, recalibration of the equipment will be required.
679.2.3.2 -Blastcleaning Equipment: Blastcleaning Equipment shall be capable of removing rust from r einforcing bars, laitance, and small chips of partially loosened concrete. Certain qualities of rust are not necessary to be removed (refer to Section 679.3.3).
679.2.3.3 -Proportioning and Mixing Equipment: Handling, Measuring, and Batching of materials shall conform to the requirements specified in 501.7. Proportioning and Mixing Equipment shall consist of the following:
679.2.3.3 .1-Latex Modified Concrete: Self-contained, continuous mixing and proportioning mobile units shall be used. A minimum of two units shall be supplied. The requirements of Sections 679.2.3.4 and 679.2.3.5 shall apply.
729 679.2.3.3.2 -Silica Fume Concrete: An approved concrete batch plant, mobile mixer or truck mixer shall supply all concrete. The requirements of Section 601 of the Specifications shall apply, except as modified herein. When silica fume densified powder is used, the densified powder shall b e weighed using an approved cement scale or supplied in bags, the weight of each bag shall be clearly marked on the bag. The densified powder shall be last in the weighing sequence and the tolerance for each material draw weight shall be based upon the total weight of cement plus densified powder. Batching tolerance for the cement plus densified powder shall be 1%.
679.2.3.4 -Mobile Mixer Units: Each unit shall be self -propelled and shall be capable of carrying sufficient unmixed material to produce on site, no less than 6 cubic yards of specialized concrete. Volumetric mixers shall conform to the requirements of AASHTO M 241, except as otherwise specified. The Engineer will inspect each unit. A unit not functioning in a manner the Engineer considers a cceptable shall be repaired. If repair is impractical, the unit shall be replaced. All costs associated with delays attributable to mobile mixer replacement shall be borne by the Contractor. No extension of time, for the purpose of replacing unacceptabl e mixers, will be granted. Conditions which will automatically designate a unit unacceptable are: hydrated cement deposits; broken, bent, loose or scalloped mixing paddles; mixing paddles worn 20% in any dimension; mixing paddles heavily caked with mortar ; and admixture or water delivery system out of tolerance. Proportioning devices shall deliver the materials within the following tolerances:
Coarse Aggregate ±2% Fine Aggregate ±2% Cement + fly ash 0% to +4% Water ±1% Cement + silica fume powder 1% Latex Admixture 1% Other Admixtures 3%
The unit shall be capable of positive measurement of cement being introduced into the mix. There shall be positive control of the flow of water into the mixing chamber. Water flow shall be indicated by a flowmeter and readily adjustable to provide for minor variations in aggregate moisture. The system shall be equipped with a bypass valve, or hose, for determining proportioning accurately. Also, there shall be a positive control of the flow of admixture into the mixing chamber. The admixture discharge pipe shall be readily accessible for determining proportioning accuracy. The units shall be capable of being calibrated to automatically proportion and blend all components of indicated compo sition on a continuous or intermittent basis as required by the finishing operation, and shall discharge mixed material through a conventional chute directly in front of the finishing machine. A sufficient number of self -propelled mixers shall be availabl e at the job site to insure that not more than 30 minutes shall elapse between the placement of batches.
730 679.2.3.5 -Mobile Mixer Unit Testing: The units shall be calibrated by the Contractor to accurately proportion the approved mix design prior to placi ng the mix. The Engineer may require recalibration of any mixer as deemed necessary. Yield tests shall be performed by the Contractor for each mixer for each day's operation and when there appears to be a change in the mix. Certification of the calibrati on by an approved testing authority will be accepted as evidence of this accuracy if the yield is shown to be true within a tolerance of 1.0% according to the following test: With the cement yard set on zero and all controls set for the approved design mi x, activate the mixer and discharge mixed material into a 0.25 cubic yard container 1 yard square by nine ( 9) inches tall. When the container is level -struck full, making provision for settling the material into all corners, the cement yard shall show the discharge for a 0.25 cubic yard pour within the tolerance specified (refer to 679.2.3.4). No calibration shall be performed while it is raining.
679.2.3.6 -Placing and Finishing Equipment: This shall include adequate hand tools for the placement of plastic concrete and for working down to approximately the correct level for the auger strike -off. A self -propelled finishing machine will be required to place and finish all concrete, except i n areas inaccessible to the machine. The finishing machine shall be capable of forward and reverse motion under positive control. Provisions shall be made for raising the screeds to clear the screeded surface, if traveling in reverse. The machine shall b e capable of placing full width, in one operation, the pours shown in the plans. The finishing machine shall be equipped with a vibrating device to consolidate the concrete, a power driven strike -off auger, a power driven finishing roller, and a pan float . The vibrating device shall vibrate at a frequency between 50 Hz and 115 Hz. A sufficient number of suitable portable lightweight or wheeled work bridges shall be required and used behind the finishing operation for touch -up work, surface texturing and c uring cover placement. Approved manual type screeds, metal plates equipped with electric vibrators, or hand held vibrators shall be used to consolidate and finish small inaccessible areas and slab reconstruction concrete. Supporting rails shall be requi red. Rails may be two (2) inch by two ( 2) inch perforated steel bar stock, two ( 2) inch pipe rail, or approved equal. They shall exhibit no bends or kinks. Rail supports shall be fully adjustable (not shimmed) to obtain the correct profile. Rail supports are subject to the requirements of 679.3.7.2. When placing concrete adjacent to a previously completed pour, the side of the finishing machine adjacent to the completed pour shall be equipped to travel on the completed lane on rail supports only. The placing and finishing equipment shall be designed so that the elapsed time between depositing concrete and final finishing shall not exceed 10 minutes.
679.2.3.7 -Recording Thermometer: The Contractor shall supply a continuous recording thermometer ca pable of recording temperatures in the 30 - 150 F range. It shall likewise provide a recording capability over a 24 -hour continuous period, minimum. The Contractor shall provide any ancillary equipment, supplies and labor necessary for calibration of this equipment.
731 679.2.3.8 -Compressors Or Water Flushing Equipment: Equipment used for surface preparation shall be of such size and capacity to thoroughly remove all foreign material from the surface being prepared.
679.2.3.9 -Saw Cutting Equipment: Only multi -bladed saw cutting equipment, using circular saw blades, will be permitted for final deck finish operations. The Engineer may allow the use of single blade circular saw equipment only where such equipment is necessary to complete the work as required.
679.2.3.1 0-Fogging Equipment: Fogging equipment shall be available for use in accordance with these specifications. The fogging nozzles shall produce an atomized mist. Fogging nozzles shall incorporate compressed air to create the mist. Hand held o r hand operated equipment shall be permitted when the Contractor has demonstrated that his operator has been trained in its use.
679.3 -CONSTRUCTION METHODS : 679.3.1 -Removal of Existing Deck Surface: All asphaltic patches or bituminous overlays shall be removed by hydrodemolishing, roto -milling, or other approved methods. All debris from patch or overlay removal shall be legally disposed. Unless otherwise dir ected by the engineer, prior to concrete deck removal operations, the Contractor shall sound the deck using chain drags.
679.3.1.1 -Removal of Existing Deck Surface Phase I: The Contractor shall determine the depth to the top mat of reinforcing steel using methods acceptable to the Engineer. The existing deck shall be removed so as to expose the topmost components of rebar in the upper mat of reinforcement. Full exposure of t he upper mat of reinforcement is not required. The deck removal shall be accomplished by roto -milling, hydrodemolishing, or any means acceptable to the Engineer. After removal of the deck is complete as described above, the Contractor shall sound the de ck using chain drags and delineate remaining areas of delaminated and unsound concrete for removal subject to the approval of the Engineer. Aerosol spray paint for delineating shall be provided by the Contractor. Edges around these concrete removal areas shall be vertical or slightly undercut. Upon completion of removal, the Contractor shall provide a hydrodemolished surface on which to install the new concrete Overlay. When full depth removal of material is necessary, the forming shall be performed in accordance with Sections 104.3 and 109.4 of the Specifications.
679.3.1.2 -Removal of Existing Deck Surface Phase II: Unless waived by the Engineer, immediately prior to placement of new concrete overlay, the Contractor shall sound the deck using chain d rags and delineate any additional areas that may have become delaminated or unsound. Edges around these concrete removal areas shall be vertical or slightly undercut. These areas shall be removed prior to placement of the new concrete overlay. The Div ision is not responsible for delays caused by the concrete removal described here in 679.3.1.2. When full depth removal of material is necessary, the forming shall be performed in accordance with Sections 104.3 and 109.4 of the Specifications.
732 679.3.1. 2.1-Full Depth Removal of Material: When full depth removal of material is necessary it shall be handled in accordance with section 679.6.2.3.
679.3.1.3 -Use of Chipping Hammers: When encountering locations of delaminated and unsound concrete that need to be removed but not easily accomplished or accessible as described in sections 679.3.1.1 and 679.3.1.2, chipping hammers may be used when permitted by the Engineer to remove concrete.
679.3.1.4 -Disposal: Debris shall be removed directly following any concrete removal operations. Removal of debris shall be accomplished by hand and vacuum methods. All debris shall become the property of the Contractor and shall be legally disposed. The Contractor shall exe rcise care to avoid damage to the remaining concrete or exposed reinforcement. The Contractor shall provide for the collection, treatment and/or disposal of all runoff water generated by the removal process. The Contractor will provide the Engineer with evidence and documentation of disposal means and/or that any discharge does not exceed water quality standards. No payment for item 679001 Concrete Deck Overlay will be made until the Engineer receives evidence of satisfactory disposal and/or treatment. Should the disposal and/or discharge of material occur within the State’s Rights -Of-Way without satisfactory evidence of maintaining the current water quality standards, the Engineer will have the authority to suspend the work wholly or impart as described in section 105.9. The Contractor shall obtain all required permits and shall comply with applicable local, state, and federal regulations concerning such water disposal. The Contractor shall make provision for the safe handling of runoff water insofar as it may constitute a physical hazard on the adjacent or underlying traveled roadway surface. Water will not be allowed to enter storm sewers, bridge drainage, downspouts, fingerdams, or any other drainage area of the deck surface. The Contractor shall exe rcise care to protect existing berm slopes from scouring by water jets or runoff water. In addition to the requirements mentioned above, to temporarily discharge wastewater from activities associated with hydroblasting demolition of concrete on a bridge d eck. The wastewater shall be treated prior to discharging to natural drainage. The authorization being granted herein is contingent upon strict adherence to the following conditions.
Environmental Protection (DEP) with carbon copies to the WVDOH personnel as listed in the plan notes, the following information for review:
location, Contractor’s Name, descr iption of work, description of discharge, a list of Best Management Practices to be used to protect water quality, and estimated start & stop dates of discharging activity.
The Contractor will allow the DEP seven (7) days to review the submitted information and respond.
the initiation of the work activities.
mitigate any adverse impacts re sultant to the temporary discharge occurrence.
733 c) Collected solids shall be disposed of in a manner consistent with any, and all, appropriate laws and regulations.
provide for the maximum alleviation of impact to, and maximum protection of, aquatic life and human health.
District field office, 24 hours prior to the initiation of any procedures. This wi ll afford the DEP with an opportunity to have personnel available to observe the activities.
1-800-642-3074 in the event of an accidental discharge that did not go through the appropriate devices.
679.3.15-Miscellaneous: The Contractor shall provide adequate lighting to allow for
the safe conduct of night removal operations, and shall obtain the Engineer's approval for same, exercising care to avoid any hazardous glare in the direction of oncoming traffic.
679.3.2 -Removal of Newly Placed Deck Surface: The finished deck surface shall be shotblasted in preparation for a mechanically bonded surface. Burlap shall be continuously wet for a period of 168 curing hours by means of automatic intermittent sprinkling or a continuous wetting system. This may require approximately 1/8 inch to ¼ inch of the concrete to be removed. In all cases the surface laitance shall be removed to provide a solid profile on which to bond the overlay. The cost of shot -blasting of the concrete deck shall be considered incidental to the Specialized Concrete Overlay.
679.3.3 -Preparation of Surface: Blastcleaning shall be performed to thoroughly clean all horizontal and vertical receiving su rfaces. Surfaces, which will be in contact with the specialized concrete overlay, shall have laitance and partially loosened chips of concrete removed by blastcleaning, which shall produce a bright, clean appearance. The edge of previously placed pourss hall be similarly treated to promote bond. All reinforcing steel, or other steel, which is to be in contact with the new concrete, shall be cleaned of all grease, dirt, concrete mortar and injurious rust. Injurious rust is defined as all scale, loose rus t deposits, or all rust not firmly bonded to steel. Rust and concrete deposits, which in the Engineer's opinion cannot be removed by blastcleaning, will be considered firmly bonded and may remain. Any portion of a reinforcing bar judged by the Engineer t o have any more than 50% section loss shall be replaced at no additional cost to the Division. A light coating of orange colored rust that forms on the reinforcing steel after blast cleaning is not considered detrimental to bond and may remain unless the t ime limit that follows is exceeded, or if ordered to be removed by the Engineer. All debris from the blastcleaning operation shall be removed. After removal, the exposed reinforcing steel shall be supported and tied. Rustproof chairs shall be provided. If a continuous length of six ( 6) feet or more of reinforcing bar is exposed, the Engineer may require supports and positive tie -downs at a maximum spacing of four ( 4) feet. Positive tie - downs shall consist of anchors drilled into the structural slab and connected to the reinforcing bars. Replacement bars shall be spliced to existing bars using either minimum 30 bar diameter lap splices, approved mechanical connectors, or a welded splice as directed by the Engineer. Welded splices, if approved, shall be i n accordance with ANSI/AWS Structural Welding Code
734 - Reinforcing Steel D1.4. The Engineer shall be allowed sufficient time to inspect the work after the supporting and tying of the reinforcing steel has been completed. Blastcleaning operations may be com menced in an area after necessary concrete removal, per Section 679.3.1 or Section 679.3.2, as applicable, has been completed. If more than 48 hours elapse from the termination of any blastcleaning operation to slab wetting, blastcleaning shall be repeated per the Engineers direction regardless of the apparent condition of the receiving surfaces.
679.3.4 -Structural Slab Wetting: The structural slab surface and any other porous surface, which will be in contact with new concrete, shall be prewetted with water. All standing water in depressions or areas of concrete removal shall be blown out with oil -free compressed air. The surface shall be thoroughly wetted to a saturated surface dry condition and shall be visibly moist when placement begins.
679.3.5 -Placement Preconditions: Slab reconstruction concrete, or overlay concrete, shall be placed only after all of the following preconditions are satisfied: The Contractor has submitted to the Engineer, in writing, the proposed sequence of operations, equipment, number of personnel, and category of personnel to be used during the concrete placement.
concrete overlay placement. In no case shall this be less than one span long.
large enough to r equire one working day for concrete overlay placement. In no case shall this be less than one span long.
679.3.6 -Placing, Finishing and Curing Slab Reconstruction Concrete: Slab reconstruction concrete shall be placed separately from overlay concrete except when both of the following conditions are, in the opinion of the Engineer, present:
overlaid.
When these two conditions are present, slab reconstruction concrete may be placed integrally with overlay concrete. The Contractor has the following choices of concrete placed as slab reconstruction concrete: Overlay Type Slab Reconstruction Concrete Latex Modified Latex Modified or Class K Silica Fume Silica Fume or Class K
Slab reconstruction concrete placed integrally with overlay shall match the Specialized Concrete Overlay. The horizontal and vertical surfaces on which the slab reconstruction concrete is being placed shall be in a saturated surface dry condition immediately prior to placing any concrete. When Class K Concrete is used as reco nstruction concrete, a self -contained mobile mixer meeting the requirements of 679.2.3.4 may be used to provide the concrete.
735 After blastcleaning is completed, the Contractor shall place slab reconstruction concrete in the locations where reinforcing bar s have been exposed. The concrete shall be consolidated by internal vibration in accordance with Section 601.10.3 of the Specifications. It shall be finished to the level of the surrounding concrete, or to the middle of the reinforcing steel, whichever i s higher. The surface of the new concrete shall be intentionally roughened to a raked finish. Placement of slab reconstruction concrete in accordance with this subsection shall not relieve the Contractor of the requirements to provide the minimum required thickness of overlay material.
679.3.6.1 -Slab Reconstruction Concrete Curing Requirements: Curing shall be accomplished in the following manner: Latex Modified Concrete. Curing shall be performed in accordance with 679.3.7.5.1. Silica Fume and Class K Concrete. Curing shall be by means of quilted covers, or plastic -coated fiber blankets. Quilted covers, if used, shall be kept wet for the entire curing period in accordance with 679.3.7.5.2. The wet curing period shall be 72 curing hours. The use of membrane curing compounds shall not be allowed.
679.3.6.2 -Removal of Slab Reconstruction Concrete Surface: The slab reconstruction concrete surface shall be blastcleaned per the requirements of Section 679.3.3 prior to the placement of the overlay.
679.3.7 -Placing and Finishing Specialized Concrete Overlay: 679.3.7.1 -General: The following requirements shall apply for specialized concrete overlay placements:
Contractor shall restore the concrete overlay in a uniform manner to match existing grade unless otherwise directed by the Engineer. Under no circumstance, the ov erlay thickness shall not be less than 1 ¼ inches.
any source and shall be in a saturated surface dry condition immediately prior to concrete placement.
concrete shall be a minimum of 28 days old. The sidewalks, parapets, or curbs shall be a minimum of 7 days old.
679.3.7.2 -Finishing Equipment: Supporting rails upon which the finishing machine travels shall be placed outside the area to be overlaid. Said rails shall be supported at spacings sufficient to prevent any deflections. If deflections occur, support spacings shall be reduced, or rails sha ll be replaced by more resistant rail material. Anchorage of supporting rails shall provide for horizontal and vertical stability. The Engineer may require positive anchorage. A hold -down device shot into the prepared surface, or new overlay, will not b e permitted. Supporting rails shall not be treated with parting compounds or release agents to facilitate their removal. Immediately prior to the beginning of overlay operations, the finishing machine shall be operated over the full length of the bridge segment to be overlaid. This test run shall be made with the screed adjustment set to its finishing position. While operating the finishing machine during the test, the screed rails shall be checked for deflection and the minimum overlay
736 thickness confirmed. The clearance shall be checked with the use of 1¼ inches thick filler blocks attached to the bottom of the screed duri ng the test run. All necessary corrections shall be made prior to any concrete placement.
679.3.7.3 -Placement: The following requirements shall apply during placement of the Specialized Concrete Overlay: No concrete shall be placed unless surface slab temperature requirements of 679.4.6 and 679.4.7 are met. So that the use of hand tools will be kept to a minimum, concrete shall be deposited as nearly as possible to its final position. Internal vibrators shall not be used for moving concrete into position.
consolidate the concrete to prevent voids.
off, screeded, and finished to fi nal grade.
Variations in pavement surface in excess of 1/8 in ch above, or below, the proper finished elevation, or surface irregularities of more than 1/8 in ch in ten (10) feet, will not be accepted.
continued beyond the joint location a distance at least equal to the placement depth, and shall be allowed to stand free or shall be formed. Af ter the overlay has cured, the concrete shall be sawed to a depth of ¾ in ch ± 1/8 in ch. The overlay material beyond the saw cut shall be chipped out to the level of the original prepared surface, or to the level of the reinforcing bars, whichever is highe r. The chipped face of the construction joints shall not undercut the saw cut and shall have a slope of approximately 45°. Chipping hammers shall use only chisel bits.
operations exceeding 30 minutes duration. During any delays of 30 minutes or less, the placement shall be protected from drying with several layers of wet burlap. If the concrete placement is stopped, or delayed, for 90 minutes or more, further placemen t shall be discontinued and may be resumed only upon the approval of the Engineer. When a placement delay greater than 90 minutes occurs, the Contractor shall saw and seal a control joint in the overlay.
All placement operations shall stop when it starts to rain. The Engineer may order removal and replacement of material damaged by rainfall in accordance with 679.4.9.
operations will not be permitted.
679.3.7.4 -Surface Texturing: The surface of the specialized concrete overlay shall be uniformly smooth, dense and even. The surface shall then be given a suitable texture with an approved burlap drag. The Contractor shall texture in a transverse or longitudinal direction. Once begun, the direction of texturing shall not change. All texturing shall be performed prior to the beginning of curing operations. Only one pass of the drag o ver the finished area will be permitted. Texturing shall be in strict accordance with the time requirements of 679.3.7.5 for applying wet burlap.
737 If texturing is done in the transverse direction, the Contractor shall texture by hand methods as soon as practical after finishing machine passage. If texturing is done in the longitudinal direction, the burlap drag shall be a seamless strip and shall be attached to the work bridge such that the surface of the concrete is textured as soon as practical after finishing machine passage. Small areas, inaccessible to the attached drag, may be textured by hand methods. The finishing movement and resulting progress of the burlap drag shall be done in a manner so as to prevent ridges or gouges from forming in the concrete surface. The drag shall be weighted and the contact area changed as required to produce a texture acceptable to the Engineer. The drag shall be cleaned as required; to remove all hardened concrete particles. Texture resulting from the drag shall stop within one ( 1) foot of curbs or parapets.
679.3.7.5 -Curing: It is the nature of specialized concrete overlay material to quickly form a plastic film at the surface upon drying. This film is to be protected from drying and cracking by prompt cove ring with wet burlap. The temperature of the water for the wet burlap shall not exceed the maximum ambient temperature of the last 24 hours by more than 5°F. Regardless of the type of concrete placed, the use of membrane curing compounds will not be allo wed. Floor drains shall be immediately unplugged to permit the deck to drain. The overlay surface shall be completely covered with clean, wet burlap. The burlap shall be thoroughly saturated over its entire area, but shall be drained of excess water bef ore application. Burlap shall be lapped a minimum of one ( 1) foot and shall lay flat. Failure to apply wet burlap within 30 minutes after discharge of the concrete from the truck and within 10 minutes of the completion of finishing operations shall be cause for rejection of the work as determined by the Engineer. Care shall be exercised to ensure that the burlap is well dra ined. Burlap shall be continuously wet for a period by means of automatic intermittent sprinkling or a continuous wetting system
679.3.7.5 .1-Curing Latex Modified Concrete: A layer of 4 -mil thick white polyethylene film shall be placed over the burlap as soon as possible. The overlay shall then be wet cured for 48 curing hours. Care shall be exercised to ensure the burlap remains saturated for the 48 -hour cure period. Plastic coated fiber blankets may be substituted for the polyethylene film, but sh all not replace the initial wet burlap. The film (or fiber blankets) shall be anchored along all edges and internally to prevent the loss of moisture and from being displaced. After the wet cure, the polyethylene film and burlap shall be removed and the concrete shall be air -cured for 48 hours.
679.3.7.5.2 -Curing Silica Fume Concrete: Care shall be exercised to ensure that the burlap is well drained. Burlap shall be continuously wet for a period of 168 curing hours by means of automatic intermittent sp rinkling or a continuous wetting system.
679.4 -CONSTRUCTION LIMITATIONS AND REQUIREMENTS : 679.4.1 -Stockpiling Aggregates: All aggregates shall be stockpiled at the concrete mixing site or another location approved by the Engineer. No stockpiling shall be permitted on the bridge deck unless approved in writing by the Engineer. Stockpiles shall be completely covered and no additions to approved stockpiles are permitted. The free moisture content of each aggregate type, at the time of batching, shall not exceed 7% of the saturated -surface dry weight of the fine or coarse aggregate or 8% total for b oth aggregates. Fine and coarse aggregates, which are stored in piles or bins, shall be kept entirely separated.
738 679.4.2 -Storage and Handling of Cement: Suitable provisions shall be made to prevent the loss of cement during handling. Cement to be sto red shall be kept in suitable weatherproof enclosures, which will protect the cement from dampness. Cement, which has developed lumps in storage, shall not be used.
679.4.3 -Vehicular and Equipment Restrictions: The operation of vehicles and equipment on or over, the structural slab area where concrete removal operations have been started is subject to the following restrictions:
679.4.3.1 -Vehicle Weight Limits: Vehicular traffic is limited to necessary construction equipment. No vehicle or constr uction equipment weighing in excess of 7000 lb., shall be allowed to operate on, or over, any area of structural slab which exhibits unprotected, fully exposed reinforcing steel.
679.4.3.2 -Runways: Properly supported runways shall be provided where conc rete transporting devices operate over exposed reinforcing steel and expansion devices.
679.4.3.3 -Reinforcing Steel Protection: Exposed reinforcing steel shall be protected from concrete transporting devices so that no debonding, loosening, bending, or breaking occurs. Reinforcement that is damaged by any of the Contractor's operations shall be removed and replaced to the satisfaction of the Engineer and at no additional cost to the Division.
679.4.3.4 -Loading Limitations during Curing: No construction load shall be permitted on new concrete until the specified curing period(s) has been completed. No structural slab concrete removal work shall be performed on structural slab areas adjoining new concrete during the time the new concrete is curing and until the overlay concrete has attained a compressive strength of at least 4,000 psi as outlined below. No newly placed concrete shall be opened to traffic until the overlay concrete has attained a compressive strength of at least 4,000 psi. T his strength shall be determined by an average of three compressive strength specimens which have been cured in conditions as similar as possible to the concrete which they represent.
679.4.4 -Concrete Placement Limitations: The temperature of the plastic concrete, as discharged from the mobile mixer or delivery unit, shall be at least 50˚ F but not more than 85˚F. If conditions are such that, in the opinion of the Engineer, these temperature requirements may not be met, the provisions of either Section 601.9.1 or 601.9.2 of the Specifications will apply. If the evaporation rate exceeds 0.05 lb./sq. feet per hour (see Figure 1), the Contractor shall make provisions (i.e. wind breaks, fogging, etc.) to reduce the rate to 0.05 lb/sq. feet prior to placing concrete. These provisions shall be maintained during the placement of the concrete. If the evaporation rate obtained from Figure 1 is close enough to the maximum allowable value of 0.05 lb./ sq. feet per hour that there may a discrepancy in the exact numerical value, the equation listed below (EQ 679.4.4) shall be used to obtain a more accurate value. The Evaporation rate shall be checked every hour of placement and the results given to the Division.
739 Equation 679.4.4: 𝑬=(𝑻𝒄𝟐.𝟓−(𝑯𝑻𝒂𝟐.𝟓))∗(𝟏+𝟎.𝟒𝑾)(𝟏𝟎−𝟔) Where: E = evaporation rate (lb/ft2/h) Tc = concrete temperature ( F) Ta = air temperature ( F) H = relative humidity % / 100 W = wind velocity (mph)
679.4 .5-Concrete Pavement at Night: If placement of any concrete is to be made at night, a plan which provides adequate lighting for the work area shall be submitted at least 14 days before concrete is placed for the Engineer's approval.
679.4.6 -Hot Weather Provisions: The requirements of section 601.9.2 and ACI 305R, Hot Weather Concreting shall apply except as modified in this section. No concrete shall be placed when the ambient air temperature or deck surface temperature, after prewet, is above 85°F. Concrete may be placed at an ambient air temperature of 85° F, if the deck temperature, after prewet, is no higher than 85° F, and falling temperatures are predicted, and then only if the prediction indicates a temperature of under of 85° F for the placement period. The time limitations for the placement of wet burlap, as required by 679.3.7.5, shall also apply.
679.4.7 -Cold Weather Provisions: The requirements of section 601.9.1 shall apply except as modified in this section. No concrete shall be placed if the a mbient air temperature or deck surface temperature after prewet, is below 50°F, except as noted. Concrete may be placed at an ambient air temperature of 50°F if the deck surface temperature, after prewet, is no less than 50°F and rising air temperatures a re predicted, and then only if the prediction indicates a temperature of over 50° F for the eight hours immediately after placement. If air temperatures are such that the minimum temperature will not be met, the Contractor may place concrete if external he at is provided (refer to 679.4.8). If the curing temperature , as defined in section 679.1.2.4 , drops below 45° F during the curing period, then the surface shall be enclosed and external heat shall be provided in accordance with the provisions of 679.4.8 . The time required for tenting will not be counted as curing time. Once external heat provisions are required, they shall remain on the surface until curing is complete, regardless of the ambient air temperature. If curing temperature falls below 32 °F, at any time during the curing period, the concrete will be rejected. Continuous wetting shall be replaced by wetting at regular intervals if, in the opinion of the Engineer, expected air temperatures could result in freezing of run -off water.
740 679.4 .8-External Heat Provisions: The provisions of ACI 306, Cold Weather Concreting, and the following modifications shall apply:
supply external heat after the initial 48 curing hours.
from carbon dioxide gas.
regular intervals in a manner satisfactory to the Engineer for silica fume concrete.
741 679.4.9 -Defective or Damaged Concrete: After the overlay has been cured, the Contractor in the presence of the Engineer shall sound the deck in order to detect delaminated areas. All defective or damaged concrete, as determined by the Engineer, shall be repaired or replaced at no additional cost to the Division. Defects shall include but not be limited to delaminations, cracking, tearing, damage or other imperfections. The Contractor shall propose repair methods for approval by the Engineer. All concrete requiring removal and replacement, a s determined by the Engineer, shall be removed by sawcutting the perimeter to a depth of ¾ inch ± 1/8 in ch. Damaged concrete shall then be chipped out to the level of the original prepared surface. The chipped face shall not undercut the sawcut and shall have a slope of approximately 45°. Chipping hammers shall use only chisel bits. The prepared surface shall be blastcleaned prior to reapplying the overlay concrete.
679.5 -FINAL BRIDGE DECK FINISH : 679.5.1 -Straightedge Test: After defective or damaged concrete has been repaired and cured in accordance with 679.4.9 and before opening to traffic, the bridge deck shall be grooved as set forth in 679.5.2. Prior to grooving, the entire deck shall be checked with an approved ten ( 10) foot rolling straightedge or approved inertial profiler and inertial profile operator as outlined in section 720.2.
679.5.2 -Finished Deck Grooving: 679.5.2.1 -Transverse Grooving: After corrective grinding and before opening to traffic, grooves sh all be cut into the concrete using a mechanical saw. These grooves shall be 0.10 inch wide and 0.25 inch deep. Groove spacing shall be 1.5 inches center to center. No later than one week prior to grooving operations, the Contractor shall provide the Engin eer with two accurate, easily readable gauges with which to verify groove dimensions. Groove depth and spacing tolerances are limited to ±1/16 inch. Groove width tolerances are +0.02 inch and -0.0 inch. Grooves shall be cut continuously across the deck to within one ( 1) foot of gutter lines or drainage structures. Grooves shall also be continuous across the full width of the deck surface including construction joints. Grooves shall terminate within one ( 1) inch of any exposed metal component or elastomeri c concrete of an expansion joint. When the deck is skewed and the contractor is using gang blades to saw the grooves, the maximum distance (measured perpendicular to the centerline of the expansion joint) from the last groove termination in the pass to the expansion joint shall be one ( 1) foot, eight (8) inches. Radial grooving shall be performed in increments limited to twelve ( 12) feet of bridge length.
679.5.2.2 -Longitudinal Grooving: Use diamond blades mounted on a multi -blade arbor on self-propelled machines that were built for grooving of concrete surfaces. The groove machines shall have depth control devices that detect variations in the pavement surface and adjust the cutting head height to maintain the specified depth of the groove. The grooving machines shall have devices to control alignment. Do not use flailing or impact type grooving equipment. More than one size grooving machine may be required in order to saw the grooves as specified. Provide an experienced technician to super vise the location, alignment, layout, dimension, and grooving of the surface. Saw grooves parallel to the bridge centerline in a continuous pattern across the surface. Begin and end sawing nine ( 9) to twelve ( 12) inches from any device in place in a brid ge
742 deck, such as scuppers or expansion joints. Stop sawing a minimum of two ( 2) inches to a maximum of twenty -four ( 24) inches from skewed expansion joints. Maintain a clearance of a minimum of two ( 2) inches and a maximum of four ( 4) inches from the grooves to longitudinal joints in the deck. Maintain a minimum clearance of nine ( 9) inches to a maximum of thirty ( 30) inches clearance between the grooves and the curb or parapet toe. However, at no point shall un -grooved portions of deck extend beyond edge l ine and into the temporary or permanent travelled lanes. Saw grooves in a uniform pattern spaced at ¾ inch minus ¼ inch or plus zero ( 0) inches. Saw grooves 0.15 inches deep and 0.10 inches wide. Groove tolerances for depth are +0.0625 inches and minus zero (0) inches. Groove tolerances for width are +0.02 inches and minus zero ( 0) inches. For staged, or phased bridge deck work, saw the grooves parallel to the final, permanent bridge centerline. If the different stages or phases of the bridge deck work occur within one construction season, any stage opened to traffic shall receive an interim coarse broom finish during placement, then saw the longitudinal grooves after the final stage. The interim broom finish will not be allowed as a surface texture when opened to traffic over a winter season. Saw longitudinal grooves in the deck prior to ope ning to traffic for a winter season. For bridge decks that widen from one end to the other, saw the longitudinal grooves parallel to the centerline of the roadway. On the side of the bridge that widens, saw the longitudinal grooves to follow the edge line. Saw longitudinal grooves in the gore areas, avoiding the overlapping of grooves. At the beginning of each work shift, furnish a full complement of grooving blades with each saw that are capable of cutting grooves of the specified width, depth, and spacing. If during the work, a single gr ooving blade on a machine becomes incapable of cutting a groove, continue work for the remainder of the work shift. The Contractor is not required to cut the groove omitted because of the failed blade. Should two or more grooving blades on a machine become incapable of cutting grooves, cease operating the machine until it is repaired. Continuously remove all slurry and remaining residue from the grooving operation and leave the deck surface in a clean condition. Prevent residue from grooving operations fro m flowing across shoulders or across lanes occupied by public traffic or from flowing into gutters or other drainage facilities. Remove solid residue before the residue is blown by passing traffic or by wind. Provide water as necessary to saw grooves acc ording to this subsection.
679.6 -METHOD OF MEASUREMENT : 679.6.1 -General: The quantity of work performed for Concrete Deck Overlay shall be measured in square yards. This quantity includes the removal of the existing deck surface and delivery of newly installed deck surface.
679.6.2 -Removal of Existing Surface: 679.6.2.1 -The removal of the existing deck surface as described in section 679.3.1.1 shall be one half ( ½ ) the field measured deck area to be removed and paid at the unit bid price for Item 679001 Concrete Deck Overlay.
679.6.2.2 -The removal of the existing deck surface as described in section 679.3.1.2 shall be the actual field measured areas in squar e yards of the locations and paid at the unit bid price for Item 679001 Concrete Deck Overlay.
743 679.6.2.3 -Full Depth Removal: It is reasonably expected that full depth removal of material will be encountered on the project at various locations. The Contractor will be required to fully repair such locations accounting for up to and including two percent (2%) of the deck area for the individual bridge deck being overlaid at no additional cost to the Division. As determined by the Engineer, when ful l depth repairs exceed 2% of the each bridge deck area being overlaid, the Contractor shall be paid $200 per square yard (SY) for each square yard (or fraction thereof) in excess of the 2% described above. For clarity, the phrase “each bridge deck being o verlaid” is not a cumulative Project total bridge area, but instead refers to a single bridge’s total deck surface area. It is likely a project will contain multiple bridges to be overlaid. Expansion dam area locations shall not be included in the bridge deck surface area measured.
679.6.3 -Newly Installed Deck Surface: The concrete and other materials used in the installation of the new deck surface once accepted by the Division shall be paid as one half (½) the field measured deck area as measured in section 679.6.2.1 and paid at the unit bid price for Item 679001 Concrete Deck Overlay
679.6.3.1 -Blast Cleaning : During New Construction projects only where no removal of existing surface is required, Blastcleaning of the deck surface as described in s ection 679.3.3, shall be paid at the unit bid price for 679001 Concrete Deck Overlay. Measurement shall be in square yard at one half (½) the actual field measured area to be Blastcleaned.
679.6.4 -Test Slab: will be measured on a lump sum basis comple te in place. This shall include the complete execution of work required herein, regardless of the number of test slabs constructed. This item may be deleted at the discretion of the Engineer.
679.6.5 -Slab Reconstruction Concrete: The quantity of work performed for Slab Reconstruction Concrete shall be incidental to Item 679001 Concrete Deck Overlay. Slab Reconstruction Concrete placed monolithic with the overlay shall be included in the overlay quantity.
679.7 -BASIS OF PAYMENT : The quantities, determined as provided above, will be paid for at the contract unit price bid for the items listed below. The price and payment shall be full compensation for all material removal and for furnishing and placing all the materials and doing all the work herein prescribed in an acceptable manner including all materials, labor, tools, equipment, supplies and incidentals necessary to complete the work.
679.7.1 -Rideability Price Adjustments: Section 601.15.2 of the Specifications shall apply to the finish requirements of the specialized concrete overlay.
744 679.8 -PAY ITEMS : ITEM DESCRIPTION UNIT 679001 -* Concrete Deck Overlay Square Yard 679006 -* Test Slab Lump Sum
* Sequence number
745 SECTION 681 ASBESTOS ABATEMENT
681.1 -GENERAL : 681.1.1 -Description of Work: The work to be performed under this section of the specifications comprises the furnishing of all labor, materials and equipment for completion of all work as shown elsewhere within this Special Provision and/or the Contract Plans. This work includes handling and removal of asbestos containing materials, and the incidental procedures, materials and equipment required to protect workers and/or occupants of the structure and adjacent areas from contact with airborne asbestos containing materials. All asbestos materials shall be disposed of in a landfill approved by the West Virginia Department of Environmental Protection, Division of Water and Waste Management, Solid Waste. This work is to be performed by a Certified/West Virginian Licensed Asbestos Abatement Contractor.
681.1.2 -Definitions: Except as specifically defined otherwise, the following definitions apply generally to the work of this section.
Abatement: Procedures to control fiber release f rom asbestos containing materials, including removal of asbestos containing material (ACM) as per this specification.
Air Monitoring: The process of measuring the fiber content of a specific volume of air in a stated period.
Amended Water : Water to whi ch a surfactant has been added.
Asbestos : Fibrous silicates with a crystalline structure, including chrysotile, amosite, crocidolite, tremolite, anthophyllite and actinolite.
Asbestos Abatement Contractor : Certified/WV Licensed Asbestos Contractor.
Asbestos Fibers : Asbestos fibers having an aspect ratio of 3:1 and longer than five (5) micrometers.
Authorized Visitor : WVDOH personnel, Authorized Agent of the WVDOH or a representative of any regulatory agency having jurisdiction over the project.
Class I Project : A Class I project as defined in OSHA as being abatement of asbestos containing insulating, surfacing and/or thermal surfacing materials.
Class II Project : A Class II project as defined in OSHA as being th e abatement of any asbestos containing material other than insulating, surfacing and/or thermal surfacing materials.
Clean Room : An uncontaminated area or room, which is part of the worker decontamination enclosure system, with provision for storage of w orkers street clothes and protective equipment.