ULTRA HIGH -PERFORMANCE CONCRETE SECTION 614 264 SECTION 614 – ULTRA HIGH -PERFORMANCE CONCRETE
614.1Description
This work consists of providing, mixing, transporting, placing, finishing, curing, and grinding Ultra High - Performance Concrete (UHPC).
614.2Materials
A.Fine Aggregate
1.Use crushed quartz with 100% passing the No. 30 sieve and a maximum of 3% passing the No.
200 sieve.
B.PCC Section 102 0
C.Steel Fibers ASTM A820, Type 1
1.Closure Pours 2 percent by volume
D.Water and Ice Section 1021
E.Admixtures As required by manufacturer.
F.Liquid Membrane Compounds Section 1045.7
G.Polyethylene Sheeting Section 1022.6.B
614.3Construction
1 Submittals
A.Submit trial batch of UHPC per 1025.3.A.
B.Submit a Quality Control Plan to verify that all materials, equipment, and workmanship meet the
contract requirements. Provide detailed personnel, equipment, methods, sequence, and procedures to ensure the specified quality of all applicable materials a nd related field operations. Follow the submittal procedures outlined in Section 105.4. Provide the following information in the plan, as applicable:
1.Batch proportions, production sequence, and production rates.
2.Allowable ambient temperature and weather conditions for mixing and placement.
3.Construction loads with locations applied to the bridge during UHPC placement.
4.Surface preparation procedures, including cleaning and pre -wetting.
5.When performing closure pours, provide:
a.Formwork information, including materials and removal.
b.Locations of construction joints.
c.Placement procedures.
d.Procedures for supplemental heating of surrounding prefabricated elements.
6.Method of curing, including means and materials.
ULTRA HIGH -PERFORMANCE CONCRETE SECTION 614 265 C. Temperature Control Plan. When temperature ranges fall outside of the manufacturer’s recommended placement temperatures, submit a Temperature Control Plan in accordance with
D.Prior to the start of UHPC placement, schedule an on -site meeting with the UHPC manufacturer’s
representative, the Contractor, and the Engineer to review the approved Quality Control Plan and clearly outline the procedures for mixing, transporting, fini shing, and curing of the UHPC.
2 Surface Preparation
A.Prior to placing UHPC, pre -wet surfaces to a saturated surface dry (SSD) condition, in accordance
with the UHPC manufacturer’s recommendations. An SSD condition is defined as a concrete surface that has absorbed the maximum amount of water without pondi ng on the surface.
B.For UHPC closure pours, create an exposed aggregate, 1/4-inch amplitude finish on all concrete
surfaces that will be in contact with UHPC.
1.Achieve SSD by placing wet burlap on the surface for a minimum of 24 -hours or by other means
submitted for approval by the engineer.
2.Use compressed air, free of oil, to blow out any standing water.
3 Formwork
A.Design and fabricate formwork in accordance with Section 604.03.2 and the recommendations of
the UHPC manufacturer.
1.Construct forms from a nonabsorbent homogeneous material that is properly sealed and
capable of resisting the hydrostatic pressures from UHPC in the unhardened state.
2.Cover all UHPC closure pours with a top form with a moisture barrier.
3.Do not remove formwork until a compressive strength of 1 0-ksi is achieved.
4 Mixing
A.Mix UHPC batches in accordance with the manufacturer’s requirements.
B.Provide a minimum of two portable batching units for mixing of the UHPC. Mixing equipment
which is not supplied by the UHPC manufacturer must be reviewed by the UHPC manufacturer for adequacy.
C.A representative from the UHPC manufacturer must be present during mixing, transporting,
placing, finishing, and curing of the UHPC.
5 Placin g and Curing
A.Place and cure the UHPC in accordance with the manufacturer’s recommendations, the Quality
Control Plan, and the Temperature Control Plan.
B.Use in -place temperature monitors to monitor curing temperatures.
C.When placing UHPC closure pours:
1.Do not internally vibrate the UHPC. Rodding may be used to achieve a suitable blended
connection where two successive pours meet.
Source: Delaware Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 274–275 of 779.