116425 — Lightweight Superstructure Concrete

425.01 Description

Furnish and install lightweight concrete.

425.02 Materials

Lightweight Concrete 902.10, Mix 10

425.03 Construction

Conform to 420.03 and as specified herein. Handle lightweight aggregates in a manner that provides a thorough sprinkling of the aggregates during the stockpiling to produce damp aggregate. Sprinkle to obtain uniform distribution of moisture. Then permit the aggregates to drain as long as necessary to produce a uniform moisture content. Maintain the moisture content as much as practical until the aggregate is used. Add the admixtures to the mix according to the manufacturer’s recommendations.

425.03.01 Existing Structures. Remove existing bridge decks as specified in 405.03.02. Note

that the deck replacement material may be lighter than the existing deck and the deflection caused by the lighter material will be less than the material removed. Therefore, compute modified rebound figures to be used in lieu of dead load deflections to establish grade controls to produce finished tops of concrete bridge decks that will be true to as planned line and grade.

425.04 Measurement and Payment

Lightweight concrete structures will be measured and paid for as specified. The payment will be full compensation for all forms and form removal, reinforcing steel, curing and misting, scuppers, mechanical and electrical work, all cost incidental to the conducting of tests for oxygen content and presence of gases and applying mechanical ventilation to confined spaces, year built markings, and for all material, labor, equipment (including safety equipment), tools, and incidentals necessary to complete the work. 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS The construction of drainage and weep holes, any pipe necessary, expansion material, flashing, dampproofing, membrane waterproofing, epoxy bonding compound, joints and their placement will not be measured but the cost will be incidental to the lightweight concrete item. No deduction in lightweight concrete quantities will be made for pipes or conduits having diameters less than 8 in., reinforcing steel, anchors, or any other appurtenances.

425.04.01 Lightweight Superstructure Concrete will not be measured but will be paid for at the

Contract lump sum price unless otherwise specified. 425.04.02 Lightweight concrete parapets and median barriers will not be measured but will be paid for at the Contract lump sum price for the pertinent Lightweight Concrete Parapet or Lightweight Concrete Median Barrier items.

425.04.03 Floodlighting will be measured and paid for as specified in 420.04.06.

425.04.04 Linseed Oil Protective Coating will be measured and paid for as specified in 420.04.07.

426 — LATEX MODIFIED CONCRETE OVERLAY FOR BRIDGE DECKS CATEGORY 400 STRUCTURES SECTION 426 — LATEX MODIFIED CONCRETE OVERLAY FOR BRIDGE DECKS

426.01 Description

Remove the specified amount of the existing bridge deck material mechanically and through hydro-demolition, remove additional areas of deteriorated concrete as directed by the Engineer, clean surface areas to be overlaid. Clean scuppers, downspouts and joint troughs, replace deteriorated reinforcing steel, and place latex modified concrete (LMC). Restrictions. Do not place LMC in Allegany, Garrett, and Washington counties between November 1 and April 30. In all other Counties, do not place LMC between December 1 and April 30. Do not remove any portion of existing bridge deck that will not be overlaid and cured per these restrictions.

426.02 Materials

Fine Aggregate 901.01 Coarse Aggregate 901.01, Size No. 7 Portland Cement Type I 902.03 Concrete for Patching 902.10 Latex Modified Concrete 902.13 Reinforcement Section 908 Water 921.01

426.03 Construction

Dispose of removed material at an approved spoil area.

426.03.01 Collection and Containment of Effluent. Collect and contain all liquid and/or solid

effluent from the high pressure water jet method of concrete removal and ensure that no such effluent reaches any traveled roadway, waterway, or other drainage facilities. The effluent shall be disposed at a site with an MDE approved industrial discharge permit appropriate for the effluent collected. Failure to collect and contain all liquid and/or solid effluent from the high pressure water jet concrete removal will be cause for immediate shut down of high pressure water jet concrete removal operations until corrective actions are taken. Any additional costs associated with a failure to collect and contain the effluent shall be at no additional cost to the Administration 2025 STANDARD SPECIFICATIONS FOR CONSTRUCTION AND MATERIALS