614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI)
600-86 (6) Adjustment of Manholes (Set Price). When required, this work will be performed and paid for under
SECTION 816 .
7.Construction Joints.
a.Transverse Construction Joints. Use a met hod of making transverse construction joints to provide a thorough and c ontinuous bond, provide an acceptable surface texture and meet density requirements. Do not vary the surface elevation more than 3/16 inch in 10 feet, when tested longitudinally across the joint. When required, repair the joints or paving operations will be suspended.
b.Longitudinal Joints. Construct well bonded a nd sealed longitudinal joints to obtain maximum compaction at the joint. If deemed necessary by the Engineer to properly seal the joint, apply a light coat of asphalt emulsion or asphalt binder to the exposed edge before the joint is made. Before placing the fresh HMA against a cut joint or against old pavement, spray or paint the contact surface with a thin uniform coat of asphalt emulsion or asphalt binder. Where a finishing machine is used, make the longitudinal joint by depositing a sufficient amount of HMA to form a smooth and tight joint. Offset the longitudinal joint in successive courses by 6 to 12 inches. Comply with traffic lane edges for the width of the surf ace of top course placement.
f.Maintenance of Traffic . Maintain traffic according to DIVISION 800 and the following: Maintain one-way traffic, and restrict traffic speeds to 20 miles per hour in the vicinity of workers, unless otherwise designated. Use pilot cars to lead traffic through the area of pavi ng and rolling operations , and if directed, through a curing area. The use of flaggers is allowed th rough patching operations, unless the patching area or distance between flaggers exceeds ½ mile, in which case the use of a pilot car shall be required. On overlay projects with 2 lanes or more in each direction for traffic use, the Engineer may waive th e pilot car requirements. Station one flagger ahead of the application of the tack coat and one flagger ahead of the area being protected from traffic. Take adequate protection for tr affic on side roads approaching the tack area.
g.Treatment of Adjacent Areas. Pave sideroads, entrances and turnouts for mailboxes as shown in the Contract Documents. Overlay all widening areas designated in the Contract Documents or ordered by the Engineer.
h.Special RCI Requirements. Technical Support: Personnel familiar with the process will provide technical support for production and placement of the RCI. Tack Coat: Place a tack coat pr ior to the placement of the RCI. Thickness: Compact the RCI, as a minimum, to the depth shown in the Contract Documents. Thicknesses less than the plan thickness are not acceptable and may resu lt in removal and replacement at no additional cost to KDOT. Longitudinal Joint: Overlap the PCCP or HMA longitudinal joint with the RCI by at least 6 inches. Compaction and Density: Control the in-place density of all lots of the RCI using an approved rolling procedure as outlined in subsection 614.4e . If cores are taken use extreme care when handling the cores. Use a solid flat and un-textured surface to transp ort and store the cores prior to testing. Release to Traffic and Overlay Placement: Cover the RCI with a hot mixture over lay within 10 days after placement. The RCI may be opened to traffic or covered w ith the hot mix overlay after cooling to less than 140°F or as determined by the Engineer. Unacceptable work: Remove and replace areas dete rmined unacceptable by the Engineer, in accordance with this specification, at no additional cost to KDOT. Damaged Areas: Replace any traffic-damaged or marred areas at no additional cost to KDOT. Blisters: Perforate blisters that are a minimum of 8” in diameter or a minimum of 1” high that have not disappeared by the time of the overlay using a method approved by the Engineer.
i.Pavement Smoothness. Evaluate pavement smoothness according to SECTION 603 . 614.5 PROCESS CONTROL
a.General. Establish gradation limits and proportions for each individual aggregate and mineral filler. Specify the limits and proportions such that the material produced complies with the applicable requirements of the 614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI)
600-87 designated mix type. The Contractor is responsible for all process control operations including testing. At no time
will KDOT’s representative issue instructions to the Contractor or producer as to setting of dials, gauges, scales and meters. KDOT will collect and test verification samples an d assurance samples and inspect the Contractor’s quality control operations.
b.JMF Adjustments. Produce a mixture of uniform composition closely complying with approved design JMF to obtain the specified properties when compacted. If, during production, results from quality control tests demonstrate a need to make adjustments to the mix design, then make adjustments to the design JMF single point gradation and binder content to achiev e the specified properties. The JMF adjustments shall produce a mix that complies with TABLE 614-1 for the specified mix designation. When necessary, adjust on a sublot basis. Report the new JMF to KDOT’s field representative and the DME before making such changes, and submit a new mix design for review and approval if required by the DME.
c.Specification Working Ranges. Establish acceptable limits for fiel d test results by applying the tolerances shown in TABLE 614-7 to the JMF or adjusted JMF for bind er content and air voids. Establish acceptable limits for the other listed mix charact eristics by applying the tolerances shown in TABLE 614-7 to the requirements of TABLE 614-1 . TABLE 614-7: SPECIFICATION WORKING RANGES (QC/QA) Mix Characteristics Tolerance from JMF Single Test Value Plot 4 Point Moving Average Value Plot Binder Content ±0.5% * ±0.3% * Air Voids @ N des gyrations ±1.0% * ±1.0% * Mix Characteristics Toleranc e for Specification Limits Single Test Value Plot 4 Point Moving Average Value Plot Gradation (applicable sieves shown in TABLE
614-1 ) ** * zero tolerance *
Voids in Mineral Aggregate 1.0% below min. * zero tolerance * Voids Filled with Asphalt zero tolerance n/a Sand Equivalent zero tolerance n/a *Values to plot. For gradations, as a minimum, plot the No. 8, No. 16, No. 50, and No. 200 sieves. ** The maximum deviation from the JMF shall be ±4 % for No. 16 sieve and ±1 .0% for No. 200 sieve. 614.6 WEATHER LIMITATIONS Do not place HMA on any wet or froz en surface or when weather conditi ons otherwise prevent the proper handling and finishing of the mixture. Only place HMA when either the mi nimum ambient air temperature or the road surface temperature shown in TABLE 614-8 is met. TABLE 614-8: MINIMUM RCI PLACEMENT TEMPERATURES Paving Course Thickness (inches) Air Temperature (ºF) Road Surface Temperature (ºF) RCI All 50 55 614.7 MIXTURE ACCEPTANCE
a.General. Test the RCI at each pl ant for compliance with TABLE 614-1 . Acceptance will be made on a lot by lot basis contingent upon satisfactory test results. Obtain quality control and verification samples of the RCI using KT-25 sampling procedure D.2 Truc k Bed. The sampling device and procedures used to obtain and split the samples must be approved by the Engineer. The Contract or’s quality control tests will be used for acceptance provided those results are verified by KDOT. 614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI)
600-88 A load or loads of mixture which, in the opinion of the Engineer, are una cceptable for reasons such as being
segregated, aggregate being improperly coated, foaming aggr egate or being outside the mixing temperature range may be rejected. The Engineer will take verification sample s using the same sampling and splitting procedure as approved for the Contractor’s quality control tests. The P b test values will also be used to determine P b pay adjustments according to subsection 614.8b . P b pay adjustments apply to the RCI placed on the traveled way and shoulders (including ramps and acceleration and deceleration lanes).
b.Lot Definition for Mix Production Sampling and Testing. A lot is defined as an isolated quantity of a specified material produced from a single source or operation. Each lot shall normally be represented by 4 contiguous test results. A lot may be represented by test results on samples taken from 1 or more day’s production.
c.Lot Investigation. The Engineer may examine materials represented by individual test results which lie beyond the Contractor’s normal quality control testing variation. The investigation may be based on either Contractor or KDOT test results. The information from additional testing (including testi ng of in-place RCI) may be used to define unacceptable work according to subsection 105.5 . The Engineer may apply appropriate price reductions or initiate corrective action. For any test, if a dispute exists between the Engineer and Contractor about the validity of the other’s test results, the KDOT District Material s Laboratory or the MRC will perfo rm referee testing, except for P b dispute resolution. If the disputed KDOT test results were genera ted at the District Laboratory, the MRC will perform the referee tests. If the disputed KDOT te st result was generated at the MRC, an independent laborator y agreeable to both parties will be selected. The Laborator y shall be accredited by the AASHTO Accr editation Program in the appropriate testing category. If referee testing indicates that KDOT test results are co rrect, the Contractor pays for the additional testing, including referee testing performed at the MRC. This will be paid using the bid item Contract Deduct which will be an item added to the contract. If the referee testing indicates that C ontractor test results are correct, KDOT pays for the additional testing. Pay the independent lab for the testing and submit the pa id invoice to KDOT. The Engineer will reimburse the Contractor (based on the invoice price) as Extra Work, SECTION 104. For P b dispute resolution (the statistical comparison fails and the Contractor questions KDOT results), the following procedure applies for the lots in question: Determine which lots to dispute. Only dispute the lot produced immediately prior to the lot currently under production and being tested. Notify the Engineer, prior to the completion of all Contractor P b testing for this lot. (When production is completed for any mix, the last lot may be challenged the day production is completed). Discard P b and P b pay adjustment factors previously determ ined within the lots being questioned. All back halves of samples within the lot in question will be taken by KDOT to the District Materials Laboratory. All back halves of samples shall be a minimum of 35 pounds. Failing to obtain enough material removes the right to dispute resolution. Copies of all paperwork, including work sheets, associated with previous P b calculations for the disputed lots will also be taken to the District Materials Laboratory. The following retesting will be completed by KDOT: Determine the P b using the back half of all samples within the lot being questioned using KT-57. Normally, there will be 5 back halves (4 Contr actor’s and 1 KD OT) to test within each lot. Using the retest P b results, a statistical comparison will be ma de. If the t-test passes, the Contractor’s retest results will be used to calculate the pay factor and KDOT will pay for all retesting. Use the procedures shown in subsection 614.8b. If the t-test fails, KDOT’s retest results will be used to calculate the pay factor, and the Cont ractor will pay for all retesting. When a deficiency within a lot is determined to exist for properties other than P b (P b deficiencies are addressed elsewhere in the specification) , the Engineer will decide on the dispos ition of each lot as to the acceptance, rejection or acceptance at an adjusted paym ent. The Engineer’s decision is final.
d.Resampling of Lots. Take no samples for retest for pay adjustment purposes except as noted in subsection 614.7c . 614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI) 600-89
e.Multiple Projects. If multiple projects are supplied from 1 or more plants using the same mix, carry over the lots at each hot mix pl ant from project to project.
f.Lot Size. A standard size mix production lot consists of 4 equal sublots of 750 tons of RCI (lot size is 3,000 tons). It is anticipated that lot size shall be as specified. However, with the Engineer’s approval, the Contractor may re-define lot size for reasons such as, but not limited to, change in contract quantities or interruption of the work. Take 1 sample during production of each sublot and utilize it to determine di sposition of the lot in which it occurs.
g.Increased Lot Size. After 8 consecutive sublots have been produced within the tolerances shown for all mix characteristics listed in TABLE 614-7 and without a P b penalty, the sublot size may be increased to 1,000 tons (lot size of 4,000 tons), provided the normal production rate of the plant is greater than 250 tons per hour. Provide immediate notification of lot size changes to the Engineer any time a change is made. If subsequent test results fall outside the tolerances shown for any mix characteristic listed in TABLE 614- 7 or a P b penalty is incurred, the sublot size shall be decrease d to 750 tons. When the increased lot size criteria are again met, the sublot size may be in creased to the limits given above.
h.Decreased Lot Size for Small Quantities. This is to be used when a small quantity (less than 3,000 tons) of RCI will be used. Use the plan quantity for the lot size. Reduce the sublot size below 750 tons by dividing the lot into 3 or 4 equal sublots. Before beginning production, provide the Engineer with the number and size of the sublots.
i.Pre-Production Mix. Test and evaluate a pre-production mix, limited to a maximum of 200 tons from each plant and type of mix before produc tion of that mix. Evaluate the pre- production mix at in itial start-up and after suspension of production resulting from failing test results. P b payment shall not be adjusted for pre- production mixes. Provide a pre-production mix that complies with the gradation, P b, VMA, and laboratory V a requirements prior to starting or resuming production. For P b, Va, and VMA, use the "Single Test Value" listed in TABLE 614-7 for comparison. For the other tests listed, use the values listed in TABLE 614-1 for each mix. Except for initial start-up, normal delivery of material to the project before completion of certain test results on pre- production mixes may be authorized by the DME. Place the material produced for the pre-production mix in locations approved by th e DME. The Engineer will pay for material as the material produced. At the direction of the Engineer, remove the pre-production mix if it is both out of specification and the material shortens the pavement life or changes the intended function. The Engineer will pay for the replacement of one pre-production mix at 100% of the contract unit price for the RCI. The payment will be full compensa tion to the Contractor for the placement a nd removal of that pr e-production mix. KDOT will not be financially responsible for any subseque nt failed pre-production mixes (that require removal) for the RCI. The removed material is the property of the Contractor. The Engineer will not pay for pr e-production mixes that are requir ed to be replaced due to poor workmanship or equipment failure. The Engineer will make the final decision to remove a failed pre-production mix with input from the Contractor.
j.Suspension of Mix Production. Suspend production of the mix until appropriate corrections have been made, if 2 consecutive test results for any single mix characte ristic fail to fall within the limits established by the tolerances shown in the single test value column of TABLE 614-7 . Additionally, suspend production of the mix until appropriate corrections have been made, if any 4-po int moving average value for any single mix characteristic fails to fall within the limits established by the toleran ces shown in the 4-point moving average value column of TABLE 614-7 . Production remains suspended pending the satisfactory results of a pre-production mix, unless waived by the DME. The Engineer may stop production of RCI at any time the mix or process is determined to be unsatisfactory. Make the necessary corrections before pr oduction will be allowed to resume. Failure to stop production of RCI shall subject all subsequent material to rej ection by the Engineer or acceptance at a reduced price, as determined by the Engineer. 614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI)
600-90 614.8 Basis of Acceptance
a.General. Acceptance of the mixture will be contingent u pon test results from both the Contractor and KDOT. The Engineer will routinely compare the variances (F -test) and the means (t-test) of the verification test results with the quality control test results for P b using a spreadsheet provided by KDOT. If KDOT verification test results do not show favorable comparison with the Contract or’s quality control test results, then KDOT test results will be used for material acceptance, material rejection and the determination of any pay adjustment on the P b. Disputed test results will be handled according to subsection 614.7c . KDOT will use a spreadsheet program to calculate pay adjustments for P b, and to compare Contractor QC and KDOT QA test results. KDOT will provide a copy of this program to the Contractor, when requested. Microsoft Excel software is required to run this program; it is the Contractor’s responsibility to obtain the correct software. Values computed using equations referenced in this specification may vary slightly from the spreadsheet values due to rounding of numbers. In such cases, the numbers computed by the spreadsheet will govern. The comparison of quality control and verification test s will be completed using the t-tests to compare their population means and the F-test to comp are their variances. The F & t tests, along with the Excel Spreadsheet used to compare the Contractor’s QC results and KDOT’s QA results, are described in Section 5.2.6, Part V. Additional information on the program may be obtained from the Bureau of Construction and Materials.
b.Asphalt Binder Pay Adjustment. Asphalt Binder (P
b.Pay Adjustment will be made on a lot basis and based on measured P b from samples of plant produced material. The P b pay adjustment factor ( PB) (positive or negative) will be determined and used to compute the P b pay adjustment by multiplying PB times the number of tons included in the lot times $40 per ton. This adjustment will be paid for under the bid item Asphalt Binder Pay Adjustment. When the statistical comparison between the quality control and the verification tests pass, use the procedures in subsection 614.8b.(1) to compute P
B.When the statistical comparison fails, calculate PB using procedures in subsection 614.8b.(2) . Asphalt Binder Lot Size: A lot shall normally be comprised of the results of 4 contiguous individual P b tests as determined from the ignition oven burn-off procedure (KT-57).
1.Asphalt Binder Pay Adjustment Factor (Passing t-test). Calculate the upper and lower P b quality indices (QUB and QLB) for each lot using Equations 3 and 4, respectively and round to hundredths. Locate the QUB value in the left column of the Percent Within Limits (PWL) Table in Section 5.2.1, Part V. Select the appropriate upper percent within limit value ( PWL UB) by moving across the selected quality index row to the column representing the number of samples (N) in the lot. Repeat the process using the QLB value and select the ap propriate value for the lower percent within limits ( PWL LB). If the QUB or QLB value is greater than the largest quality index value shown in the table, then a value of 100.00 is assigned as the value for PWL UB or PWL LB, respectively. If both QUB and QLB exceed the values shown in the table, a value of 100.00 is assigned as the value for both PWL UB and PWL LB. If either QUB or QLB is a negative value or PWL UB + PWL LB is less than 150.00, the Engineer will determine if the material in the lot may remain in place. If the Engineer determines that th e material may remain in place then the maximum value of PB for the lot will be equal to –0.060. The Engineer may establish lower values for PB (-0.100, -0.200, etc.) in such instances. Otherwise, calculate PB using Equation 3 and round to thousandths. Equation 1: SX USL QUB Equation 2: SLSL X QLB X is the average measured P b of all samples within a lot rounded to hundredths. USL is the upper specification limit for P b, and is defined as 0.30% higher than the JMF P b. LSL is the lower specification limit for P b, and is defined as 0.30% lower than the JMF P b. S is the standard deviation of the measured P b for all samples within a lot and is calculated using equation
4.in Section 5.2.1, Part V, rounded to hundredths. Equation 3: PB = ((PWL UB + PWL LB - 100)(0.0015)) – 0.135 PWL UB is the upper percent within limits value for P b. PWL LB is the lower percent within limits value for P b. 614 – HMA BASE (REFLECTIVE CRACK INTERLAYER (RCI) 600-91
2.Asphalt Binder Pay Adjustment (Failing t-Test). If the t-test fails, KDOT’s test result will be used to calculate the PB for the lot. Follow the procedures given in subsection 614.8b.(1) to determine the PB or disposition of the lot. Use the values from TABLE 614-9 to calculate QUB, QLB, PWL UB and PWL LB in Equations 1, 2 and 3 in subsection 614.8b.(1) . TABLE 614-9: Statistical Values for Asphalt Binder Pay Adjustment for Failing t-Test Term Definition Value X Average or Mean KDOT’s test result for the lot S Standard Deviation 0.20 USL Upper Specification Limit 0.50% + JMF P b LSL Lower Specification Limit JMF P b - 0.50% N Sample Size 3 614.9 MEASUREMENT AND PAYMENT
a.HMA-RCI (PG 70-28 RCI). The Engineer will measure HMA -RCI by the ton of material at the time of delivery to the road. Batch weights will not be allowed as a method of measurement unless all the following conditions are met: the plant is equipped with an automatic printer system approved by the Engineer; the automatic printer system prints the weights of material delivered; and the automatic printer system is used in conjunction with an automatic batching and mixing control system approved by the Engineer. Provide a weigh ticket for each load. Due to possible va riations in the specific gravity or weight per cubic foot of the aggregates, the tonnage used may vary from the proposal quantities and no adjustment in contract unit price will be made because of such variances. Payment for "HMA -RCI" at the contract unit prices is full compensation for the specified work. Any pay adjustments will both be applied and the payment adjusted accordingly.
b.Emulsified Asphalt. The Engineer will measure emulsified asphalt used for tack by the ton. Payment for "Emulsified Asphalt" at the contract unit price is full compensation for the specified work.
c.Quality Control Testing (HMA). The Engineer will measure Quality Control Testing (HMA) performed by the Contractor on a per t on basis of HMA-RCI placed on the project . No adjustment in the bid price will be made for overruns or underruns in the contract quantity. The bid price will constitute payment for all necessary mix design testing, field process control testing, the testing laboratory and all necessary test equipment. Payment for "Quality Control Testing (HMA)" at the contract unit price is full compensation for the specified work. 615 – SAW AND SEAL JOINTS (HMA OVERLAY)
600-92 Section 615
SAW AND SEAL JOINTS (HMA OVERLAY) 615.1 DESCRIPTION Provide materials for, locate, saw, clean, and seal jo ints in the HMA overlay at the locations shown in the Contract Documents or as designated by the Engineer. BID ITEMS UNITS Saw and Seal Joint (HMA) Linear Foot Asphalt Core (Set Price) Each 615.2 MATERIALS Provide hot type joint sealing compound complying with DIVISION 1500 . 615.3 CONSTRUCTION REQUIREMENTS
a.General. Begin the saw and seal operation a minimum of 48 hours after placing the surface course to allow the mat to cool. Complete the saw and seal ope ration prior to the end of the construction season (as established for asphalt paving) or proj ect completion, whichever is earlier. Coordinate the sawing, cleaning and sealing in a continuous operation.
b.Sawing the Joint. Reference the location of the existing joints in the concrete pavement before placing the HMA overlay by methods approved by the Engineer. Use a saw that will produce a smooth cut for the required depth and width. Configure the joints according to FIGURE 1 within 1 inch horizontally above the existing joint. Saw the entire depth and width in one single pass for the entire length of the cut. Saw transverse joints the entire width of the HMA Overlay. Use either a dry or wet saw method.
c.Clean the entire depth of the cracks. If the wet saw method is used, flush wet sawed joints with high pressure water until the water runs clear. For either saw method, remove all material created by sawing operation and other foreign material that will prevent bonding of the sealant. Remove loose material on the surface immediately adjacent to the joints and cracks. Clean and dry the crack using air compressors equipped with suitable traps capable of removing all surplus water and oil from the compressed air.
d.Joint Depth and Location Verification. Before sealing the joints, the Engineer will randomly identify two transverse joints per lane-mile. Cut a 4-inch core through the entire depth of the HMA and PCCP at these locations. The Engineer will measure the depth of the HMA overlay , the depth of the saw cut and the horizontal offset between the underlying PCCP joint and the sawed joint. If the sawed joint is offset by more than the 1 inch tolerance, the Contractor will be assessed a Contract Deduct of 40% of the bid price fo r the lineal feet of joints represented by the deficient core.
1.HMA Overlay > 1.0 inch. If the depth of the saw cut is less than the half of the HMA thickness, ± 1/8 inch, re-saw every joint to the required depth in the se gment represented by the core. Take additional cores for verification of re-sawed joints, at randomly selected locations determined by the Engineer. Dry the core holes, tack the sides and bottom, fill with the same type of material and properly compact. 615 – SAW AND SEAL JOINTS (HMA OVERLAY)
600-93 Figure 615-1: Full-Width Sa W Cut, Hma Overlay > 1.0 Inch
2.HMA Overlay ≤ 1.0 inch. If the depth of the saw cut is less than the full HMA overlay thickness, re- saw every joint to the required depth in the segment repres ented by the core. Take additional cores for verification of re-sawed joints, at randomly selected locations determined by the Engineer. Dry the core holes, tack the sides and bottom, fill w ith the same type of material and properly compact. FIGURE 615-2: ENTIRE-DEPTH, FU LL-WIDTH SAW CUT, HMA OVERLAY ≤ 1.0 INCH 615 – SAW AND SEAL JOINTS (HMA OVERLAY)
600-94 e. Preparation of Asphalt for Joint Sealing. Provide 2 copies of the ma nufacturer’s recommendations for
preparation and application of the sealant. Prepare and use the material according to the manufacturer’s recommendations.
f.Sealing the Joint. Apply the joint sealant by an approved mechanical devi ce. Place the sealer the entire depth in close conformity with dimensi ons shown in the Contract Documents. F ill joints to a level 1/4-inch recessed from the pavement surface. Do not permit traffic over sealed joints until the sealer is tack free, or until debris from traffic can not imbed into the sealant and sealant does not track under tires.
g.Weather Limitations. Do not place sealant when the ambient air temperature is below 40 F. 615.4 MEASUREMENT AND PAYMENT The Engineer will measure sawing and sealing joints by the linear foot along the center of the joint. The Engineer will measure each asph alt core required to verify the saw depth and location. Payment for "Saw and Seal Joint (HMA)" and "Asphalt Core (Set Price)" at the contract unit price will be full compensation for the specified work. The Engineer will apply a Contract Deduct of 40% of th e bid price for lineal feet of deficient joint offsets as determined in subsection 615.3d. above. The bid item Contract Deduct will be an item added to the contract. 701 - TEMPORARY SHORING
700-1 Section 701
TEMPORARY SHORING 701.1 DESCRIPTION Design and construct temporary shoring for the locations designated in the Contract Documents and any temporary shoring used for the Contractor’s convenience. B I D I T E M U N I T S T e m p o r a r y S h o r i n g L u m p S u m 701.2 MATERIALS Provide the materials shown in the Temporary Shoring Plan. The Engineer will accept the temporary shoring materials based on compliance with the dimensional requirements and visual inspection for condition. 701.3 CONSTRUCTION REQUIREMENTS For each location designated in the Contract Documents, submit the Temporary Shoring Plan (including the design calculations) sealed by a license d Professional Engineer, according to SECTION 105 , to the Engineer for approval a minimum of 6 weeks before the scheduled beginning of temporary shoring operations, unless shown otherwise in the Contract Documents. Shore, sheet, brace or otherwise sup port the excavation or th e structure according to the Temporary Shoring Plan. Maintain the temporary shoring un til the Engineer authorizes its removal. 701.4 MEASUREMENT AND PAYMENT The Engineer will measure each loca tion of temporary shoring designated in the Contract Documents by the lump sum. Temporary Shoring shown to be used in mu ltiple locations in conjunction with a structure will be considered as one location for lump sum payment. Unle ss shown as a bid item in the Contract Documents, the Engineer will not measure for payment any temporary shoring needed to comply with safety standards or due to the Contractor’s methods of operation. Payment for "Temporary Shoring" at the contract un it price is full compensation for the specified work. 702 – CONTROLLED DEMOLITION
700-2 Section 702
CONTROLLED DEMOLITION 702.1 DESCRIPTION Controlled demolition is the process of transporting, handling and disassembling the components of an open span structure to result in the complete or partial re moval of the entire structure or elements of a structure according to the approved demolition plan . The Contract Documents will identif y the category for each structure. Information on existing structures is made accessible by the Owner, if the information is available. Evaluate project characteristics and prepare demolition plans according to the specified category listed in the General Notes. Plan and execute all procedures nece ssary for full or partial removal of the structure in a safe and controlled manner that meets all applicable KDOT specifica tions and all applicable OSHA requirements. After concrete removal, or before any steel repairs, te st the paint for lead content. Properly handle any lead based paint. See SECTION 714 . 702.2 DEMOLITION SUPERVISOR The Demolition Supervisor is the person responsible for all rigging and handling of bridge primary and secondary members. The Demolition Supervisor shall be pr esent at the construction site during the removal of Category B & C Structures. All Demolition Supervisors must be pre-qualified for the scope, type and complexity of the existing structure. To become pre-qualified, provide proof of e xperience that the Demolition Supervisor has a minimum of 3 years of experience and at least 5 projects similar in scope, type and complexity. KDOT will maintain a list of approved Demo lition Supervisors on a Pre-Qualified List. Complete the pre-qualification of the Demolition Superv isor prior to the pre-construction meeting, and/or submit to the KDOT Field Engineer proof of pre-qualification at the pre-construction meeting. 702.3 DEMOLITION PLANS
a.General. The Contract Documents will indicate the demolition category for each structure. Submit shop drawings according to SECTION 105 . Develop a unique Demolition Plan for each qualifying existing open span structure in the Contract Documents. Submit a detailed Demolition Plan to the Owner’s Engi neer for each open span structure. Address all requirements for removal of the structure to the limits shown in the Contract Documents. Demolition may not proceed until a Demolition Plan has been approved. During phased/staged demolition, the Contractor’s responsibilities extend to the removal limits stated in the Contract Documents for each phase. Do not directly affect the remaining structure outside the removal limits for each phase, or affect th e adjacent structure. Include a Contingency Plan within the Demolition Plan indicating procedures to be carried out if the demolition stage completed does not comply with the Demolition Plan (i.e. the Plan states completion of rail removal, but due to unforeseen obstacles the majority of one rail has been partially disconnected from the existing structure, but it has not been removed).
b.Definitions. The level of review and the requirements for submittals by the Contractor to the Engineer are categorized by risk and complexity. The Design Engineer will determine and assign the Category of the demolition and will indicate the demolition Category for each open span structure requiring removal on the design plans. Signing and Lighting structures, due to the typical removal procedures, will sp ecify a demolition Category based upon the Signing and Lighting Engineer’s engineering judgment. If this information is erroneously omitted, contact the State Bridge Office (SBO). Special considerations will control the selection of the demolition Category. Controlled demolition of open span structures falls under three separate categories:
1.Category A. This category requires approval of a Demolition Plan. Demolition typically includes open span structures that w ill not carry any type of traffic during the de molition operations, stru ctures not adjacent to 702 – CONTROLLED DEMOLITION
700-3 traffic, or for structures that do not in clude a span over any type of traffic. Structures requiring phased removal will
be considered for Category A demolition.
2.Category B. This category requires approva l of a Demolition Plan, and a pre-qualified Demolition Supervisor. Demolition will include open span structures with more complex traffic control. Although the removal, or partial removal, may be simple in nature, the structure ma y continue to carry traffic, be located adjacent to traffic, or include one or more spans over traffic or railroad. Deck or rail replacement, partial depth patching, substructure repair projects or similar controlled demolition activities have the potential to become projects which require a more stringent demolition Category, and as such may be included in this Category.
3.Category C. This category requires an approved Demolition Plan reviewed by the SBO (or Bureau of Local Projects), a pre-qualified Demolitio n Supervisor, and the stamp of the Contractor’s Professional Engineer. Demolition is defined as the category for open span stru ctures with complex traffic control plans and removal sequences. Complex structures required to carry traffic during demolition ope rations, are adjacent to traffic, or structures that include one or more spans over traffic (c urved structures, severely skewed structures, multi-level interchange structures, etc.) may be included in this Category. A structure with components being removed over traffic or with the potential to fall into traffic is considered to be a Category C structure.
c.Submittals. Category A Demolition Plans. Provide the Field Engineer with one set of Demolition Plans before demolition begins. Demolition Plans will include at a minimum, as applicable:
1.A list of all equipment that will be used;
2.Sequence and limits of removal/partial removal/repair; (3) Measures to contain falling, or rolling, debris;
4.Heavy stockpile/equipment loads on the bridge, detailed in accordance with subsection 702.6 ; and
5.Traffic Control Plan Modi fication will be according to SECTION 805 . No additional requirements apply to this Demolition Category. Category B Demolition Plans. Provide the Field Engineer with one set of Demolition Plans 2 weeks prior to the demolition meeting. Meet each requirement for a Category A Demolition and at a minimum the following:
1.A removal sequence showing gravity loads imposed by Contractor equipment and materials. (2) Proposed methods of demolition, as applicable: A list of all equipment that will be used; Details of methods to brace the existing structure during demo process; Saw cut and/or break point locations; Crane pick locations, loads, positions, charts, and rigging; Location of protective covers or shields; Temporary drainage plan; and Proposed backfill after removal of below grade structures.
3.Specific details for removal will be clearly defined, as applicable: Practical environmental conditions limits for removal; Detailed Pick descriptions (Length, Center of Gravity, weight, etc.); Cross-frame or diaphragm removal sequence; and Temporary shoring/falsework details in compliance with SECTION 708 .
4.On the Demolition Plans, list the name of the person who is responsible for all rigging and handling of all elements requiring removal. This person, referred to as the Demolition Supervisor, must be present at the site during the demolition of all elements requiring removal. All field operations and field changes are under the authority and responsibility of the Contractor’s Demolition Supervisor.
5.Do not suspend/swing any elements over highway traffic at any time during any stage of the removal procedure. No additional requirements apply to this Demolition Category. 702 – CONTROLLED DEMOLITION
700-4 Category C Demolition Plans. Meet each requirement for a Category B Demolition. In addition, submit
the final Demolition Plan details, according to SECTION 105 , to the SBO (or Bureau of Local Projects) for review at least 4 weeks before the pre-demolition meeting.
1.The Engineer will require a pre-demolition meeting before any Category C demolition operations begin. The Demolition Supervisor will attend this pre-demolition m eeting to discuss any field concerns related to the demolition procedures and to increase familiarity with each existing structure to be removed.
2.Intermediate Stability. Defined as the point in time when the composite nature, or redundancy of the as-built structure, or elements of the structure, can no long er be relied upon to be stable under dead or live loads. This condition may be due to general or localized degradation of the structure, or due to demolition preparations. Before any connection between the existing structure and the element being removed has been compromised, provide protective stability measures for the existing struct ure, and for the element being removed. The existing state of the overall structural stability, or stability of particul ar elements of the structure, may be a major factor in the decision for complete, or partial removal. The composite nature and structural integrity of an as-built structure shall be verified before it is relied upon. This requires calculations, procedures and drawings to be developed and sealed by the Contractor’s Professional Engineer. Field changes causing increased lo ad effects at any controlling port ion of the structure must be approved and resealed by the Engineer who originally developed the plans before work begins. This work is under the authority of the Contractor’s Professional Engineer. In no case will the Engineer allow any type of traffic to travel under incomplete structures undergoing demolition without compliance of the Demolition Plan.
d.Calculations. Include the following as a minimum:
1.Calculations to substantiate structural adequ acy and stability for each st age of demolition, accounting for the structure’s lack of completene ss, various stages of partial connections, or complex structural geometry.
2.Primary member bearing calculations clearly stating minimum net downward forces at bearing locations at critical stages of removal.
3.Calculations to determine translations and rotations at intermediate removal conditions. (4) Design calculations indicating and verifying the load capacity and stability of all temporary supports, falsework bents, shields or covers, and bracing when used to allow traffic to travel under the incomplete structure.
5.Calculations indicating structural redundancy of the incomplete structure will be required at intermediate stages of demolition. These calculations w ill be required to account for unforeseen obstacles to the removal process that necessitate halting demolition at an undesignated stopping point.
6.Using alternative dead and live loading patterns producing the maximum load effect at controlling locations of the as-built structure, the Contractor’s En gineer may create an envelope of allowable means and methods for the demolition procedures. 702.4 DEMOLITION INFORMAT ION RESPONSIBI LITY SUMMARY The Contractor’s Engineer shall provide the following information (Category C): Plan of the work area showing the as-built perman ent support structures of the structure to be disconnected or removed, roads, railroad tracks, wa terways (including navigational channel), overhead and underground utilities and other information pertinent to the demolition procedure. Removal sequence for all elements of the structur e noting any temporary support conditions, such as holding crane positions, temporary supp orts or bracing, shoring, protec tive shields or covers, dead man cables, anchor blocks, etc. Details describing the number and location of the permanent, or temporary, cross-frames or diaphragms for each stage of removal. Details addressing the expected condition of each be aring device for each stage of construction. State the minimum number of positive bearing connections or supplemental connections to each bent cap which will resist potential destabilizing forces. Details addressing modified traffic control, utility and railroad issues. Demolition Plans to meet general falsework requirements in DIVISION 700 if falsework bents, temporary shoring, or strong-backs are used to maintain the stability of the remaining structure. 702 – CONTROLLED DEMOLITION
700-5 Contingency Plan specifying the various unintended partial stages of demolition and removal,
including end-of-day bracing and stability requirements. The Contractor’s Engineer will also need to address real-time concerns arising from the on-going demolition process. The Contractor’s Demolition Superv isor shall provide the following information (Category B or C): Verification to the Contractor and the Field Engineer that member reference marks, as described in the Demolition Plan, have been transferred to the existin g structure to allow the Contractor and the Field Engineer to conduct a field review; Limits for windspeed/gust, or other environmental concerns for crane operations; Proposed crane locations for primary pick s showing all necessary information; Capacity chart for each crane configuration; Center of gravity, lift weight (including rigging) for all picks; Primary/secondary element removal location and storage; Details of any temporary lifting devices to be bolted/welded to permanent members, including stage and method of attachment, capacity, and stage of removal and Temporary support details for bridge bearings. The Owner’s Inspector shall require th e following (Category A, B and C): A dimensionally accurate Demolition Pl an, clearly stating the limits of removal, girder line locations, etc., to permanently transfer to the existing structure; Requirements for bracing. At the en d of each workday, remove, or te mporarily brace, the structural elements not properly stabilized to bring these elements into compliance with the Demolition Contingency Plan; and All rigging must have capacity stamps, tags or be otherwise permanently marked on the device (per OSHA Standards). 702.5 PRECONSTRUCTION CONFERENCE Discuss the Demolition Plan at the pre-construction or pre-demolition meeting. Resolve any questions during the meeting concerning the Demolition Plan or specific demolition procedures to the satisfaction of the Contractor, Contracto r’s personnel, and the Engineer before demolition begins. Additional circumstances may be addressed to include within the Contingency Plan. Modify the Contingency Plan to include all situations agreed upon during the meeting. 702.6 CONSTRUCTION REQUIREMENTS Do not perform any demolition work without an approved Demolition Plan. Keep the approved Demolition Plans available on site at all times. Maintain a consistent, core group of staff (superviso rs and laborers) through the completion of demolition. Demolish the existing structure and perform all work required to remove the structure to the limits stated and as detailed in the Contract Documents. Upon completion of the demolition, remove all obstructions or debris resulting from these operations. Without prior written approval by the KDOT Area Engi neer, do not stock pile construction materials, debris, or rubble exceeding the lesser of the posted load limit, or 20 tons. Equipment on the structure must not exceed the lesser of the poste d load limit, or the Operating Load Rati ng for the structure. To request written approval, provide the KDOT Area Engi neer plans showing the location, quantity and weight of the proposed materials, debris and/or equipm ent exceeding the stated limits. Perform demolition in a reasonable, controlled, met hodical fashion. Demolition Plan approval by the Engineer will not and does not relieve the Contractor of the responsibility for the safety of the methods used, safety of the equipment, or from carrying out the work in full accordance with SECTION 107 . Demolition is complete when all elements are removed to the limits shown in the Contract Documents and any shoring and debris are removed. 702.7 MEASUREMENT AND PAYMENT The Engineer will not measure Controlled Demolition, Demolition Plans and Contingency Plans for separate payment. All required work is subsid iary to the other bridge items in the contract. 703 - DRILLED SHAFTS
700-6 Section 703
DRILLED SHAFTS 703.1 DESCRIPTION Construct drilled shafts by the cased or uncased method depending upon site conditions and Contract Document requirements. BID ITEMS UNITS Drilled Shaft (*) (**) Linear Foot Permanent Casing (*) (Set Price) Linear Foot Sonic Test (Drilled Shaft) (Set Price) Each Core Hole (Investigative) Linear Foot *Size **Cased (If Contract Documents specify the cased method.) 703.2 MATERIALS
a.Concrete. Unless otherwise shown in the Contract Documents, provide Grade 4.0 concrete that complies with SECTIONS 401, 402 and 1102 . Provide a mix design with a target slump of 9 inches ± 1 inch. Do not withhold mix water at the plant and do not add water at the site.
b.Grout/Flowable Fill. For backfilling the cross-hole sonic testing pipes and core holes, provide cementitious grout (mixed according to the manufacturer’s directions) that complies with DIVISION 1700 . Provide grout or flowable fill for backfilling the void space between the temporary and permanent casing with: 28 day strength of 1000 psi; mortar sand, FA-M ( SECTION 1102 ) mixed with 2 bags of Type II portland cement per cubic yard; and water-to-cement ratio less than 1.
c.Granular Backfill Material. Provide granular backfill material for backfilling the void space between the temporary and permanent casing that is fine enough to fill the entire volume. The Engineer will accept the granular material based on a visual inspection.
d.Reinforcing Steel. Provide steel bars for concrete reinforcement that comply with DIVISION 1600 .
e.Casing. Provide casing of sufficient thickness to carry the working stresses and loads imposed on the casing during construction. At a minimum, use 14-gage co rrugated metal pipe (CMP) fo r the permanent casing. If required, provide a permanent casing that is less than or equal to 1 inch out-of-round. The deviation of a chord from end to end shall be a maximum of 2 inches. The Engineer will accept the casing based on compli ance with the specified requirements, and visual inspection for condition.
f.Pipe for Sonic Testing. Provide pipe that complies with DIVISION 1900 . 703.3 CONSTRUCTION REQUIREMENTS
a.General. Drilled shaft lengths shown in the Contract Documents are an estimate from the top of formation elevations determined from borings. Actual fo rmation elevations encountered at each shaft, may require the actual length of each drilled shaft be adjusted. If the Engineer changes th e drilled shaft lengths, the Contractor will be advised (in writing) of the revi sed bottom of rock socket elevation. A minimum of 28 days before constructing the drilled shafts, submit an installation plan to the Engineer for review. Include the following: Name and experience record of the drilled shaft supe rintendent in charge of drilled shaft operations; 703 - DRILLED SHAFTS
700-7 List of proposed equipment, such as cranes, drills, augers, bailing buckets, fi nal cleaning equipment, de-
sanding equipment, slurry pumps, core-sampling equi pment, tremies or concrete pumps and casing; and Details of concrete placement, including proposed operational procedures for tremie and pumping methods and method of achieving a sealed tremie or pump.
b.Investigative Core Hole. Provide NX sized (2.125 inches) core samples organized in descending elevation and stored in standard core cardboard boxes. Perform this work, from the existing ground surface elevation, 15 working days in advance of the drilled shaft construction, at locations shown in the Contract Documents or ordered by the Engineer. Extract and maintain a core of the foundation material from 4 feet above the top of the plan tip elevation to 6 feet below the plan tip elevation shown in the Contra ct Documents. Discard all material extracted above 4 feet above th e top of the plan tip elevation. Maintain, protect and label (elevation and location) these samples for review by the KDOT. While dr illing, prepare a continuous standard drilling/coring log. The logs shall remain with the sample for review. Survey the location of the core hole with the same construction tolerance as subsection 703.3c .
c.Excavating the Drilled Shaft. Prior to constructing drilled shafts, complete the excavation for the entire element. Locate the top of the shaft within 2 inches of the location shown in the Contract Documents. Unless otherwise shown in the Contract Documents, bore all shafts plumb to within a tolerance of 1 inch per 10 feet of length of shaft, not to exceed 6 inches over the full length of the shaft. The bottom of the shaft shall be nearly flat. The cutting edges of excavation equipment shall be normal to the vertical axis of the equipment within a tolerance of ±⅜ inch per foot of diameter. Depending upon site conditions and re quirements in the Contract Documents, construct the drilled shaft by either the cased or uncased method: (1) Uncased Method. Use this method at locations anticipated to be free of caving soil or excess water inflow into the excavated shaf t. Do not use the uncased method if the act ual conditions show the shaft is prone to caving soil, or has water inflow that exceeds the dry pour method requirements in subsection 703.3f . Excavate the shaft without the use of added water or drilling fluid. Completely excavate the shaft in a continuous operation, unless encoun tering rock or obstructions. Place the concrete without delay.
2.Cased Method. Use this method at locations with caving soil or excess water inflow into the excavated shaft. Use either a permanent smooth, thick-walled casing, or a combination of a smooth, thick-walled temporary and permanent CMP casing together. All permanent casings shall be watertight. Advancing shaft excavation by stabiliz ing the hole with drilling fluid is acceptable. Do not allow drilling fluid to get into the rock socket. The concrete placement method used in a cased sh aft depends on the water inflow requirements in subsection 703.3f . After removal of the overburden, complete the excava tion below the top of rock as an uncased core (rock socket) of the diameter shown in the Contract Documents. Do not excavate closely spaced dr illed shafts (3 drilled shaft diameter s or less, center to center) until adjacent shafts are completed and cure d according to the following criteria: Completed shafts have been allowed to set for a minimum of 24 hours after the concrete placement; and Developed a compressive strength of 1800 psi; or Without testing, the Engineer may allow excavation to proceed when the shaft has cured 72 hours after completion of the concrete placement. If the Contract Documents specify or the Contractor elects to use pe rmanent thick-walled casing for the closely spaced shafts, the Contractor may excavate multip le closely spaced drilled shaf ts. Once the concrete is placed, it must be cured according to the criteria above be fore excavating additional clos ely spaced drilled shafts. For drilled shafts equal to or greater than 72 inches in diameter founded in shale, or as required in the Bridge Foundation Geology Report, perform the following, prior to placement of the reinforcing cage: Use a full diameter flight auger or core barrel. Exte nsions to the auger to increase the diameter of the hole are prohibited, except when excavating a belle d rock socket with an under ream attachment; Use a full size, clean-out bucket a minimum of 95% of the diameter of the rock socket, when needed; 703 - DRILLED SHAFTS
700-8 In the presence of the Engineer, sound the bottom of the finished shaft. Use a weighted tape in a 12-
inch grid across the base of the shaft; Provide access to the entire perimeter of the shaft; Flocculate the finished shaft to increase the visibility in the water, prior to using the underwater video camera. Use a commercially available floccule nt agent per the manufacture’s recommendations. Prior to concrete placement, perform a video inspec tion to inspect the sides and base of the rock socket. Along with the Engineer, review the video to verify the socket meets th e cleanliness portion of this specification, prior to concrete placement; Perform sonic testing for all shafts. Submit test results to the Chief Geologist for review. No work will be done above the top of drilled shaft withou t the approval of the Chief Geologist; and Any required repairs or additional testing are the Contractor’s expense.
d.Placing Reinforcing Steel and Sonic Testing Pipes. Tie reinforcing steel at all intersections of reinforcement, and place reinfo rcing steel as a unit for the full length of the shaft, prior to placing any concrete by either pour method. Use a minimum of 1 non-corrosive ci rcular spacer per 30 inches of circumference of the reinforcing steel cage, within 2 to 4 feet of the bottom and top, and at intervals not to exceed 10 feet vertically. If the shaft is deepened and additional reinforcing steel cage is required, make the splice at the bottom of the steel cage. Remove any corrosion protection coating from the sonic testing pipes by sandblasting. Sandblast the pipes to bare metal. Place the sonic testing pi pes within 7 days of sandblasting. In each shaft, place the number of testing pipes shown in the Contract Documents. All sonic testing pipes shall be the full length of the shaft from the bottom of the rock socket a minimum of 12 inches above the top of the shaft concrete. Before placement, measure and record the le ngth of the sonic testing pipes and elevation of any pipe joints. If multiple sections of pipe are required to reach the full length, the joints shall be watertight. The joints for all testing pipes in the shaft shall be at the same elevation. Completely seal the bottom of the pipe. After installation, fill pipes with potable water and install threaded caps. All testing pipes shall remain watertight until testing is complete. Regardless of the connection used, conduct a pressu re test of each pipe upon installation in the reinforcement cage. Test all pipes after being placed and tied in the reinfo rcement cage. When the drilled shaft is greater than 30 feet in length, perform a second pr essure test after the reinforcement and pipes are installed in the drilled shaft but prior to placing the concrete. Pressurize the pipe to 100 psi. Seal the pipe for 3 minutes. Pressure loss can not be greater than 5% in 3 minutes.
e.Final Inspection and Access. At the time of placing the concrete, a minimum of 75% of the base of the shaft must have less than ½ inch of sediment. The Engi neer will determine the shaft cleanliness before concrete placement by: Visual inspection; or Underwater inspection using probes; or Down hole television camera and video recordings Provide access to 100% of the hole from probing purposes. Probing will be done by a tape with a minimum weight of 1 pound. Review and inspection by the Engineer prior to concrete placement does not relieve the Contractor of the responsibility for producing a defect-free shaft per specifications. When directed by the Engineer, opera te the camera and recorder such that the optimum clarity of the details can be obtained and all surface areas of the shaft, including th e rock socket sides and base can be observed. Record video and store tapes such that later review is possible. Label the recorded media, which will become the property of KDOT.
f.Placing Drilled Shaft Concrete. Depending upon site conditions, place concrete by either the dry pour or wet pour method: Use the dry pour method if water inflow does not fill the shaft more than 4 inches in depth in a 5 minute period, and the shaft can be dewatered so a maximum of 2 inches of water is standing in the shaft when concrete placement begins. 703 - DRILLED SHAFTS
700-9 When the above 2 conditions can not be met, use the wet pour method.
For both the dry and wet pour met hods, the following common requirements for concrete placed in a cased or uncased shaft shall apply: Target slump is 9 inches ± 1 inch; Place concrete in the shaft with a contin uous operation, without construction joints; Do not vibrate concrete; Determine the top elevation of the fresh concrete and inform the Engineer; and Do not use aluminum concrete pump discharge tubes or tremie tubes.
1.Dry Pour Method. Use a centering device to deposit concrete so the falling concrete shall not come into contact with vertical and horizontal re inforcing steel and wire supports. To control the fall, extend the centering device a minimum of 8 feet into the shaft. For a cased sh aft, concrete may free fall to the bottom. For an uncased shaft, the maximum fall for concrete is 5 feet.
2.Wet Pour Method. Prior to starting concrete placement, allow the water level in the shaft to reach its static level. Place concrete with either a sealed (wat ertight) tremie tube or pump with a rigid and watertight extension tube. In either case, use a device (i.e. commercially available pig or flap gate) that prevents water from entering the tube while charging with concrete. The commercially available pig shall be a minimum of 110% the diameter of the tube. Clearly label the outside of the tremie and pump tubes in 12-inch increments (starting at the bottom). Lower the rigid tube into the shaft with the bottom of the tube resting on the bottom of the rock socket, and fully charge the system (tube and hopper or pumping system) w ith concrete. Once the system is fully charged, raise the tube off the bottom of the rock socket by 1 tube diameter, a nd allow the concrete to seal the discharge end of the tube. Maintain the tube at this elevation until a minimum of 7-foot head of concrete is developed. Maintain a minimum 7- foot head of concrete during the concrete placement. Prior to raising the tube, determine the top elevation of the fresh concrete and inform the Engineer. For wet pours, follow the steps listed in the previous paragraph, regardless of the Method (A, B or C) used to place concrete in the shaft: 703 - DRILLED SHAFTS 700-10 Method A (Figure 1): Use a pump and extension tube, with a pig separating the ground water and concrete, to place concrete into the shaft. Install a c oncrete brake (e.g. bladder valve or French horn) at the end of the pump boom to purge the air from the pump line. Fully charge the boom with concrete (no air gaps) then install the pig in the top of the extension tube. Method B (Figure 2): Use a tremie tube, with a pig separating the ground water and concrete, to place concrete into the shaft. Once the tremie tube is res ting on the bottom of the shaft, install the pig just below 703 - DRILLED SHAFTS
700-11 the hopper in the top of the tremie tube. Fully charge the tremie tube and hopper (forcing the pig to the
bottom of the tremie tube), then raise the tremie tube by 1 tremie diameter and seal the discharge end of the tremie tube with the fresh concrete. Method C (Figure 3): Use a tremie tube, with a sealed gate se parating ground water and concrete, to place concrete in the shaft. Fully charge the tremie tube and hopper, then raise the tremie tube by 1 tremie diameter and seal the discharge end of th e tremie tube with the fresh concrete. When the concrete reaches the top of the shaft, con tinue placing concrete (over-p ump) to expel any excess water, debris or unsound concrete. If the casing extends ab ove the planned shaft elevation the excess material must be expelled by providing an outlet in the casing above the planned elevation if the shaft. Do not bail the excess material out of the shaft. On all wet pours, regardless of the method us ed, the Engineer will make a set of cylinders (in addition to normal concrete cylinder sampling requirements) from the top of the shaft after completing over-pumping. This set of cylinders will be used to verify a compressive strength of 1800 psi before proceeding with subsequent substructure (i.e. columns, abutments, etc.) construction. Prior to constructing the portion of the substructure th at attaches to the drilled shaft, thoroughly clean the top of the drilled shaft to facilitate the bond at the cold joint.
g.Raising Temporary Casing. Do not remove the temporary casing until the concrete in the shaft has met the following conditions: Completed shafts have been allowed to set for a minimum of 24 hours after the concrete placement; and Developed a compressive strength of 1800 psi; or If compressive strength does not meet 1800 psi, the Engineer may a llow the Contractor to proceed when the shaft has cured 5 days after completion of the concrete placement. However, immediately after completing concrete place ment in the permanent cas ing, it is acceptable to raise and hold the temporary casing at the embedment depth plus 6 inches. Before raising the temporary casing completely, b ackfill the space between the 2 casings according to subsection 703.3j .
h.Curing. Cure the exposed surfaces of th e shafts with wet burlap a minimum of 2 days. Do not use liquid membrane curing. Cure all cylinders in the field, alongside and under the same conditions as the concrete they represent. 703 - DRILLED SHAFTS
700-12 i. Sonic Testing.
1.General. Perform sonic testing on all drilled shafts constructed by the wet pour method. Perform sonic testing on any dry pour method as directed by the Engineer. Conduct the sonic testing between 2 and 21 days after the drilled shaft is completed. The Engineer has the option to require additional testing. Secure the services of an independent, experienced test ing organization to take the cross-hole sonic logging measurements and issue reports. Submit to the Engineer, the testing organization’s record of experience, a written description of the testing procedures, operation manuals for th e testing equipment, and samples of previous test results indicating both sound and defective concrete.
2.Sonic Logging Equipment. Provide sonic logging equipment capable of identifying any faults, honeycombing or poor concrete at KDOT specified operating settings: A time base that shall provide the “zero signal” and “first arrival” are 2 to 3 divisions apart on the horizontal axis; and Select a gain to produce an amplitude signal that fills ⅔ to ¾ of the screen along the vertical access of the waveform plot for portions of the shaft that correspond to good quality concrete; Provide test results on thermal or graphical printouts w ith the vertical scale repres enting the vertical position along shaft, and the horizontal scale representing the propagation time.
3.Sonic Logging Test Procedure. Immediately prior to testing, verify the pipes are free from blockages and filled with water. Determine the el evation of the top of the drilled shaft and the top of each pipe. Measure each pipe to determine the depth, and provide the information to the Engineer. Conduct the sonic logging test procedure between all possible combinations of pipes (i.e. 4 pipes have 6 different combinations, 5 pipes have 10 different combinations, 6 pipes have 15 different combinations, 7 pipes have 21 different combinations, 8 pipes have 28 different combinations, etc.). If the sonic testing detects faults, the Engineer may require retesting with the probes in the same or different horizontal plane. The testing organization shall make suggestions for changes in the Crosshole Sonic Logging (CSL) testing procedure based on known shaft construc tion issues or survey access issues. Su ch changes could include, but would not be limited to changing the frequency of data collection along the length of the shaft or offsetting the transducers from the horizontal plane. Any such suggested changes in CSL data collection proced ures must be approved in advance by the Engineer. Immediately prior to testing, verify the pipes are free from blockages and filled with water. Determine the elevation of the top of the drilled shaft and the top of each pipe. Plumb each pipe to determine the depth, and provide the information to the Engineer. Configure sonic logging to settings in subsection 703.3i.(2) . Use a winch to simultaneously raise the probes from the bottom of the pipes at a maximum rate of 12 inches per second. Take all slack out of the cables before switching on the analyzer.
4.Record of Testing. After completing sonic testi ng, provide the Chief Geologist the report of the CSL test results stamped by a licensed Professional Engineer that includes data plots (recorded on thermal or graphical printouts) with the profiles referenced to the top of the shaf t or top of the pipe elevation. A copy of the report shall be sent by the testing organization to the Contractor. No work shall be done above the top of the drilled shaft without approval from the Chief Geologist. Inform the Engineer on site of any faults, honeycombing or poor concrete detected by a fainting of the signals and a sudden lengthening of the propagation time. Diagram (horizontal and vertical cross-sections) any defect s found within the shaft to identify the location, width and thickness of the defect. Provide the report of CSL results, stamped by a licensed Professional Engineer, within 1 week of conducting the sonic test. The CSL practitioner does not have the information available to make recommendations for shaft acceptance or correction as pa rt of the normal course of testing a shaft.
5.Coring. If the sonic logging inspection indicates an anomaly for any zone of the shaft represented by loss of signal, a reduction in apparent sonic velocity greater than 15%, or where the velocity is equal to or less than 15% and as directed by the Chief Geologist, or where a survey was not complete due to problems associated with access tubes, drill cores (NX size, 2.125 inches or larger) at lo cations and depths approved by the Engineer. Dr ill cores NX size (2.125 inches, or larger), however if the location of the an omaly prevents an NX size core , with the approval of the Engineer, drill a smaller size (minimum A size, 1.25 inch) core. Mark the beginning and end of each core and record the total length of the core and the total length recovered, co re recover must be greater than 95%. Provide the Engineer the recorded information and the core sa mples labeled with their location and re lative elevation. If the concrete is defective, submit a written proposal to repair the drilled shaf t. The proposal must be a pproved by the Engineer before repairs commence. 703 - DRILLED SHAFTS
700-13 (6) Filling Core Holes. Fill core holes by pre ssure grouting with non-shrink grout described in subsection
703.2b . Use a pipe extending to the bottom of the hole to fill it from the bottom to the top.
7.Filling Pipes. After completing sonic testing and final acceptance of the drilled shaft is made, fill the sonic testing pipes with the specified non-shrink grout. If the Contractor can expel enough water from sonic testing pipes leaving 2 feet or less of standing water in the sonic testing pipe, grout may free fall to the bottom of the pipe. If more than 2 feet of water remains in the bottom of the sonic testing pipe, prevent the grout from free falling through the water using a tremie tube extending to the bottom of the sonic testing pipe.
j.Backfill. When a temporary casing and a permanent casing are used, backfill the space (between casings) with the material specifi ed in the Contract Documents: Granular material fine enough to fill the entire volume; or Grout or flowable fill described in subsection 703.2b . If the space contains water, use a pump with an exte nsion pipe or tremie (extending to the bottom of the space) to fill the space. If the space is dry, the grout/f lowable fill may free fall to th e bottom of the shaft. Fill the space with grout/flowable fill to the to p of the casing, then, completely remove the temporary casing. When the Contract Documents do not specify a material for backfill, use the granular material before extracting the temporary casing. After extracting the temporary casing, fill th e rest of the space with granular material. 703.4 MEASUREMENT AND PAYMENT
a.Drilled Shafts. The Engineer will measure drilled shafts by th e linear foot measured from the bottom of the rock socket to the top of the completed drilled shaft. The Engineer will not consider a request for additional compensation, unless the overall length of a drilled shaft changes by more than 20%.
b.Permanent Casing. The Engineer will measure the accepted permanent casing by the linear foot, if a permanent casing is required, but not specified in the Co ntract Documents. The Engineer will not measure the permanent casing if: Contract Documents requir e Drilled Shafts (Cased). Contractor uses the casing for their convenience. Casing is a temporary casing.
c.Sonic Test (Drilled Shaft) (Set Price).
1.Sonic Testing specified in Contract Documents. When shown in the Contract Documents, the Engineer will measure each designated sonic test, per shaft (i.e. so nic logging between all possi ble combinations of pipes represents a single sonic test).
2.Sonic Testing requested by the Engineer. When the Engineer requests sonic tests not shown in the Contract Documents, and the sonic testing indicates the concrete is acceptable, the Engineer will measure each sonic test, per shaft (i.e. sonic logging between all possible combinations of pipes represents a single sonic test). When the Engineer requests sonic testing not shown in the Contract Documents, and the sonic testing indicates defective concrete in the drilled shaft, the Engineer will not measure for payment the sonic testing of that shaft. When the Engineer requests sonic testing not shown in the Contract Documents, the sonic testing indicates defective concrete in the drilled shaft, th e Engineer requests cores from the shaft, and the cores reveal unsound concrete, the Engineer will not measure for payment the sonic testing or cores for that shaft. When the Engineer requests sonic testing not shown in the Contract Documents, the sonic testing indicates defective concrete in the drilled shaft, and the Engineer requests cores from the shaft, and the cores reveal sound concrete, the Engineer will measur e for payment each sonic test, per shaft (i.e. sonic logging between all possible combinations of pipes represents a single sonic test). The Engineer will also pay for the cores as Extra Work according to SECTION 104 .
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 323–344 of 978.