302Blended Base and Blended Subbase

Blended Base and Blended Subbase

302.1DESCRIPTION

1 This section describes the requirements for furnishing and placing blended base or blended subbase on a prepared surface.

302.2MATERIALS

1 Provide materials in accordance with the following:

Material Subsection Aggregate 803

2 Reclaimed Asphalt Pavement (RAP)–Existing asphalt pavement milled from the roadway within the project limits.

3 Reclaimed Portland Cement Concrete Pavement (RPCCP)–Existing concrete pavement removed from the roadway within the project limits.

302.3EQUIPMENT

1 Unless otherwise approved by the engineer, use a pugmill capable of thorough and consistent blending to mix aggregate, RAP, RPCCP, and water for blended bases and subbases.

302.4CONSTRUCTION

302.4.1 General

1 Remove the existing plant mix pavement, concrete pavement, or both from the roadway; haul it to the plant site; and stockpile it in accordance with Subsection 202.4.5, Removal of Surfacing, Concrete, Sidewalks, Curbs, Gutters, Median, Double Gutter, Etc. Minimize contamination of the milled asphalt pavement or removed concrete pavement. If required, crush the RAP/RPCCP to the maximum size specified, and stockpile it separately.

2 Before blending the virgin crushed base aggregate with RAP/RPCCP, obtain virgin crushed base aggregate samples at the direction of the engineer in accordance with the Materials Testing Manual. Sample the virgin crushed base aggregate from the belt immediately before blending it with RAP/RPCCP. 3 Mix the RAP/RPCCP, virgin crushed base aggregate, and water.

Blended Base and Blended Subbase SECTION 302

4 Haul, place, and compact the blended base or blended subbase in accordance with Subsection 301.4.2.3, Placing.

302.4.1.2 Lot and Sublot Sizes

1 A lot for gradation is defined as the quantity represented by five tests or a maximum of 5000 ton [5000 t] of virgin crushed base, and a sublot is the quantity represented by one test or a maximum of 1000 ton [1000 t] of virgin crushed base aggregate. The sublot size will be dependent on the rate of virgin crushed base aggregate to be incorporated into the blended base or blended subbase using the equation below.

LS = 5000 (V𝑢𝑢/100)

SS = LSBB

where:

LS = Lot Size for Blended Base or Blended Subbase (ton) [t]

SS = Sublot Size for Blended Base or Blended Subbase Evaluated (ton) [t]

V U= Percent Virgin Crushed Base (%)

302.5MEASUREMENT and PAYMENT

302.5.1 General

1 The engineer will measure Blended Base and Blended Subbase by the ton [metric ton], cubic yard [cubic meter], or square yard [square meter].

neat line for width, including one half the taper width where applicable, multiplied by the neat line for thickness, multiplied by the neat line for length of the completed surface.

width, including one half the taper width where applicable, multiplied by the neat line for length of the completed surface.

mixing, added to the material before the material is weighed, will not be deducted from the measurement unless it exceeds the maximum moisture content.

Blended Base and Blended Subbase SECTION 302

2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest Blended Base SY, CY, TON [m2, m3, t] 0.1 ft, 0.1 ft, 0.05 t [0.5 m, 0.5 m, 0.05 t] SY, CY, 0.05 ton [m2, m3, t] Blended Subbase SY, CY, TON [m2, m3, t] 0.1 ft, 0.1 ft, 0.05 t [0.5 m, 0.5 m, 0.05 t] SY, CY, 0.05 ton [m2, m3, t]

302.5.2 Referenced Sections for Direct Payment

1 When specified, the engineer will measure and pay for:

302.5.3 Determination of Pay Factor

1 The engineer will evaluate aggregate gradation tests for virgin crushed base in accordance with Subsection 1 13.1, Acceptance of Aggregate, and will apply pay adjustments. The maximum pay factor per lot will be 1.00.

302.5.4 Pay Adjustments

1 The engineer will calculate pay adjustments for blended base and blended subbase as follows:

BBPA = BB x (CBPF - 1) x LS x (VU / 100)

where:

BBPA = Pay Adjustment for Blended Base or Blended Subbase for evaluated lot ($$)

BB = Unit Contract Price for the Blended Base or Blended Subbase pay item ($$)

CBPF = Crushed Base pay factor

Blended Base and Blended Subbase SECTION 302

LS = Lot size for Blended Base or Blended Subbase pay item (ton [t], CY [m3])

VU = Percent virgin crushed base