City of Bowling Green, MO Streets

Portland cement shall conform to the current ASTM standard specification for Portland cement.

Fine aggregate.

Fine aggregate shall consist of river sand well graded coarse to fine conforming to the following gradation requirements:

	Passing ⅜ inch sieve	100 percent
	Passing No. 4 sieve	95 — 100 percent
	Passing No. 20 sieve	40 — 75 percent
	Passing No. 50 sieve	5 — 30 percent
	Passing No. 100 sieve	0 — 10 percent

Fine aggregate shall not contain deleterious substances exceeding the following limits (by weight):

Clay lumps		0.25 percent
Coal and lignite		0.25 percent
Material passing No. 200 sieve:
	Natural sand	2.00 percent
	Manufactured sand	4.00 percent
Other deleterious substances		0.10 percent

Coarse aggregate.

Coarse aggregate shall consist of river gravel or crushed stone of sound, durable, uncoated particles which meet the purity and soundness requirements of the Missouri State Highway Department Standard Specifications for Highway Construction. Stone will be used only from rock ledges accepted by the Missouri State Highway Department.

Coarse aggregate shall meet the following requirements:

	Passing 2 inch square sieve	100 percent
	Passing 1½ inch square sieve	95 — 100 percent
	Passing ¾ inch square sieve	36 — 70 percent
	Passing ⅜ inch square sieve	10 — 30 percent
	Passing No. 4 sieve	0 — 5 percent

Air entraining agent shall meet the current ASTM standard requirements.

(5)

Water used in mixing or curing concrete shall be clean and free from injurious amounts of oil, salt, acid, vegetable or other substances harmful to concrete.

Construction.

Equipment.

Equipment and tools for handling materials and performing all parts of the work must meet the approval of the City Street Superintendent as to design, capacity and mechanical conditions and must be on the job before the work is started. Equipment which is not maintained in full working order and is inadequate to obtain the results prescribed shall be improved or similar equipment substituted or added as directed by the City Street Superintendent or his/her designated representative.

Side forms may be made of steel or wood as approved by the City Street Superintendent and the height shall be equal to the thickness of the pavement at the edge, unless specifically excepted by the City Street Superintendent.

Forms shall be true to line and grade and securely staked so as to be unyielding during concreting operations. Top faces of forms shall not vary from a true plane more than one-fourth (¼) inch in ten (10) feet. Connections of form sections shall insure a tight, neat joint. Forms shall be cleaned thoroughly and oiled before concrete is placed.

Earth or subbase under forms shall be securely compacted to support forms.

Joints.

Joints shall conform to the typical details and be straight and perpendicular to the pavement surface. Transverse joints shall be at right angles to the pavement edge with a maximum spacing of twenty (20) feet. Care must be taken to avoid over finishing at joints.

Transverse and doweled construction joints shall be installed at the close of each day's work or when interruptions of more than thirty (30) minutes occur. It shall be located at least five (5) feet from any other transverse joint. It shall be formed from a clean wood plank, cut identical with the cross section of the pavement with holes drilled for dowel bars in accordance with State specifications. The plank shall be accurately set and held securely in place at right angles to the edge of the pavement. When operations are resumed, the plank shall be carefully removed and fresh concrete deposited directly against the old.

All joints, except remolded or sawed, shall be edged with a tool having a maximum radius of one-eighth (⅛) inch.

When joints are to be formed by sawing, care must be taken to saw the grooves soon after initial setting to prevent the formation of cracks due to contraction of the slab. Transverse joints shall be sawed to a depth as shown on the typical section. Any procedure for sawing joints that results in any uncontrolled cracking shall be revised immediately by adjusting the time interval between initial setting of the concrete and cutting of the joints.

(e)

Transverse joint spacing shall be adjusted to intersect the center of round structures, such as manholes, and must be more than five (5) feet away from rectangular structures at the pavement edge, such as catch basins. Catch basins and manholes shall be separated from the full depth of the pavement by expansion joint material.

(f)

All joints shall be dried, cleaned and sealed with RC-3 hot-poured asphalt before traffic is permitted on the pavement. Filling of joints shall conform to the typical details. Pouring shall be done in such a manner that material will not be spilled on the exposed surfaces of the concrete. Excess filler shall be removed immediately and the pavement surface cleaned.

(g)

When required to prevent tackiness or pickup under traffic, the exposed surface of joint filler shall be dusted with hydrated lime or sawdust. Sand will not be permitted. Other methods of preventing pickup under traffic may be used when approved by the City Street Superintendent. Poured filler shall not be placed when the air temperature in the shade is less than fifty degrees Fahrenheit (50°F), except by the approval of the City Street Superintendent.

Final surface test. The City Street Superintendent will be held responsible for the correct alignment, grade and contour specified. Any spots higher than one-fourth (¼) inch in ten (10) feet shall be ground to the required surface by the contractor at his/her expense.

Surface finish. The contractor shall provide a broomed finish surface texture.

(5)

Curing.

As soon as possible after pavement is finished and without marring the surface, the concrete shall be cured by a standard recognized method approved by the City Street Superintendent, e.g., membrane spray, wet burlap, wet earth, wet straw, watertight plastic cover, etc.

Membrane spray shall be applied by a pressure spray at a uniform rate not to exceed two hundred (200) square feet of surface area per gallon of spray.

Curing of the pavement shall be continued for not less than three (3) days after placement of the concrete.

(6)

Cold weather concreting. Except by written authorization of the City Street Superintendent, concrete placing shall cease when the descending air temperature in the shade falls below forty degrees Fahrenheit (40°F). When concreting is permitted during cold weather, the temperature of the mixed concrete shall be not less than fifty degrees Fahrenheit (50°F) nor more than one hundred degrees Fahrenheit (100°F) at the time of placing in the forms. Aggregates may be heated by steam or dry heat prior to being placed in the mixer. Water shall not be hotter than one hundred seventy degrees Fahrenheit (170°F). When concrete is being placed during cold weather and the air temperature may be expected to drop below thirty-five degrees Fahrenheit (35°F), a supply of straw or other suitable blanketing material shall be provided to cover the completed work. Care must be exercised to prevent the wind from removing same. Concrete less than twenty-four (24) hours old shall also be covered with blanketing material to prevent freezing. All blanketing shall be maintained for at least five (5) days. Concrete injured by frost action shall be removed and replaced at the contractor's expense. Concrete shall not be placed on a frozen subgrade. The use of an accelerator, such as calcium chloride, shall be used only with the consent of the City Street Superintendent.

Inspection and testing.

Slump test. Measurement of slump shall be made in conformance with the "Standard Method of Slump Test for Consistency of Portland Cement Concrete" (ASTM C 143).

Air entrainment. Concrete as placed in the forms shall contain five and one-half percent (5.5%) plus one and one-half percent (1.5%) entrained air.

Compressive strength test. Concrete used for paving shall have a minimum compressive strength of three thousand seven hundred fifty (3,750) psi at twenty-eight (28) days as determined by the "Standard Method of Test for Compressive Strength of Cylindrical Concrete Cylinders" (ASTM C 39).

Opening to traffic. The pavement shall not be opened to traffic or contractor's equipment until so ordered by the City Street Superintendent. In general, the concrete pavement shall not be opened for light traffic until the concrete is at least seventy-two (72) hours old and has attained a minimum compressive strength of three thousand (3,000) pounds per square inch. The pavement shall not be opened to all types of traffic until the concrete is at least one hundred twenty (120) hours old and has attained a minimum compressive strength of three thousand five hundred (3,500) pounds per square inch. The contractor shall maintain adequate barricades and protection of the pavement to prevent traffic from using the pavement until opened by the City Street Superintendent.

Asphaltic concrete pavement specifications.

Materials.

All materials shall conforming to the applicable requirements of the Missouri State Highway Department specifications.

Absorbent surfaces, such as water bound macadam and rolled stone bases, shall be primed with RC-70 or MC-30 liquid asphalt or SS-1 emulsified asphalt. RC-70, MC-30 or MC-70 liquid asphalt or RS-1 emulsified asphalt shall be used to prime non-absorbent surfaces such as Portland cement concrete and bituminous surfaces. The primer shall be applied in any manner satisfactory to the City Street Superintendent and at the rate per square yard within the following limits:

	Type of Surface	Minimum Gallons	Maximum Gallons
	Absorbent	0.2	0.5
	Non-absorbent	0.02	0.10

Asphaltic concrete mixture shall consist of mineral aggregates and asphalt cement combined in such proportions that the composition by weight of the finished mix shall be within the following range:

	Percent
Type C:	Min.	Max.
Passing ½ inch sieve	100	—
Passing ½ inch sieve, retained on ⅜ inch sieve	0	15
Passing ⅜ inch sieve, retained on No. 4 sieve	20	45
Passing No. 4 sieve, retained on No. 10 sieve	7	25
Passing No. 10 sieve, retained on No. 40 sieve	7	20
Passing No. 40 sieve, retained on No. 80 sieve	5	20
Passing No. 80 sieve, retained on No. 200 sieve	3	18
Passing No. 200 sieve	4	10
Asphalt cement	3.5	7

	Type X (Black Base):	By Weight
	Passing 1½ inch sieve	100
	Passing ½ inch sieve	60 — 90
	Passing No. 4 sieve	35 — 65
	Passing No. 10 sieve	25 — 45
	Passing No. 40 sieve	10 — 30
	Passing No. 200 sieve	5 — 12
	Asphalt cement	3 — 6

Construction.

Equipment.

All equipment, tools, machinery and other appliances used in handling materials and performing any part of the work shall be subject to the approval of the City Street Superintendent before the work is started and whenever found unsatisfactory shall be changed or improved as required by the City Street Superintendent. All equipment, tools and machinery must be maintained in a satisfactory working condition.

The mixing plant shall conform to the "Standard Specifications for Bituminous Mixing Plant" requirements of ASTM Designation D 995, the latest edition thereof.

Pavers shall be mechanical self-powered machines capable of spreading the mixture true to the line, grade and crown as specified.

Rollers shall include a self-powered steel wheeled roller and hand tamps. Steel wheeled rollers shall weigh not less than five (5) tons and they shall be equipped with adjustable spring scrapers fitted to the driving and steering wheels. They shall also be equipped with sprinkling systems which will uniformly moisten each wheel. Wetting devices such as coco mats shall be included when necessary. In order to obtain a smooth surface on driveway approaches or steep grades, a smaller vibrator roller shall be used in rolling as required.

Methods.

Whenever it is necessary to carry traffic over the roadway during priming operations, the prime coat for absorbent surfaces shall be applied in lanes approximately one-half (½) the width of the base at the time and shall be permitted to cure before the application is made to the remaining one-half (½) width. The prime coat for non-absorbent surfaces may be applied full width, provided the primed surface, including entrances and side roads, is blotted with sand, in such a quantity as specified by the City Street Superintendent, before it is opened to traffic. Unless sand or other blotting material is spread, the contractor shall prevent traffic from using the primed surface until it is cured. It shall be the contractor's responsibility to maintain or restore the completed primed surface in such a manner that a smooth, uniform surface will be available for the asphaltic concrete.

The mixture shall be transported from the paving plant to the work in tight vehicles with metal bottoms previously cleaned of all foreign materials. The truck beds shall be raised and the inside lubricated to prevent the mixture from adhering to the bed. An excess of lubricant will not be permitted. Each load shall be covered with canvas or other suitable material of sufficient size to protect it from the weather.

The mixture shall not be spread unless the ambient temperature is forty degrees Fahrenheit (40°F) and rising and only upon a surface which is dry and when weather conditions are suitable. The mixture shall be delivered on the job at a minimum workable temperature of two hundred fifty degrees Fahrenheit (250°F). Except as otherwise specified herein, the mixture shall be spread by means of an approved mechanical paver and finishing machine as herein specified. Mixtures shall be dumped in the center of paver hopper and care exercised to avoid overloading and spilling over of the mixture upon the subgrade or base. Pavers shall operate at such speed as may be indicated to insure a smooth riding surface and the mixture shall be delivered to the paver at such a rate as will enable the paver to be operated continuously.

The mixture shall be thoroughly and uniformly compressed by steel wheeled rollers, as soon after being spread as it will bear the weight of the roller without undue displacement. Delays in rolling freshly spread mixture will not be tolerated.

(e)

After final compression, the surface shall be smooth and true to the established crown and grade. It shall have the average thickness specified and shall at no point vary more than one-quarter (¼) inch from the specified thickness. Any low or defective places shall immediately be remedied by cutting out the course at such spots and replacing it with fresh hot mixture which shall be immediately compacted to conform with the surrounding area and shall be thoroughly bonded to it. The finished pavement shall be set free from depressions exceeding one-eighth (⅛) inch as measured with a ten (10) foot straight edge paralleling the centerline of the roadway. No traffic shall be permitted on the finished pavement until it has cooled to atmospheric temperature. After final compression, all compacted mixtures shall have a density not less than ninety-five percent (95%) of the maximum possible density of a voidless pavement composed of the same materials in like proportions. If the density of the finished base courses and surface course is less than ninety-five percent (95%), additional rolling will be required. Additional rollers, of the type and weight herein specified, shall also be furnished by the contractor if, in the opinion of the City Street Superintendent, they are necessary for property compaction.

(f)

Longitudinal and transverse joints shall be made in a careful manner. Well bonded and sealed joints are required. Joints between old and new pavements or between successive day's work shall be carefully made in such a manner as to insure thorough and continuous bond between the old and new surfaces. Hot smoothers or tampers shall be carefully employed in such a manner as to heat the old pavement sufficiently (without burning it) to insure a proper bond.

Inspection and testing.

General. All materials and work shall be subject to inspection at all times by the City Street Superintendent or his/her duly authorized representative and no materials shall be delivered or accepted nor work performed without proper authorization of the City Street Superintendent. In order to assure the use of suitable materials, the City Street Superintendent shall have the right to make any inspection he/she may deem necessary, either at the plant of the contractor or his/her supplier or on the job site. The City Street Superintendent may at any time authorize the collection of samples of materials from any source he/she may direct and subject them to tests provided for in these specifications by a testing laboratory approved by him/her for determination of their quality and fitness for work under this contract. The expense of such sampling and testing shall be borne by the City. The contractor shall afford such facilities as may be required for collecting samples.

Mixing plant inspection. The City Street Superintendent or his/her authorized representative shall have access at any time to all parts of the mixing plant in order to ensure the manufacture of the mixture in strict accordance with these specifications. In order that accurate and sufficiently large samples of aggregates may be obtained from the bins over the mixer, easy and safe access shall be provided to the location of the plant where such samples may be taken. The mixing plant operation shall conform to the applicable requirements of the Missouri State Highway Department specifications.

Determination of bitumen content. Bitumen content shall be determined in accordance with the requirements of the ASTM Designation D 1097, the latest revision thereof.