8-12 Section 804. Concrete Barriers, Glare Screens, and Foundations for Light Standards and Sign Supports
804.01 Description
This work consists of co nstructing concrete barriers , glare screens, and foundations for light standards and sign supports.
804.02 Materials
Provide material in accordance with the following sections : Concrete, Grade 3000 ........................................................................ 1004 Concrete, Grade 4500 ........................................................................ 1004 Mortar and Grout, Type R -2, Type H -1 ................................................ 1005 Granular Material Class II ..................................................................... 902 Curing Compound ................................................................................. 903 Dowels and Bar Reinforcement ............................................................ 905 Anchor Bolts , Nuts and Washers .......................................................... 908 Joint Materials ....................................................................................... 914 Electrical Conduit .................................................................................. 918 Barrier Reflector Markers ...................................................................... 922
804.03 Construction
A.Preparation of Base. Prepare the base for concrete barrier in accordance with subsection 602.03.B.
B.Forming
1.Concrete Barrier and Glare Screen . Use either fixed-fo rm or slip-form methods to construct barrier and glare screen in accordance with the MDOT Standard Plan R -49 series, R-54 series, and R -76 series . Verify a smooth surface with uniform appearance. Form the top and faces of barrier and glare screen within a tolerance of ½ inch over 10 feet, based on the Engineer’s use of a 10-foot straightedge, except at grade changes and curves . Construct barrier or glare screen free of high or low areas and other irregularities . Repair minor defec ts while the concrete is plastic, using either mortar obtained by screening out the coarse aggregate from the barrier or glare screen concrete.
2.Light Standard Foundations and Sign Support Foundations . Cast in place light standard and sign support foundatio ns using fixed forms in accordance with the MDOT Standard Plan R -50 and R-51 series . The Engineer may approve casting the footings without using forms where soil conditions allow. MDOT Standard Specifications for Construction Section 804 8-13 C. Reinforcement, Anchor Bolts, and Dowels
1.Reinforcement . Place steel reinforcement in accordance with subsection 706.03.E.
2.Dowels . Install anchor dowels as required when casting barrier separately from the base. Set the dowels in the base while the concrete is plastic, or drill holes into the hardened concrete base and grout the dowels in place. Use non-shrinking grout selected from the Qualified Products List. If glare screen is cast separately from the barrier , drill holes for dowels into the hardened concrete and grout the dowels in place. Use non-shrinking grout selected from the Qualified Products List. Clean holes with a jet of compressed air, free of oil and water, with a minimum pressure of 90 psi . If using hydraulic grout, wet the interior surfaces of holes just before grouting.
3.Anchor Bolts. Position the anchor bolts for light standards and sign supports, as required, and secure with a template. Correct improper positioning of anchor bolts as directed by the Engineer before placing the concrete. Leave the template in place for at least 24 hours after placing concrete.
D.Finishing . Finish barrier and glare screen surfaces exposed to traffic with a smooth, uniform finish. Correct minor blemishes and irregularities on the barrier surface with a fine textured broom. Do not add water to the concrete surface to aid finishing.
E.Stenciling . Stencil survey station numbers into the traffic sides of the barrier in accordance with subsection 602.03.L. Do not stamp, stencil, or in any way mark concrete with a company name, logo, or other such information.
F.Curing . Cure concrete barriers , glare screens, and foundations in accordance with subsection 602.03.M. Protect the treated surface with an unbroken film for at least 5 days. If the film is damaged during curing , including rain damage, apply a new coat of material to the affected areas equal in curing value to the original coat.
G.Joints . Construct transverse joints in accordance with the p lans. If constructing the barrier on a concrete base or shoulder not separat ed by a sealed expansion joint, construct expansion joints and plane-of -weakness joints in the barrier directly over the corresponding joints in the concrete base or shoulder. MDOT Standard Specifications for Construction Section 804 8-14 H. Concrete Barrier Backfill . In split barrier sections, backfill with Class II granular material between the barrier sections and below the concrete filler slab . The Engineer may approve alternate backfill material. Place the backfill material in layers no greater than 9 inches deep a nd compact to 95% . Do not backfill cast-in-place (CIP) concrete barrier until the concrete attains 70 % of the 28-day flexural or compressive strength.
I.Weather and Temperature Limit ations . Protect the concrete in accordance with subsection 602.03.T.
J.Permanent Barrier Reflector Marker . Install barrier reflector markers on single-face, double-face, and split concrete barrier in accordance with the MDOT Standard Plan R -49 and R-54 series and subsection 711.03.F.
804.04 Measurement and Payment
Pay Item Pay Unit Conc Barrier , Single Face, Type __ ........................................................... Foot Conc Barrier , Double Face, Type __ .......................................................... Foot Conc Barrier , Split, Type __ ....................................................................... Foot Conc Barrier Backfill, CIP ................................................................ Cubic Yard Glare Screen, Conc ................................................................................... Foot Glare Screen, Conc, Split .......................................................................... Foot Light Std Fdn, Conc Barrier ...................................................................... Each Sign Support Fdn, Conc Barrier , Truss Type __ ........................................ Each
A.Concrete Acceptance. Conduct concrete QC as specified in section 1002. The Engineer will conduct QA as specified in section 1003. The Department will pay for this work based on the QA results.
B.Concrete Barrier and Glare Screen . The Engineer will measure concrete barrier and glare screen parallel to the centerline, including transition sections to vertical -faced barrier . The Engineer will measure Conc Barrier , Split and Glare Screen, Conc, Split in place, including tapered sections at each end of the structure, in accordance with MDOT Standard Plan R -49 and R-76 series . The Engineer will not deduct gaps for light standard foundations, sign support foundations, or pier columns. The Engineer will m easure glare screen end sections as full -height sections.
C.Concrete Barrier , Double Face, Type A, and Concrete Barrier , Double Face, Type B . The unit price for Conc Barrier , Double Face, Type A includes the cost of constructing Conc Barrier , Double Face, Type A using dowels and a widened base, as for Conc Barrier , Double Face, Type B as shown on the MDOT Standard Plan R -49 series. MDOT Standard Specifications for Construction Section 804 8-15 The unit price for Conc Barrier , Double Face, Type B includes the cost of required dowels. The unit price for other pay items wil l include the cost of the base for Conc Barrier , Double Face, Type B .
D.Concrete Barrier Backfill , CIP . The Engineer will measure Conc Barrier Backfill , CIP based on plan quantities in accordance with subsection
109.01 The unit price for Conc Barrier Backfill, CIP includes the cost of
backfill placed between split sections. The Engineer will measure and the Department will pay for the concrete filler slab between split sections, in accordance with subsection 803.04, as Sidewalk, Conc, 4 inch . The unit price for Sidewalk, Conc, 4 inch includes the cost of placing the fiber joint filler. The Department will not make deductions in these quantities for gaps for light standard foundations, sign support foundations, or pier columns.
E.Steel Reinforcement . The unit prices for Glare Screen, Conc and Glare Screen, Conc, Split include the cost of steel reinforcement, if required.
F.Installing Glare Screen . The unit prices for Glare Screen, Conc and Glare Screen, Conc, Split include the cost of drilling into the existi ng barrier and grouting in the steel reinforcement if a concrete glare screen is cast on top of an existing concrete barrier .
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 573–576 of 1,146.