Category:302 Stabilized Permeable Base

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302.1 Construction Inspection for Sec 302

302.1.1 Description (Sec 302.1)

Treated permeable base provides a structural, highly permeable drainage layer. This work consist of furnishing and placing a stabilized permeable base material.

302.1.2 Material (Sec 302.2)

302.1.2.1 General (Sec 302.2.1)

Stabilized permeable base shall be either asphalt binder stabilized or Portland cement stabilized at the option of the contractor.

302.1.2.2 Asphalt Stabilized Permeable Base (Sec 302.2.2)

All proportioning, mixing, and transporting shall be in accordance with Sec 401.

302.1.2.3 Cement Stabilized Permeable Base (Sec 302.2.3)

All proportioning, mixing, and transporting shall be in accordance with Sec 401. Fly ash and ground granulated blast furnace slag shall not be used. Cement and water must conform to specific material requirements of Sec 1019 and Sec 1070. Water must be free from substances deleterious to hardening of cement. Water from sources approved for drinking purposes is normally satisfactory.

302.1.3 Construction Requirements (Sec 302.3)

Review the general construction requirements listed in. Many of the requirements for producing and placing treated permeable bases are also those specified for asphalt concrete, portland cement concrete, and portland cement concrete pavement. Check the appropriate specifications for applicable provision.

302.1.3.1 Contamination (Sec 302.3.1)

Contamination, filling voids with foreign material, will destroy the bases’ function. The engineer should be alert to this problem and require the contractor to take steps to ensure the base remains free of any foreign material.

302.1.3.2 Displacement (Sec 302.3.2)

Rutting effects the ability of the base to drain and results in areas of deficient thickness. Rutting or other displacement of the permeable base or the underlying base is not permitted. If displacement occurs, which could result in ponding or a non-uniform, non-draining thickness of permeable base, the material must be completely removed without disturbing the adjacent or underlying material and shall be replaced at the contractor’s expense.

302.1.3.3 Asphalt Stabilized Permeable Base (Sec 302.3.3)

Applicable sections of Sec 401 apply, except as noted herein. Observe temperature requirements and the rolling of asphalt treated bases to ensure compaction meets specifications. Ensure minimum lift thicknesses are maintained and document.

302.1.3.4 Cement Stabilized Permeable Base (Sec 302.3.4)

Cement Stabilized Permeable Base consists of base aggregate, cement, and water uniformly mixed, hauled and spread in one layer, compacted, finished, and cured in accordance with Sec 501 of Standard Specifications, and in reasonably close conformity with lines, grades, thickness, and typical cross sections shown on the plans.

Subgrade should be prepared and shaped in accordance with Sec 209 of Standard Specifications. Soft or spongy areas in subgrade should be removed, replaced with satisfactory material, and properly compacted. All drainage conduit, including underdrain if required, should be in place.

Ensure minimum lift thicknesses are maintained and documented.

302.1.4 Method of Measurement

Final measurement of the completed permeable base will not be made except for authorized changes during construction or where appreciable errors are found in the contract quantity.

302.1.5 Basis of Payment

The accepted quantities of permeable base of the thickness specified will be paid for at the contract unit price for each of the pay items included in the contract.