Sources Sought 01 Mar 2022.pdf

Controlled unclassified information

DEPARTMENT OF THE AIR FORCE

48TH FIGHTER WING (USAFE)

SOURCES SOUGHT

48th CONTRACTING SQUADRON (USAFE)

Issue Date: 1 March 2022

Response Due Date: 8 March 2022 @ 1630 GMT

NAICS Code: 423320– Base Course, Concrete, Asphalt

Subject: Request for Information (RFI) – Base Course, Concrete, Asphalt

& Tack Coat

Description:

The 48th Contracting Squadron at Royal Air Force (RAF) Lakenheath, United Kingdom, seeks feedback from companies/entities capable of providing Base Course, Concrete, and Hot-

Mix Asphalt & Tack Coat.

Background: The 48th Contracting Squadron at RAF Lakenheath has identified a potential need for a contractor to provide Base Course, Concrete, and Asphalt & Tack Coat. The location of Base Course, Concrete, and Asphalt & Tack Coat will be delivered to RAF

Feltwell, United Kingdom.

Salient characteristics of base course:

1. Definitions: Graded-Crushed Aggregate Base Course: Graded-crushed aggregate (GCA) base course is well graded, crushed, durable aggregate uniformly moistened and mechanically stabilized by compaction. GCA has more stringent requirements and it produces a base course with higher strength and stability.

1.1. Submittals: Submit the sampling and testing reports.

1.2. Quality Assurance: Sampling and testing are the responsibility of the Contractor and performed by a testing laboratory. Test the materials to establish compliance with the specified requirements. Furnish copies of test results to the Contracting

Officer within 24 hours of completion of the tests.

1.2.1. Sampling: Take samples for laboratory testing in conformance with

ASTM D 75/D 75M or equivalent British standard approved by the CO.

When deemed necessary, the sampling will be observed by the COR.

1.2.2. Tests: Perform the following tests in conformance with the applicable standards listed.

1.2.3. Sieve Analysis: Make sieve analysis in conformance with ASTM C

117 and ASTM C 136 or equivalent British standard approved by the CO.

Sieves shall conform to ASTM E 11 or equivalent British standard approved by the CO.

1.2.4. Liquid Limit and Plasticity Index: Determine liquid limit and plasticity index in accordance with ASTM D 4318 or equivalent British standard approved by the CO.

1.2.5. Moisture-Density Determinations: Determine the laboratory maximum dry density and optimum moisture content in accordance with

ASTM D 1557 or equivalent British standard approved by the CO.

1.2.6. Wear Test: Perform wear tests on GCA course material in conformance with ASTM C 131 or equivalent British standard approved by the CO.

1.2.7. Soundness: Perform soundness tests on GCA in accordance with ASTM C 88 or equivalent British standard approved by the CO.

1.2.8. Testing Frequency

1.2.8.1. Initial Tests: Perform one of each of the following tests, on the proposed material prior to delivery, to demonstrate that the proposed material meets all specified requirements when furnished. If materials from more than one source are going to be utilized, this testing shall be completed for each source.

1.2.8.1.1. Sieve Analysis.

1.2.8.1.2. Liquid limit and plasticity index

1.2.8.1.3. Moisture-density relationship.

1.2.8.1.4. Wear.

1.2.8.1.5. Soundness.

2. PRODUCTS

2.1. Aggregates: Provide GCA consisting of clean, sound, durable particles of crushed stone, crushed gravel, angular sand, or other approved material. GCA shall be free of silt and clay as defined by ASTM D 2487 or equivalent British standard approved by the CO, organic matter, and other objectionable materials or coatings. The portion retained on the No. 4 sieve is known as coarse aggregate; that portion passing the No. 4 sieve is known as fine aggregate.

2.1.1. Coarse Aggregate: Provide coarse aggregates with angular particles of uniform density. When the coarse aggregate is supplied from more than one source, aggregate from each source shall meet the specified requirements and shall be stockpiled separately.

2.1.1.1. Crushed Gravel: Crushed gravel shall be manufactured by crushing gravels, and shall meet all the requirements specified below.

2.1.1.2. Crushed Stone: Provide crushed stone consisting of freshly mined quarry rock, meeting all the requirements specified below.

2.1.1.3. Graded-Crushed Aggregate Base Course: GCA coarse aggregate shall not show more than 40 percent loss when subjected to the Los

Angeles abrasion test in accordance with ASTM C 131 or equivalent British standard approved by the CO. GCA coarse aggregate shall not exhibit a loss greater than 18 percent weighted average, at five cycles, when tested for soundness in magnesium sulfate, or 12 percent weighted average, at five cycles, when tested in sodium sulfate in accordance with ASTM C 88 or equivalent British standard approved by the CO. The amount of flat and elongated particles shall not exceed 20 percent for the fraction retained on the 12.5 mm (1/2 inch) sieve or 20 percent for the fraction passing the 12.5 mm (1/2 inch) sieve. A flat particle is one having a ratio of width to thickness greater than 3; an elongated particle is one having a ratio of length to width greater than 3. In the portion retained on each sieve specified, the crushed aggregate shall contain at least 90 percent by weight of crushed pieces having two or more freshly fractured faces determined in accordance with ASTM D 5821 or equivalent British standard approved by the CO. When two fractures are contiguous, the angle between planes of the fractures must be at least 30 degrees in order to count as two fractured faces. Crushed gravel shall be manufactured from gravel particles 90 percent of which by weight are retained on the maximum size sieve listed in TABLE 1.

2.1.2. Fine Aggregate: Fine aggregates shall be angular particles of uniform density. When the fine aggregate is supplied from more than one source, aggregate from each source shall meet the specified requirements.

2.1.2.1. Graded-Crushed Aggregate Base Course: Provide GCA fine aggregate consisting of angular particles produced by crushing stone, or gravel that meets the requirements for wear and soundness specified for

GCA coarse aggregate. Fine aggregate shall be produced by crushing only particles larger than No. 4 sieve in size. The fine aggregate shall contain at least 90 percent by weight of particles having two or more freshly fractured faces in the portion passing the No. 4 sieve and retained on the No. 10 sieve, and 10 percent in the portion passing the No. 10 sieve and retained on the No. 40 sieve.

2.1.3. Gradation Requirements: Apply the specified gradation requirements to the completed base course. The aggregates shall be continuously well graded within the limits specified in TABLE 1, No. 2. Sieves shall conform to ASTM E 11 or equivalent British standard approved by the CO.

TABLE 1. GRADATION OF AGGREGATES

Percentage by Weight Passing Square-Mesh Sieve

Designation No. 2

50 mm (2 inch)

37.5 mm (1.5 inch) 100

25 mm (1 inch) 60-100

12.5 mm (1/2 inch) 30-65

No. 4 20-50

No. 10 15-40

No. 40 5-25

No. 200 0-8

NOTE 1: The values are based on aggregates of uniform specific gravity. If materials from different sources are used for the coarse and fine aggregates, they shall be tested in accordance with ASTM C 127 and ASTM C 128 or equivalent British standard approved by the CO to determine their specific gravities. If the specific gravities vary by more than 10 percent, the percentages passing the various sieves shall be corrected as directed by the

Contracting Officer.

1.1. Liquid limit and plasticity index: Apply liquid limit and plasticity index requirements to the completed course and to any component that is blended to meet the required gradation. The portion of any component or of the completed course passing the No. 40 sieve shall be either non-plastic or have a liquid limit not greater than 25 and a plasticity index not greater than 5.

2. EXECUTION

2.1. Stockpiling material: Stockpile all materials in the manner and at the locations designated on the attached staging plan where base coarse stockpiles are annotated. Materials obtained from different sources shall be stockpiled separately.

2.2. Disposal of unsatisfactory material: Any unsuitable materials that must be removed shall be disposed of outside the limits of Government-controlled land. No additional payments will be made for materials that must be replaced.

Salient characteristics of concrete:

1. Cementitious materials shall be Portland cement conforming to ASTM C150/C150M Type

I or equivalent British standard approved by the CO. Type I, ordinary portland cement, shall conform to ASTM C 150 or equivalent British standard approved by the CO.

1.1. Blended cement shall conform to ASTM C 595 or equivalent British standard approved by the CO, Standard Specification for Blended Hydraulic Cements, Type IP, including the optional requirement for mortar expansion and sulfate soundness. The percentage and type of mineral admixture used in the blend shall not change from that submitted for the aggregate evaluation and mixture proportioning.

1.1.1. Ground granulated blast-furnace (GGBF) slag shall conform to ASTM C 989 or equivalent British standard approved by the CO, Standard Specification for

Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars, Grade

100 or Grade 120.

1.1.2. Class F fly ash shall conform to ASTM C 618 or equivalent British standard approved by the CO, Standard Specification for Coal Fly Ash and Raw or

Calcined Natural Pozzolan for Use in Concrete, Class F, including the optional requirements for uniformity and effectiveness in controlling alkali-silica reaction, and shall have a loss on ignition not exceeding 6%. Class F fly ash for use in mitigating alkali-silica reactivity shall have a calcium oxide (CaO) content of less than 13 percent and a total equivalent alkali content less than 3 percent.

1.1.3. Silica fume shall conform to ASTM C 1240 or equivalent British standard approved by the CO, Standard Specification for Silica Fume Used in

Cementitious Mixtures, including the optional limits on reactivity with cement alkalis. Silica fume may be furnished as a dry, densified material, or as a slurry.

Provide at the Contractor's expense the services of a manufacturer's technical representative, experienced in mixing, proportioning, placement procedures, and curing of concrete containing silica fume. This representative must be present on the project prior to and during at least the first 4 days of concrete production and placement using silica fume.

1.1.4. Water for mixing and curing shall be fresh, clean, potable, and free of injurious amounts of oil, acid, salt, or alkali, except that non-potable water, or water from concrete production operations, may be used if it meets the requirements of

ASTM C1602/C1602M or equivalent British standard approved by the CO.

1.1.5. The Contractor shall seek approval from the CO prior to using any admixtures in the concrete mix. At least 30 days before the material is used, the Contractor shall submit certified copies of test results from a 3rd party laboratory for the specific lots or batches to be used on the project. Test results shall be not more than 6 months old prior to use in the work. Chemical admixtures that have been in storage at the project site for longer than 6 months or that have been subjected to freezing will be retested at the expense of the Contractor and will be rejected if test results are not satisfactory.

1.1.5.1. Air-entraining admixture shall conform to ASTM C 260 or equivalent

British standard approved by the CO, Standard Specification for Air-

Entraining Admixtures for Concrete. Calcium chloride and admixtures containing calcium chloride shall not be used. Any water-reducing or retarding admixture shall meet the requirements of ASTM C 494/C 494M or equivalent British standard approved by the CO. Type F and G high range water-reducing admixtures are not allowed.

1.2. Aggregates.

1.2.1. Aggregates shall consist of crushed stone, crushed gravel, crushed slag, screenings, natural sand, and mineral filler, as required. The portion of material retained on the 4.75 mm (No.

4) sieve is coarse aggregate. The portion of material passing the 4.75 mm (No.4) sieve and retained on the 0.075 mm (No. 200) sieve is fine aggregate. The portion passing the 0.075 mm (No. 200) sieve is defined as mineral filler. All aggregate test results and samples shall be submitted to the CO at least 7 days prior to delivery; deviations from this schedule shall be coordinated with the CO.

Aggregate testing shall have been performed within 90 days of material delivery.

1.2.2. Aggregates shall consist of clean, hard, uncoated particles meeting the requirements of ASTM C 33 or equivalent British standard approved by the

CO, Standard Specification for Concrete Aggregates, including the ASTM C

33 requirements regarding deleterious materials, abrasion loss, and soundness, and other requirements specified herein.

1.2.2.1. In addition to the grading requirements specified for coarse aggregate and for fine aggregate, the following are more requirements for combined aggregate grading:

1.2.2.2. If necessary, use a blending aggregate to meet the required combined grading. Batch this blending aggregate separately. Compute the combined grading of all aggregates used, in the proportions selected, on the basis of cumulative percent retained on each sieve specified for fine and coarse aggregate.

1.2.2.3. The materials selected and the proportions used shall be such that when the coarseness factor (CF) and the workability factor (WF) are plotted on a diagram as described in paragraph 510.2.2.1.4, the point thus determined shall fall within the parallelogram described therein.

1.2.2.4. CF is determined from the equation below. WF is defined as the cumulative percent passing the 2.36 mm (No. 8) sieve; however, adjust

WF upwards only, by

2.5 percentage points for each 42 kg/m3 (94 lbs/yd3) of cementitious material greater than 335 kg/m3 (564 lbs/yd3).

𝐶𝐹= (𝑐𝑢𝑚𝑢𝑙𝑎𝑡𝑖𝑣𝑒 𝑝𝑒𝑟𝑐𝑒𝑛𝑡 𝑟𝑒𝑡𝑎𝑖𝑛𝑒𝑑 𝑜𝑛 𝑡ℎ𝑒 9.5 𝑚𝑚 (0.375 𝑖𝑛) 𝑠𝑖𝑒𝑣𝑒)∗100

(𝑐𝑢𝑚𝑢𝑙𝑎𝑡𝑖𝑣𝑒 𝑝𝑒𝑟𝑐𝑒𝑛𝑡 𝑟𝑒𝑡𝑎𝑖𝑛𝑒𝑑 𝑜𝑛 𝑡ℎ𝑒 2.36 𝑚𝑚 (𝑁𝑜.8) 𝑠𝑖𝑒𝑣𝑒)

1.2.2.5. Plot a diagram using a rectangular scale with WF on the Y-axis with units from 20(bottom) to 45 (top), and with CF on the X-axis with units from 80 (left side) to 30 (right side). On this diagram, plot a parallelogram with corners at these coordinates: (CF-75, WF-28), (CF-75, WF-40), (CF-45, WF-32.5), and (CF-45, WF-41). If the point

1.2.2.6. determined by the intersection of the computed CF and WF does not fall within the above parallelogram, change as necessary the grading of each size of aggregate used and the proportions selected.

1.2.2.7. Plot the individual percent retained on each sieve for the combined aggregate grading, on either rectangular or semi-log graph paper. The graph shall show a relatively smooth transition between coarse and fine aggregate and shall have no major valleys or peaks in the area smaller than the 2.36 mm (No. 8) sieve. If the plot does not meet these criteria, change as necessary the grading of each size aggregate used and the proportions selected.

1.3. Coarse Aggregates.

1.3.1.1. Coarse aggregate shall consist of crushed gravel, crushed stone, or a combination thereof. The nominal maximum size of the coarse aggregate shall be no more than

37.5 mm (1.5 in). In general, the maximum size of the coarse aggregate shall be such that no areas are too small for a mixture of stone and cement to reside in the finished PCC product. When the nominal maximum size is greater than

25 millimeters [1 inch], the aggregates shall be furnished in two ASTM C 33 size groups, No. 67 and No. 4. The amount of deleterious material in each size of coarse aggregate shall not exceed the limits shown in ASTM C 33 Class

1N, 4M, or 4S, depending on the weathering region, and these limits:

1.3.1.1.1. Lightweight particles: one percent maximum by mass (ASTM

C 123, Standard Test Method for Lightweight Particles in

Aggregate).

1.3.1.1.2. Other soft particles: two percent maximum by mass (U.S. Army

Corps of Engineers (USACE) CRD-C 130, Standard

Recommended Practice for Estimating Scratch Hardness of Coarse

Aggregate Particles).

1.3.1.1.3. Total of all deleterious particles: five percent maximum by mass

(substances listed in ASTM C 33 and paragraphs 3.8.3.1.1 and

3.8.3.1.2, exclusive of material finer than a 0.075 mm (No. 200) sieve).

1.3.1.1.4. The separation medium for lightweight particles shall have a density of 2 mg/m3 (specific gravity of 2.0).

1.3.2. Fine Aggregate

1.3.2.1. Fine aggregate shall consist of natural sand, manufactured sand, or a combination of the two, and shall be composed of clean, hard, durable particles meeting the requirements of ASTM C 33 or equivalent British standard approved by the CO and the requirements herein. The amount of deleterious material in the fine aggregate shall not exceed the limits in ASTM

C 33 or equivalent British standard approved by the CO, and shall not exceed these limits:

1.3.2.1.1. Lightweight particles (ASTM C 123): 0.5 percent maximum by mass using a medium with a density of 2 mg/m3 (specific gravity of 2.0).

1.3.2.1.2. The total of all deleterious material types, listed in ASTM C 33 or equivalent British standard approved by the CO and paragraphs

3.8.4.1 and 3.8.4.1.1, shall not exceed 3 percent of the mass of the fine aggregate.

1.3.2.1.3. Fine and coarse aggregates to be used in all concrete shall be evaluated and tested for alkali-aggregate reactivity. Both coarse aggregate size groups shall be tested if from different sources.

1.3.2.2. The fine and coarse aggregates shall be evaluated separately, using

ASTM C 1260 or equivalent British standard approved by the CO, Standard Test Method for Potential Alkali Reactivity of Aggregates

(Mortar-Bar Method). The test results of the individual aggregates shall have a measured expansion equal to or less than 0.08 percent after 28 days of immersion in a 1N NaOH solution. Should the test data indicate an expansion of greater than 0.08 percent, the aggregate(s) shall be rejected or additional testing shall be performed using ASTM C 1567 or equivalent British standard approved by the CO, Standard Test Method for Determining the Potential Alkali- Silica Reactivity of Combinations of

Cementitious Materials and Aggregate (Accelerated Mortar-Bar Method), as follows: use the Contractor's proposed low- alkali portland cement

[blended cement] and SCM in combination with the proposed aggregate for the test proportioning. Determine the quantity that will meet all the requirements of these specifications and that will lower the expansion equal to or less than 0.08 percent after 28 days of immersion in a 1N

NaOH solution.

1.3.3. If none of the above options lower the expansion to less than 0.08 percent after 28 days of immersion in a 1N NaOH solution, the aggregate(s) shall be rejected and the Contractor shall submit new aggregate sources for retesting. The results of testing shall be submitted to the Contracting Officer for evaluation and acceptance.

1.4. The Contractor furnished mix design shall have a specified compressive strength (f'c) of

40.0 MPa (5801 PSI) at 28 days and a minimum of 4.0 MPa (580 psi) flexural strength at 28 days. If approved by the CO, the concrete may be air-entrained; if air entrainment is used, the air content shall be six percent with an allowable deviation of one percent. The maximum allowable water-cementitious material ratio is 0.45. The water-cementitious material ratio is based on absolute volume equivalency, where the ratio is determined using the weight of cement for a cement-only mix, or using the total volume of cement plus pozzolan converted to an equivalent weight of cement by the absolute volume equivalency method described in American Concrete

Institute (ACI) 211.1, Standard Practice for Selecting Proportions for

Normal, Heavyweight and Mass Concrete. The concrete slump shall be between 75 mm (3 in) and 127 mm (5 in).

2. Execution

2.1. ASTM C94/C94M or equivalent British standard approved by the CO, except as modified herein. Begin mixing within 30 minutes after cement has been added to aggregates. When the air temperature is greater than 29.4 degrees C 85 degrees F, place concrete within 60 minutes. With the approval of the Contracting Officer, a hydration stabilizer admixture meeting the requirements of ASTM C494/C494M Type

D or equivalent British standard approved by the CO, may be used to extend the placement time to 90 minutes.

2.2. Transporting equipment shall be in conformance with ASTM C 94/C 94M or equivalent British standard approved by the CO, and as specified herein. Concrete shall be transported to the job site in clean concrete trucks. At no point shall concrete be poured from a vertical drop of more than 1.5 m (5 ft); concrete shall be poured in continuous manner that minimizes segregation of the mix. All concrete shall be poured at the direction of the COR.

2.3. The Contractor shall coordinate all deliveries with the COR. Delays during a concrete pour that were the result of Contractor action or inaction that result in cold joints shall be removed and replaced at the Contractor’s expense.

2.4. The Contractor shall be able to deliver a minimum of 10 CM of concrete per day unless a deviation is approved by the CO.

3. Quality Control.

3.1. The Contractor's approved 3

rd party laboratory shall collect samples of fresh concrete in accordance with ASTM C172/C172M or equivalent British standard approved by the CO during each working day as required to perform tests specified herein. Make test specimens in accordance with ASTM C31/C31M or equivalent

British standard approved by the CO.

3.2. The 3

rd party approved laboratory shall perform concrete slump tests in accordance with ASTM C143/C143M or equivalent British standard approved by the CO. Take samples for slump determination from concrete during placement. Perform tests at the beginning of a concrete placement operation and for each batch (minimum) or every 16 CM (20 CY) (maximum) of concrete to ensure that specification requirements are met. In addition, perform tests each time test beams and cylinders are made.

3.3. Test air-entrained concrete for air content at the same frequency as specified for slump tests. Determine percentage of air in accordance with ASTM C231/C231M or equivalent British standard approved by the CO on samples taken during placement of concrete in forms.

3.4. The 3

rd party laboratory shall test for compressive strength in accordance with

ASTM C 39/C 39M or equivalent British standard approved by the CO and flexural testing IAW ASTM C78 or equivalent British standard approved by the CO. Make four test specimens for each set of tests. Test two specimens at 7 days, and the other two at 28 days. Concrete strength will be considered satisfactory when the minimum of the 28-day test results equals or exceeds the specified 28-day compressive strength. If the ratio of the 7-day strength test to the specified 28-day strength is less than 65 percent, make necessary adjustments for conformance. Frequency of compressive tests on concrete shall be not less than four test cylinders for each 38

CM (50 CY) of concrete, or no less than four cylinders per day. Concrete which is determined to be defective based on the strength acceptance criteria therein, shall be removed and replaced with acceptable concrete at the Contractor’s expense. At the sole discretion of the Government, the concrete can be accepted at a reduced unit price.

3.5. The Contractor shall allow the Government the opportunity to be present during the tests. All test reports shall be provided to the COR.

Salient characteristics of Hot- Mix Asphalt & Tack Coat:

1. Aggregates shall consist of crushed stone, crushed gravel, crushed slag, screenings, natural sand, and mineral filler, as required. The portion of material retained on the 4.75 mm (No.

4) sieve is coarse aggregate. The portion of material passing the 4.75 mm (No. 4) sieve and retained on the 0.075 mm (No. 200) sieve is fine aggregate. The portion passing the

0.075 mm (No. 200) sieve is defined as mineral filler. Submit sufficient materials to produce 90 kg (200 lbs) of blended mixture for mix design verification. Aggregate testing shall be performed by a 3rd party company for the cured asphalt, and asphalt components

(aggregate, sand, binder, etc.).

1.1. Course Aggregates shall consist of sound, tough, durable particles, free from films of material that would prevent thorough coating and bonding with the asphalt material and free from organic matter and other deleterious substances. The coarse aggregate particles shall meet the following requirements:

1.1.1. The percentage of loss shall not be greater than 40 percent after

500 revolutions when tested in accordance with ASTM C 131 or equivalent British standard approved by the CO.

1.1.2. The sodium sulfate soundness loss shall not exceed 12 percent, or the magnesium sulfate soundness loss shall not exceed 18 percent after five cycles when tested in accordance with ASTM C 88 or equivalent

British standard approved by the CO.

1.1.3. At least 75 percent by weight of coarse aggregate shall have at least two or more fractured faces when tested in accordance with U.S. Army Corps of

Engineers CRD-C 171. Fractured faces shall be produced by crushing.

1.1.4. The particle shape shall be essentially cubical, and the aggregate shall not contain more than 20 percent, by weight, of flat and elongated particles (3:1 ratio of maximum to minimum) when tested in accordance with ASTM D 4791 or equivalent British standard approved by the CO

1.1.5. Slag shall be air-cooled, blast furnace slag, and shall have a compacted weight of not less than 1,200 kg/cubic meter (75 lb/cu ft) when tested in accordance with ASTM C29/C29M or equivalent British standard approved by the CO.

1.1.6. Clay lumps and friable particles shall not exceed 0.3 percent, by weight, when tested in accordance with ASTM C 142/C 142M or equivalent

British standard approved by the CO.

1.2. Fine Aggregates shall consist of clean, sound, tough, durable particles. The aggregate particles shall be free from coatings of clay, silt, or any objectionable material and shall contain no clay balls. The fine aggregate particles shall meet the following requirements:

1.2.1. The quantity of natural sand (non-crushed material) added to the aggregate blend shall not exceed 15 percent by weight of total aggregate.

1.2.2. The individual fine aggregate sources shall have a sand equivalent value greater than 45 when tested in accordance with ASTM D 2419 or equivalent

British standard approved by the CO.

1.2.3. The fine aggregate portion of the blended aggregate shall have an uncompacted void content greater than 45.0 percent when tested in accordance with ASTM C 1252 Method A or equivalent British standard approved by the CO

1.2.4. Clay lumps and friable particles shall not exceed 0.3 percent, by weight, when tested in accordance with ASTM C 142/C 142M or equivalent

British standard approved by the CO.

2. Mineral filler shall be non-plastic material meeting the requirements of ASTM D 242/D

242M or equivalent British standard approved by the CO.

2.1. Gradation

2.1.1. The combined aggregate gradation shall conform to the

gradation specified in the table below, when tested in accordance with

ASTM C 136 and ASTM C 117 or equivalent British standard approved by the CO, and shall not vary from the low limit on one sieve to the high limit on the adjacent sieve or vice versa, but grade uniformly from coarse to fine. The JMF shall be within the specification limits

Gradations

Percent Passing by Mass (%)

Sieve Size (mm

/ Sieve #) Airfield

Surface

Course

Airfield

Intermediate

Course

Road

Surface

Course

Road

Intermediate

Course

25.0 / 1” 100 100 100 100

19 / 3/4” 100 90-100 100 76-96

12.5 / 1/2” 90-100 68-88 76-96 68-88

9.5 / 3/8” 69-89 60-82 69-89 60-82

4.75 / No. 4 53-73 45-67 53-73 45-67

2.36 / No. 8 38-60 32-54 38-60 32-54

1.18 / No. 16 26-48 22-44 26-48 22-44

0.60 / No. 30 18-38 15-35 18-38 15-35

0.30 / No. 50 11-27 9-25 11-27 9-25

0.15 / No. 100 6-18 6-18 6-18 6-18

0.075 / No. 200 3-6 3-6 3-6 3-6

2.2. Asphalt Binder

2.2.1. Asphalt cement binder shall conform to AASHTO M 320

Performance and Samples for this verification testing shall be obtained in accordance with ASTM D140/D140M or equivalent British standard approved by the CO and in the presence of the CO or COR.

2.3. Mix Design

2.3.1. The Contractor shall develop or submit a previously designed mix design that meets the specifications put forth in this statement of work with quote submittal.

The hot-mix asphalt shall meet the criteria of the Marshall Mix Design method.

A well-blended, representative sample of the Job Mix Formula (JMF), weighing no less than 34 kg (75 lbs), shall be provided to the COR for verification of mix design at least 7 days prior to initial delivery; deviations from this requirement shall be coordinated with the CO. If the Tensile Strength ratio (TSR) of the mix, as determined by ASTM D 4867/D 4867M or equivalent British standard approved by the CO is less than 75, the aggregates shall be rejected or the asphalt mixture treated with an anti-stripping agent. The amount of anti-stripping agent added shall be sufficient to produce a TSR of not less than 75; the anti-stripping agent shall be provided at no additional cost to the Government.

2.3.2. The Contractor shall utilize the Marshall Design method, warm-mix asphalt, or polymer modified binders, but should submit a request for information to the CO requesting the specifications to be utilized.

Marshall Mix Design Criteria

Test Property 75 Blow Mix Stability (N / pounds minimum) 9560 / 2150

(1)

Flow (0.25 mm / 0.01 inch) 8-16 (2)

Percent Air voids 4% Dust Proportion

(3) 0.8-1.2

TSR, Minimum Percent 75%

TSR Conditioned Strength (minimum kPa/psi) 415 / 60

Percent Voids in Mineral Aggregate (minimum) Intermediate Courses 13%

Surface Course 14%

Notes:

1. This is a minimum requirement. The average during construction shall be significantly higher than this number to ensure compliance with the specifications.

2. The flow requirement is not applicable for Polymer Modified Asphalts.

3. Dust Proportion is calculated as the aggregate content, expressed as a percent of mass, passing the 0.075 mm (No. 200 sieve), divided by the effective asphalt content, in percent of total mass

4. Calculate VMA in accordance with AI MS-2, based on ASTM D2726/D2726M or equivalent British standard approved by the CO bulk specific gravity for the aggregate.

2.4. The Contractor shall submit four copies of the proposed JMF test results for approval in writing, for approval, at least 14 days prior to the start of the Government identified test section. The test results should at a minimum include:

2.4.1. Percent passing each sieve size.

2.4.2. Percent of asphalt cement.

2.4.3. Percent of each aggregate and mineral filler to be used.

2.4.4. Asphalt viscosity grade, penetration grade, or performance grade.

2.4.5. Number of blows of hammer per side of molded specimen.

2.4.6. Laboratory mixing temperature.

2.4.7. Lab compaction temperature.

2.4.8. Temperature-viscosity relationship of the asphalt cement.

2.4.9. Plot of the combined gradation on the 0.45 power gradation chart, stating the nominal maximum size and theoretical maximum aggregate size.

2.5. Graphical plots and summary tabulation of stability, flow, air voids, voids in the mineral aggregate, and unit weight versus asphalt content as shown in AI MS-02.

Summary tabulation shall include individual specimen data for each specimen tested.

2.5.1. Specific gravity and absorption of each aggregate.

2.5.2. Percent natural sand.

2.5.3. Coarse Aggregate Angularity

2.5.4. Sand Equivalence Test

2.5.5. Fine aggregate angularity.

2.5.6. Percent flat or elongated particles (in coarse aggregate).

2.5.7. Tensile Strength Ratio and wet/dry specimen test results.

2.5.8. Anti-strip agent (if required).

2.5.9. List of all modifiers.

2.6. Adjustments to the JMF.

2.6.1. The JMF for each mixture shall be in effect until a new formula is approved in writing by the CO. Should a change in sources of any materials be made, a new mix design shall be performed and a new JMF approved before the new material is used.

The Contractor will be allowed to make minor adjustments within the specification limits to the JMF to optimize mix volumetric properties. Adjustments to the original

JMF shall be limited to plus or minus 4 percent on the 4.75 mm (No. 4) and coarser sieves; plus or minus 3 percent on the 2.36 mm (No. 8) to 0.30 mm (No. 50) sieves;

and plus or minus 1 percent on the 0.15 mm (No. 100) sieve. Adjustments to the

JMF shall be limited to plus or minus 1.0 percent on the 0.075 mm (No. 200) sieve.

Asphalt content adjustments shall be limited to plus or minus 0.40 percent from the original JMF. If adjustments are needed that exceed these limits, a new mix design shall be developed.

Marshall Mix Design Criteria

Test Property 75 Blow Mix Stability (N / pounds minimum) 9560 / 2150

(1)

Flow (0.25 mm / 0.01 inch) 8-16 (2)

Percent Air voids 4% Dust Proportion

(3) 0.8-1.2

TSR, Minimum Percent 75%

TSR Conditioned Strength (minimum kPa/psi) 415 / 60

Percent Voids in Mineral Aggregate (minimum) Intermediate Courses 13%

Surface Course 14%

Notes:

5. This is a minimum requirement. The average during construction shall be significantly higher than this number to ensure compliance with the specifications.

6. The flow requirement is not applicable for Polymer Modified Asphalts.

7. Dust Proportion is calculated as the aggregate content, expressed as a percent of mass, passing the 0.075 mm (No. 200 sieve), divided by the effective asphalt content, in percent of total mass

8. Calculate VMA in accordance with AI MS-2, based on ASTM D2726/D2726M or equivalent British standard approved by the CO bulk specific gravity for the aggregate.

2.7. Execution

2.7.1. The asphalt binder material shall be heated avoiding local overheating and providing a continuous supply of the asphalt material to the mixer at a uniform temperature. The temperature of unmodified asphalts shall not exceed 160 degrees C

(330 degrees F) when added to the aggregates. Performance Graded (PG) asphalts shall be within the temperature range of 141 degrees C (285 degrees F) to 166 degrees

C (330 degrees F) when added to the aggregates.

2.8. Preparation of Mineral Aggregate

2.8.1. The aggregate for the mixture shall be heated and dried prior to mixing. No damage shall occur to the aggregates due to the maximum temperature and rate of heating used. The temperature of the aggregate and mineral filler shall not exceed

175 degrees C (350 degrees F) when the asphalt cement is added. The temperature shall not be lower than is required to obtain complete coating and uniform distribution on the aggregate particles and to provide a mixture of satisfactory workability.

2.9. Preparation of Hot-Mix Asphalt

2.9.1. The aggregates and the asphalt cement shall be weighed or metered and introduced into the mixer in the amount specified by the JMF. The combined materials shall be mixed until the aggregate obtains a thorough and uniform coating of asphalt binder (testing in accordance with ASTM D2489/D2489M or equivalent

British standard approved by the CO may be required by the CO) and is thoroughly distributed throughout the mixture. The moisture content of all hot-mix asphalt upon discharge from the plant shall not exceed 0.5 percent by total weight of mixture as measured by ASTM D1461 or equivalent British standard approved by the CO.

2.10. Transportation of Materials

2.10.1. Transporting. The hot-mix asphalt shall be transported from the mixing plant to the site in clean, tight vehicles. Hauling over freshly placed material will not be permitted until the material has been compacted as specified, and allowed to cool to

60 degrees C (140 degrees F).

2.10.1.1. Delivery Quantities. The Contractor shall be capable of to delivering a minimum of 32 MT of asphalt in a day and truck sizes will not exceed 32 MT due to Government paver capabilities unless a deviation is approved by CO

2.10.1.2. Delivery Temperature. Temperature upon arrival at the job site shall be between 141 and 146 degrees C (285 and 295 degrees F). The COR shall be present to record each truck’s temperature upon arrival. If the material fails to meet these temperature requirements, the entire truck will be rejected, the material removed, and replaced at no additional cost to the Government.

2.10.1.3. Trucks used for hauling hot-mix asphalt shall have tight, clean, and smooth metal beds. To prevent the mixture from adhering to them, the truck beds shall be lightly coated with a minimum amount of paraffin oil, lime solution, or other approved material. Petroleum based products shall not be used as a release agent.

Each truck shall have a suitable cover to protect the mixture from adverse weather. When necessary to ensure that the mixture will be delivered to the site at the specified temperature, truck beds shall be insulated or heated and covers

(tarps) shall be securely fastened.

1. Tack Coat

1.1 The Contractor shall select a prime coat and tack coat material in compliance with the specifications in this section to use. All materials shall be submitted for approval to the CO prior to use. Emulsified asphalts of grades SS-1 or SS-1h are the preferred material; however, the Government will allow the usage of acceptable alternates as approved by the CO.

1.2 Cutback asphalt shall conform to American Society for Testing and Materials (ASTM)

D 2028, Standard Specification for Cutback Asphalt (Rapid-Curing Type), cutback grades RC-70 or RC- 250 or equivalent British standard approved by the CO. These materials perform better than emulsions in cool weather construction.

1.3 Paving grade asphalt shall conform to the table below.

ASTM Standard Grade

ASTM D 946, Standard Specification for

Penetration-Graded Asphalt Cement for Use in Pavement Construction or equivalent

British standard approved by the CO

Penetration grade 200-300, 120-150, or

85-100

ASTM D 3381, Standard Specification for

Viscosity-Graded Asphalt Cement for Use in

Pavement Construction or equivalent British standard approved by the CO

Viscosity grade AC 2.5, AC 5, or AC 10

ASTM D 3381 or equivalent British standard approved by the CO

Aged residue viscosity grades AR 1000, AR 2000, or AR 4000

1.1. Emulsions, either anionic or cationic, can be used for tack coats. Anionic emulsion shall conform to ASTM D 977, Standard Specification for Emulsified Asphalt, grades RS-1, MS-1, HFMS-1, SS-1 or SS-1h. Cationic emulsions shall conform to

ASTM D 2397, Standard Specification for Cationic Emulsified Asphalt, grades CRS-

1, CSS-1, and CSS-1h or equivalent British standard approved by the CO. Grades SS-

1 and CSS-1h are made with harder base asphalt and are recommended for airfield pavements. Grades RS-1, SS-1, and SS-1h are widely used as tack coat materials.

1.2. Emulsified asphalt should be diluted with no more than an equal volume of water.

The base asphalt used to manufacture the emulsion shall show a negative spot when tested in accordance with AASHTO T 102 using standard naphtha or equivalent

British standard approved by the CO.

1.3. The equipment for heating the bituminous material shall be steam, electric, or hot oil heaters. Steam heaters shall consist of steam coils and equipment for producing steam, so designed that the steam cannot get into the material. Fix an armored thermometer to the tank with a temperature range from 4.4 to 204.4 degrees C (40 to

400 degrees F) so that the temperature of the bituminous material may be determined at all times.

2. Execution.

2.1 Application of Tack Coat.

2.1.1 The application rates specified in this paragraph are the rates for the asphalt residue content and do not account for the water or solvent if an emulsion or cutback is used. Tack coats shall be applied at the rate of

0.3 to 0.7 liter per square meter (0.05 to 0.15 gallons per square yard).

If, at the prescribed application rate, the material flows off the surface, the application rate shall be adjusted at the direction of the COR.

2.1.2 A calibrated bituminous distributor capable of the required application rates will apply prime and tack coats. The equipment will include a self-powered pressure bituminous material distributor and equipment for heating bituminous material. The distributor will be designed, equipped, maintained, and operated so that bituminous material at even heat may be applied uniformly on variable widths of surface at the specified rate.

The allowable variation from the specified rate will not exceed 10 percent. Distributor equipment will include a tachometer, pressure gauges, volume-measuring devices or a calibrated tank, and a thermometer for measuring temperatures of tank contents. The distributor will be self-powered and will be equipped with a power unit for the pump and full circulation spray bars adjustable laterally and vertically.

2.1.3 The application temperature will provide an application viscosity between

10 and 60 seconds, Saybolt Furol, or between 20 and 120 square millimeters per second (20 and 120 centistokes), kinematic. The table below shows the normal application temperatures for each material type

Asphalt Type Grade Application Temperature

Liquid Asphalts

SC-70 50-107 °C (120-225 °F)

SC-250 75-132 °C (165-270 °F)

MC-30 29-87 °C (85-190 °F)

MC-70 50-107 °C (120-225 °F)

MC-250 75-132 °C (165-270 °F)

RC-70 50-90 °C (120-200 °F)

RC-250 75-120 °C (165-250 °F)

Viscosity and Aged

Residue Grade Asphalts

AC 2.5 +132 °C (+270 °F)

AC 5 +137 °C (+280 °F)

AC 10 +137 °C (+280 °F)

AR 1000 +135 °C (+275 °F)

AR 2000 +140 °C (+285 °F)

AR 4000 +143 °C (+290 °F)

Penetration Grade

Asphalt

200-300 +130 °C (+265 °F)

120-150 +132 °C (+270 °F)

85-100 +137 °C (+280 °F)

Emulsions

RS-1 20-60 °C (70-140 °F)

MS-1 20-70 °C (70-160 °F)

HFMS-1 20-70 °C (70-160 °F)

SS-1 20-70 °C (70-160 °F)

SS-1h 20-70 °C (70-160 °F)

CRS-1 52-85 °C (125-185 °F)

CSS-1 20-70 °C (70-160 °F)

CSS-1h 20-70 °C (70-160 °F)

4.1.4. Asphalt material shall be applied at the specified rate with uniform distribution over the surface to be treated. All areas and spots missed by the distributor will be properly treated by hand spray. If required, clean, dry sand will be used to soak up excess bituminous material.

2.2 Application of Prime Coat

2.2.1 The application rates specified in this paragraph are the rates for the asphalt residue content and do not account for the water or solvent if an emulsion or cutback is used.

Tack coats shall be applied at the rate of 0.8 to 1.6 liter per square meter (0.18 to 0.35 gallons per square yard). If, at the prescribed application rate, the material flows off the surface, the application rate shall be adjusted at the direction of the COR.

2.2.2 A calibrated bituminous distributor capable of the required application rates will apply prime and tack coats. The equipment will include a self-powered pressure bituminous material distributor and equipment for heating bituminous material. The distributor will be designed, equipped, maintained, and operated so that bituminous material at even heat may be applied uniformly on variable widths of surface at the specified rate. The allowable variation from the specified rate will not exceed 10 percent. Distributor equipment will include a tachometer, pressure gauges, volume-measuring devices or a calibrated tank, and a thermometer for measuring temperatures of tank contents. The distributor will be self-powered and will be equipped with a power unit for the pump and full circulation spray bars adjustable laterally and vertically.

2.2.3 The application temperature will provide an application viscosity between 10 and 60 seconds, Saybolt Furol, or between 20 and 120 square millimeters per second (20 and 120 centistokes), kinematic. The table below shows the normal application temperatures for each material type.

2.2.4 Asphalt material shall be applied at the specified rate with uniform distribution over the surface to be treated. All areas and spots missed by the distributor will be properly treated by hand spray. If required, clean, dry sand will be used to soak up excess bituminous material.

Asphalt Type Grade Application Temperature

Liquid Asphalt

SC-70 50-107 °C (120-225 °F)

SC-250 75-132 °C (165-270 °F)

MC-30 29-87 °C (85-190 °F)

MC-70 50-107 °C (120-225 °F)

MC-250 75-132 °C (165-270 °F)

RC-70 50-90 °C (120-200 °F)

RC-250 75-120 °C (165-250 °F)

Viscosity Grade Asphalt

AC 2.5 +132 °C (+270 °F)

AC 5 +137 °C (+280 °F)

AC 10 +137 °C (+280 °F)

AR 1000 +135 °C (+275 °F)

AR 2000 +140 °C (+285 °F)

AR 4000 +143 °C (+290 °F)

Penetration Grade

Asphalt

200-300 +130 °C (+265 °F)

120-150 +132 °C (+270 °F)

85-100 +137 °C (+280 °F)

Emulsions

RS-1 20-60 °C (70-140 °F)

MS-1 20-70 °C (70-160 °F)

HFMS-1 20-70 °C (70-160 °F)

SS-1 20-70 °C (70-160 °F)

SS-1h 20-70 °C (70-160 °F)

CRS-1 52-85 °C (125-185 °F)

CSS-1 20-70 °C (70-160 °F)

CSS-1h 20-70 °C (70-160 °F)

General Information:

THIS ANNOUNCEMENT IS NOT A SOLICITATION AND IS BEING USED FOR

THE PURPOSEOF MARKET ANALYSIS ONLY.

This notice is being published in accordance with Federal Acquisition Regulations (FAR) Part

5.101 requiring dissemination of information for proposed contract actions and FAR

10.001(a)(2)(ii) which requires conducting market research before soliciting offers for acquisitions with an estimated value in excess of the simplified acquisition threshold. The

Government is seeking industry’s input to determine the availability of qualified sources with the technical capability to fulfill the requirement described above. No contract awards will be made from this notice and no solicitation is available on FBO or any other bulletin board, posting room, or clearinghouse at this time. In order to develop a sound acquisition strategy, early industry participation is highly encouraged; however, participation in this effort is strictly voluntary. All costs associated with responding to this RFI will be solely at the interested party’s expense. The Government will not reimburse costs and will not be liable for any costs associated with responses to this RFI. Respondents will not be notified of the responses to this notice. Responses to this notice are not considered offers and cannot be accepted by the

Government to form a binding contract. All RFI responses will be used in whole or in part for determining the most effective acquisition strategy for base course, concrete, and hot-mix asphalt acquisitions or similar requirements. Requested information will be used within the Air Force to facilitate decision making and will not be disclosed outside the agency.

Response Guidelines:

All responses to this RFI must be provided as an attachment in an e-mail message addressed to the Point of Contact (POC), below with the subject line “Response to RFI” no later than 1630

GMT on 8 March 2022.

Only electronic responses will be accepted. Responses submitted by any other means will not be considered.

Requested Information:

The following is requested from interested companies;

1. Please indicate if your company is willing/able to provide base course, concrete, and asphalt or if there are any reasons that prevent your company from providing a quote/proposal should a formal solicitation be issued.

2. Please provide brochures/descriptive literature commonly provided to the general public if possible.

3. Please provide any catalogs/price lists for items listed if possible.

4. Please provide approximate delivery and installation timelines.

5. Please provide if you are registered in SAM.

6. Full Vendor Name, Address and Current DUNS/CAGE Code.

Please submit a written response via scan/email-attachment on company letter head to points of contract listed below.

Points of Contact:

Primary POC: 2d Lt MaKayla Hansen

Phone: 00 44 (0) 1638 523082

Email: makayla.hansen.2@us.af.mil

Contracting Office Address:

48 CONS/PKA - Lakenheath, Building 977

Boston Drive

RAF Lakenheath, Brandon, Suffolk IP27 9PN mailto:makayla.hansen.2@us.af.mil