933-1 Strands for Prestressing.
933-1.1 Carbon Steel Strands for Prestressing: The carbon -steel strands for
prestressing concrete members shall be Grade 270, low-relaxation seven wire strand conforming to the requirements of ASTM A416.
933-1.2 Stainless-Steel Strands for Prestressing: The stainless -steel strands for
prestressing concrete members shall be a high strength stainless-steel (HSSS , Grade 240), low-relaxation seven wire strand conforming to the requirements of ASTM A1114.
933-1.3 Carbon -Fiber-Reinforced Polymer (CFRP) Strands for Prestressing: Obtain
CFRP prestressing strands from producers currently on the Department’s Production Facility Listing. Producers seeking inclusion on the list shall meet the requirements of Section 105. CFRP strand shall meet the requirements of this Section. Table 933-1 Typical Sizes and Loads of CFRP Prestressing Strands and Bars Type Nominal Diameter (in) Nominal Cross Sectional Area (in2) Nominal Ultimate Load (Pu) (kips) Nominal Ultimate Tensile Stress (ksi) Single Strand - 5.0mm Ø 0.20 0.025 9.1 364 7-strand - 7.9mm Ø 0.31 0.048 17.8 370 7-strand - 10.8mm Ø 0.43 0.090 33.1 367 Single Strand (Bar) - 9.5mm Ø 0.38 0.110 35.0 318 7-strand - 12.5mm Ø 0.49 0.117 43.3 370 Single Strand (Bar) - 12.7mm Ø 0.50 0.196 59.0 301 7-strand - 15.2mm Ø 0.60 0.179 66.2 369 7-strand - 17.2mm Ø 0.68 0.234 86.6 370 7-strand - 19.3mm Ø 0.76 0.289 106.9 370
933-1.4 Shipping and Storage: Protect carbon -steel, stainless -steel, and CFRP strands
for prestressing against mechanical damage and contamination during shipping and storage .
933-2 Steel Bars for Prestressing.
The steel bars for prestressing concrete mem bers shall conform to the requirements of ASTM A722, Type II.
933-3 Steel Parallel Wire Assemblies for Prestressing.
The wire assemblies for prestressing concrete members shall consist of parallel wires of the number and size shown in the Plans and shall conform to the requirements of ASTM A421.
933-4 Anchorages for Prestressing.
933-4.1 For Strands and Bars:
FY 2023-24 Return to Table of Contents
933-4.1 1 Steel Strands and Bars: Meet the requirements of Section 960.
933-4.1 2 Carbon Fiber Reinforced Polymer (CFRP) Strands: Meet the
requirements of ACI 440.3R, B.10 – Test method for performance of anchorages of FRP bars.
933-4.2 For Steel Parallel Wire Assemblies: Anchorage for parallel wire assemblies
may be provided by Type BA (Button Anchorages) cold -end deformation of the wires b earing against suitable anchorage plates, or by Type WA (Wedge -type Anchorages ) without cold end deformations, of the sandwich -plate or conical type. The anchorage device shall be capable of developing at least 90% of the specified ultimate strength of the total number of wires anchored. Conical type anchorages shall be embedded within the ends of the concrete members unless otherwise specified. Anchorages shall generally bear against embedded grids of reinforcing steel of approved type. Alternate type anchorages will be considered if proposed by the Contractor. Any alternate anchorage will be required to develop the full specified ultimate strength for bars or at least 90% of the specified ultimate strength for parallel wire assemblies.
933-5 Required Tests for Prestressing St rand and Bar .
933-5.1 General: Tests shall be performed to determine the physical characteristics of
prestressing reinforcement. For tests specified to be made by the producer, submit certified test results to the Engineer prior to use .
933-5.2 Strands:
933-5.2 1 Steel Strands: Acceptance of carbon -steel and stainless -steel
prestressing strands shall be based on samples taken by the Department and the producer’s certified mill analysis certifying that the test resu lts meet the specification limits of ASTM, AASHTO, or FDOT as specifically designated. Prior to use, submit to the Engineer the producer’s certified mill analysis for each heat or production LOT per shipment of strand. Certified mill analyses for steel prestressing strand shall contain, for each heat number or production LOT, all test results required by ASTM A416 and ASTM A1114. Include the modulus of elasticity expressed in psi or the stress -strain curve with units identified. The Engineer will sele ct samples and certified mill analysis representing each shipment at a frequency of one sample per producer, per size of strand, per shipment.
933-5.2 2 Carbon-Fiber-Reinforced Polymer (CFRP) Strands: Producers shall
submit to the State Materials Office (SMO), a test report of the physical and mechanical property requirements in Table 933-2. Qualification testing shall be conducted by an independent laboratory approved by the Department for performing the FRP test meth ods. Three production LOTS shall be randomly sampled at the production facility by a designee of the SMO. The minimum number of specimens per production LOT shall be as indicated in Table 933-2. The coefficient of variation (COV) for each test result shall be less than 6%. Outliers shall be subject to further investigation in accordance with ASTM E178. If the COV exceeds 6%, the number of test specimens per production LOT may be doubled a maximum of two times, to meet the COV requirement. Otherwise, the res ults shall be rejected. A production LOT is defined as a LOT of CFRP strand produced from start to finish with the same constituent materials used in the same proportions without changing any production parameter, such as cure temperature or line speed . FY 2023-24 Return to Table of Contents Table 933-2 Physical and Mechanical Property Requirements for CFRP Prestressing Strands Property Test Method Requirement Specimens per LOT Fiber Mass Fraction ASTM D2584 or ASTM D3171 ≥70% 10 Short-Term Moisture Absorption ASTM D570, Procedure 7.1; 24 hours immersion at 122°F ≤0. 25% 10 Long-Term Moisture Absorption ASTM D570, Procedure 7.4; immersion to full saturation at 122°F ≤1.0% 10 Glass Transition Temperature ( Tg) ASTM D7028 (DMA) or ASTM E1356 (DSC; Tm)/ASTM D3418 (DSC; Tmg) ≥230°F ≥212°F 3 Total Enthalpy of Polymerization (Resin) ASTM E2160 Identify the resin system used for each bar size and r eport the average value of three replicates for each system - Degree of Cure ASTM E2160 ≥95% of T otal polymerization enthalpy 3 Measured Cross Sectional Area ASTM D7205 Within -5% to +10% of nominal values listed in Table 933-1 10 Ultimate Tensile Strength (UTS) ≥ Value listed in Table 933-1 Tensile Modulus ≥18,000 ksi for Bar; > 22,400 ksi for 7-strand & 5mm Ø. Alkali Resistance with Load ASTM D7705, 3 months test duration at 140 ± 5°F. Apply sustained tensile stress to induce 3000 micro -strain, followed by tensile test per ASTM D7205 Tensile strength retention ≥70% of UTS 5 Creep Rupture Strength ASTM D7337, 3 months test duration at laboratory conditions. Apply sustained tensile load equivalent to 75% UTS, followed by tensile test per ASTM D7205 Equivalent sustained load ≥75% UTS AND Tensile strength retention ≥90% UTS 3
933-5.2 2.1 Material Acceptance : Submit to the Engineer a certificat e of
analysis for each production LOT from the producer of the CFRP strand, confirming compliance with the requirements of this Section. FY 2023-24 Return to Table of Contents
933-5.2 2.2 Sampling: The Engineer will select a minimum total of
42 feet from each shipment, representing a random production LOT , per size of CFRP strand for testing in accordance with Table 933-3. The minimum discrete sample length s hall be 7 feet. Testing shall be conducted, at the Contractor’s expen se, by a Department approved independent laboratory . Each test shall be replicated a minimum of three times per sample. Submit the test results to the Engineer for review and approval prior to installation . Table 933-3 Testing requirements for Pro ject Material Acceptance of CFRP Prestressing Strand Property Test Method Requirement Fiber Mass Fraction ASTM D2584 or ASTM D3171 ≥70% Short-Term Moisture Absorption ASTM D570, Procedure 7.1; 24 hours immersion at 122°F ≤0.25% Glass Transition Temperature ASTM D7028 (DMA) or ASTM E1356 (DSC; Tm)/ASTM D3418 (DSC; Tmg) ≥230°F ≥212°F Degree of Cure ASTM E2160 ≥95% of Total polymerization enthalpy Actual Cross Sectional Area ASTM D7205 Within -5% to +10% of nominal values listed in Table 933-1 Ultimate Tensile Strength ≥ Value listed in Table 933-1 Tensile Modulus ≥18,000 ksi for Bar; > 22,400 ksi for 7 - strand & 5mm Ø
933-5.3 Steel Bars: Acceptance of steel prestressing bar shall be based on samples taken
by the Department and the producer’s certified mill analysis certifying that the test results meet specification limits of the ASTM or AASHTO as specifically designated. Prior to use, submit to the Engineer the producer’s certified mill analysis for each heat or production LOT and size per shipment of bars. Certifications of steel prestressing bar shall contain, for each heat number o r production LOT, all test results required by ASTM A722 and the modulus of elasticity expressed in psi or the stress -strain curve with units identified. The Engineer will select samples and certified mill analysis representing each shipment at a frequency of one sample per heat or production LOT, per size of bar, per shipment.
933-5.4 Steel Wires: Acceptance of steel wires shall be based on the producer’s certified
mill analysis of test results meeting the specification limits of the ASTM or AASHTO as specifically designated. Prior to use, submit to the Engineer the producer’s certified mill analysis for each heat or production LOT per shipment of wire. Certifications of steel prestressing wire shall contain, for each heat number o r production LOT, all test results required by ASTM A421. FY 2023-24 Return to Table of Contents SECTION 934 NON-SHRINK GROUT
934-1 Scope.
This Section covers only prepackaged non -shrink cementitious grout for structural use.
934-2 Type Permitted.
Only non -metallic formulations of grouts are allowed. Gas producing, metal oxidizing and expansive aggregate grouts are not allowed.
934-3 Sampling and Testing Methods.
Perform concrete sampling and testing in accordance with the following methods: Making and Curing Concrete Test Specimens in the Laboratory ................................ ............... ASTM C192 Time of Setting Concrete Mixtures by Penetration Resistance ................................ ...... ASTM C403 Determining Low -Levels of Chloride in Concrete and Raw Materials ................................ ....................... FM 5-516 Compressi ve Strength of Hydraulic Cement Mortars ................................ .............................. ASTM C109 Flow of Grout for Preplaced Aggregate Concret e (Flow Cone Method) ................................ ......... ASTM C939 Measuring Changes in Heigh t of Cylindrical Specimens from Hydraulic Cement Grout ................................ . ASTM C1090 Expansion and Bleeding of Freshly Mixed Grout for Preplaced Aggregate Concrete in the Laboratory .............. ASTM C940
934-4 Requirements.
When tested as provided in 934 -3, the grout shall meet the following requirements: Table 934-1 Property Test Value Compressive strength one day 2,500 psi minimum 3 days 5,000 psi minimum Time of set, final 8 hours maximum Chloride Content 0.40lb/yd3 maximum Hardened Height Change at 1, 3, 14, and 28 Days 0.0% to 0.3% Hardened Height Change at 1, 3, and 14 Days Height Change @ 28 Days Expansion 2.0% @ 3 Hours Bleeding, Final 0.0% @ 3 Hours FY 2023-24 Return to Table of Contents