CONCRETE BARRIER SECTION 723 403 SECTION 723 — CONCRETE BARRIER
723.1Description.
This work consists of constructing concrete barriers.
723.2Materials.
A.Borrow, Type C Section 1001
B.Bar Reinforcement Section 1037
1.Epoxy Coated
2.Grade 60
C.Expansion Joint Material Section 1042 .3.D
D.Liquid Membrane -Forming Compounds for Curing Section 1022
E.PCC Section 1022
1.Minimum 28 -day Compressive Strength - 4,500 pounds per square inch
2.Blend of a minimum of 40 percent Ground Granulated Blast Furnace Slag (GGBFS)
3.Fine Aggregate
F.Geotextile Section 1060
G.Coarse Aggregate , No. 57 Stone Section 1004
H.Metal Screen Galvanized Steel
I.Pipe for Weep Hole , PVC Schedule 40 Section 1049
J.Silane Based Concrete Sealer Section 1045.3
k.The Department will not allow supplier changes or substitutions once the project starts without
the engineer’s approval.
723.3Construction.
A.Provide precast or cast -in place barriers meeting contract requirements. Use slip -form
construction methods in accordance with the contract. Conduct a pre -pour meeting at least 10 - days before the start of work with representatives from the Department, the contractor, and other involved parties.
B.Excavate and compact within the template of the barrier in accordance with Section 202 and the
contract. Remove unsuitable material below the proposed foundation and replace with Borrow Type C as directed by the engineer in accordance with Section 202.
C.Construct cast -in-place barrier with forms in accordance with Section 604 and contract. Place
reinforcement bars in accordance with Section 611 and contract. Construct and c ure cast -in-place barrier in accordance with Section 610.3.6.
D.Construct precast units in accordance with Section 612. Remove the precast units from the forms
and casting bed after 12 -hours if the units reach a compressive strength of at least 1,400 PSI. Saw cut joints to control cracking of concrete. CONCRETE BARRIER SECTION 723 404 E. Place weep holes at 15 -foot on center and in accordance with the contract. Place metal screen with openings no bigger than 1/2 -inch and no smaller than 3/8 -inch.
F.Apply a Class 2 rubbed finish to exposed cast -in-place or precast barrier faces in accordance with
G.Ensure that the barrier surfaces vary no more than 1/4 -inch in 10 -feet as measured from a
straightedge longitudinally. Meet a tolerance of 1/4 -inch in vertical and horizontal alignment between adjoining units measured using a 10 -foot straightedge longitudinally across the joint.
H.Construct joints in accordance with Section 6 10 and the Standard Construction Details.
I.Place and compact backfill of remaining excavated areas after placing the barrier. Compact the
material to a minimum of 95 percent of the maximum density, in accordance with Section 202.3.9.
J.Install barrier mounted delineators on the barrier side that faces traffic. Install barrier mounted
delineators as follows:
1.Place the delineator 39-inches above the final roadway surface for 42 -inch or taller barriers
when measured to the top of the delineator .
2.Place the delineator 29-inches above the final roadway surface for barriers less than 42 -inches
tall measured to the top of the delineator .
3.For tangent sections of barrier, s pace delineators horizontally 100 feet apart measured from the
center of 1 delineator to the next reflector. For barrier sections less than 200 linear feet long, evenly space a minimum of 2 delineators on the traffic face of the barrier. For barrier sections approaching and located on horizontal curves, follow the requirements of Table 3F -1 of the DE MUTCD
K.Prepare the surface ahead of sealing in accordance with Section 613.3.B.
L.Seal surface exposed concrete barrier with a silane sealer meeting the requirements of Section
1045.3 in accordance with Section 613.3.D.
723.4Method of Measurement.
The Department will measure the quantity of concrete barrier as the number of linear feet constructed , placed , and accepted. The Department will measure the length along the centerline of the concrete barrier.
723.5Basis of Payment.
A.The Department will pay the quantity of concrete barrier at the contract unit price per linear foot
constructed , placed, and accepted. Price and payment will constitute full compensation for:
1.Excavation within the template of the item;
2.removal and disposal of existing materials;
3.bedding and foundation preparation;
4.providing and placing materials and components;
5.compaction;
6.forms and forming;
7.supplying, placing, finishing, curing , and sealing PCC;
CONCRETE BARRIER SECTION 723 405 8. reinforcing steel;
9.joints; and
10.weep holes and metal screen.
B.The Department will pay for:
1.Undercut in accordance with Section 202;
2.PCC removal in accordance with Section 211;
3.saw cutting in accordance with Section 762;
4.GABC in accordance with Section 301;
5.bituminous pavement patching in accordance with Section 40 1; and
6.barrier mounted delineators in accordance with Section 824.
ITEM DESCRIPTION UNIT 72300 1 TL-3 ROADSIDE BARRIER LF 72300 2 TL-4 ROADSIDE BARRIER LF 72300 3 TL-5 ROADSIDE BARRIER LF 7230 10 TL-3 MEDIAN BARRIER LF 7230 11 TL-4 MEDIAN BARRIER LF 7230 12 TL-5 MEDIAN BARRIER LF
See Standard Construction Details for concrete barrier dimensions per Test Level (TL). IMPACT ATTENUATOR SECTION 724 406 SECTION 724 — IMPACT ATTENUATOR
724.1Description.
This work consists of providing and installing impact attenuators. Impact attenuator types are defined as follows:
A.Sacrificial – Devices designed for a single impact. These systems’ major components are destroyed
in impacts and must be replaced, but many of the other parts of the system can be reused .
B.Reusable – Contain some major components that may be able to survive most impacts intact and
can be salvaged when the unit is being repaired.
C.Low Maintenance – Devices that either suffer very little, if any damage, upon impact and are
easily pulled back into their full operating condition, or they partially rebound after an impact and may only need an inspection to ensure that no parts have been damaged, misaligned, or otherwise disabled.
724.2Materials.
A.Submit documentation requesting approval of impact attenuators 14 -days before the start of
work. Submission requirements and instructions for source information are listed on DelDOT’s website: https://deldot.gov/Business/prodlists/index.shtml .
B.Provide impact attenuators to the latest MASH compliance or in accordance with contract,
selected from the approved products list. The list can be accessed by going to (https://www.deldot.gov/Business) and looking for the Approved Products List tab on th e page.
C.Before installation, submit the choice of impact attenuator chosen for use on the project, with the
manufacturer’s installation instructions, to the engineer.
D.Provide an impact attenuator designed to leave no solid debris on the roadway after a head -on or
side angle impact. Refer to the contract for dimensional requirements, if any.
E.Impact attenuator designs:
1.Type 1 – Test Level 2 – Sacrificial
2.Type 2 – Test Level 2 – Reusable
3.Type 3 – Test Level 2 – Low Maintenance
4.Type 4 – Test Level 3 – Sacrificial
5.Type 5 – Test Level 3 – Reusable
6.Type 6 – Test Level 3 – Low Maintenance
724.3Construction.
A.Provide shop drawings to the engineer for approval before beginning installation. Assemble and
install the impact attenuator in accordance with the manufacturer’s requirements. Grade the area between the edge of pavement and the back of the impact attenuator in accordance with the manufacturer’s requiremen ts.
B.Construct guardrail end treatment using applicable construction methods provided in Section
720.3.
Source: Delaware Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 413–416 of 779.