306.01 238 SECTION 306 – PORTLAND CEMENT CONCRETE BASE
306.01 Description ................................ ................................ ................... 238
306.02 Materials ................................ ................................ ...................... 238
306.03 Equipm ent ................................ ................................ .................... 239
306.04 Proportioning ................................ ................................ ............... 239
306.05 General ................................ ................................ ......................... 239
306.06 Surface Finish and Tolerances ................................ ..................... 239
306.07 Integral Curb ................................ ................................ ................ 239
306.08 Tolerance in Base Thickness ................................ ........................ 240
306.09 Method of Measurement ................................ .............................. 240
306.10 Basis of Payment ................................ ................................ .......... 240
DESCRIPTION
306.01 Description
This work consists of constructing a single course of Portland Cement Concrete Base, with or without reinforcement, as s pecified, on a prepared surface. MATERIALS
306.02 Materials
Provide materials as specified in: Portland Cement, Type I ................................ ........................ 901.01 Fine Aggregate ................................ ................................ ............................... 903.01 Coarse Aggregate ................................ ................................ ... 903.03 Concrete Reinforcement ................................ ............................. 907 Curing Materials ................................ ................................ ......... 913 Water ................................ ................................ ...................... 921.01 Air Entraining Admixtures ................................ ............. 921.06.A.2 Chemical Admixtures and Additives ................................ ..... 921.06 306.03 239 EQUIPMENT
306.03 Equipment
Provide equipment as specified in 501.04. CONSTRUCTION REQUIREMENT S
306.04 Proportioning
Proportion materials for concrete base as specified in 501.03.A.
306.05 General
Prepare the subgrade as specified in 205, 207, or 302, whichever is applicable. Perform sub -base or subgrade treatment, when specified, according to the applicable Sections of Part 3 of these Specifications. To construct cement concrete base, apply the applicable methods and procedures specified in 501.07, 501.10, 501.12 through 501.15, 501.16.A through 501.16.F, 501.17 through 501.24, and 604.11 through 604.13 .
306.06 Surface Finish and Tolerances
Slightly roughen the surface of the concrete base by brooming. Meet the surface tolerances specified in 501.17.
306.07 Integral Curb
Construct edging (integral curb), when shown on the Plans or required by the Engineer, of the same concrete mixture as is used in the base. Construct edging to the width and height shown on the typical cross -section by securely fastening auxiliary forms to the regular side forms of the base. Except as otherwise directed by the Engineer, construct edging immediately after the final floating of the base and before the concrete in the base upon which the edging is to be constructed has taken its initial set. Roughen the surface of the base before placing edging material upon it. At the end of the day’s work, the Contractor may temporarily omit the curb from a sect ion of the base sufficient in length to provide for backing -up of the paving train the following day, provided the base upon which the curb is to be placed is roughened sufficiently to bond the curb to the base. Remove all laitance from this section for t he full width of the curbs by wire brushes or other satisfactory 306.08 240 means. Ensure that the concrete placed in the edging is well consolidated to avoid honeycombing. The top of the edging shall be smooth and uniform and given a wood float finish. Shape the inside and outside edges with edging tools as shown on the Plans. For final finishing of the edging, wipe the surface with a soft brush having a width not less than the width of the edging.
306.08 Tolerance in Base Thickness
For base thickness, meet the tolerance specified for pavement thickness in 501.24. COMPENSATION
306.09 Method of Measurement
The Department will measure Portland Cement Concrete Base (Plain) and Portland Cement Concrete Base (Reinforced) of the various thicknesses specified by the square yard in accordance with 109. If during construction the Engin eer orders the cement increased or decreased from that approved for the job mix by more than 8 pounds per cubic yard, the Department will calculate the quantity of increased or decreased cement in accordance with 501.25. These c alculations will provide the basis for payment to the Contractor for additional cement, or for reimbursement to the Department for reduction in cement, as applicable.
306.10 Basis of Payment
A.General The Department will pay for accepted quantities at the c ontract prices as follows: Item Pay Unit Portland Cement Concrete Base (Plain) ___" Square Yard Portland Cement Concrete Base (Reinforced) ___" Square Yard Such payment is full compensation for furnishing and placing all materials, including edging when sp ecified, and for providing reinforcing, dowels, and joint materials. 306.10 241 The Department will pay for additional cement required if the cement is increased by more than 8 pounds per cubic yard at the purchase price,
F.O.B. the unloading point, as verified by in voices, and will provide no additional compensation for further handling. If the cement is decreased by more than 8 pounds per cubic yard, the Department will be reimbursed from any monies due the Contractor an amount equal to the purchase price of the cem ent, F.O.B. the unloading point, and no other charges will be included. The Department will not pay for any changes in the proportions of the aggregates. The Department will not make additional payment for concrete slab placed in excess of Plan thickness . The Department will not pay for any concrete base removed by order of the Engineer for deficiency in thickness or for otherwise not meeting Specification requirements. The Department will pay for work required to prepare the subgrade or sub-base in acco rdance with 306.05.
B.Thickness Adjustments Where the average thickness of base is deficient in thickness by more than 1/4 inch, but not more than 1 inch, the Department will pay an adjusted price as specified in the Table 306.10-1. Table 306.10-1: Concrete Base Deficiency Deficiency in Thickness as Determined by Cores (inches) Proportion of Concrete Price Allowed ¼ 100% > ¼ through ½ 75% > ½ through ¾ 60% > ¾ through 1 50% Where the thickness of base is deficient by more than 1 inch and, in the Engineer’s judgment, the area of such deficiency should not be removed and replaced, the Department will not make payment for the area retained. 307.01 242 SECTION 307 – BITUMINOUS PLANT MIX BASE (HOT MIX)
307.01 Description ................................ ................................ ................... 242
307.02 Materials ................................ ................................ ...................... 242
307.03 Composition of Mixtures ................................ ............................. 243
307.04 Equipment ................................ ................................ .................... 249
307.05 General ................................ ................................ ......................... 249
307.06 Preparing the Subgrade, Sub -base, or Surface ............................. 249
307.07 Thickness and Surface Requirement ................................ ............ 250
307.08 Method of Measurement ................................ .............................. 250
307.09 Basis of Payment ................................ ................................ .......... 250
DESCRIPTION
307.01 Description
This work consists of constructing one or more base course layers of aggregate and asphalt, prepared in a hot bituminous mixing plant and spread and compacted on a prepared subgrade, granular sub -base, or base. MATERIALS
307.02 Materials
Provide materials as specified in: Aggregate for Mixture, Grading A, ACRL, AS, B, BM, BM2, C, CS, or CW ..... 903.06 Asphalt Cement, Grade PG 64-22, 70-22, 76-22, 82-22 ........ 904.01 Bituminous Additives ................................ ........................ 921.06.B The specific grading of aggregate to be used will be specified in the Contract or shown on the Plans. The Engineer will accept mineral ag gregate, bituminous material, and the plant mix in accordance with 407.02.
Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 247–250 of 1,072.