VicRoads
SECTION520MATERIALS AND CONSTRUCTION PLANT FOR ROLLER COMPACTED CONCRETE PAVEMENT COURSES
##This section cross-references Sections521 and 801.
If any of the above sections are relevant, they should be included in the specification.
If any of the above sections are not included in the specification, all references to those sections should be struck out, ensuring that the remaining text is still coherent:
520.01DESCRIPTION
This section covers the requirements for materials and construction plant for the construction of roller compacted concrete courses.
520.02DEFINITIONS
Concrete for Roller Compaction
Concrete for roller compaction is a mixture of crushed rock fragments, sand, cementitious materials and water produced at a controlled mixing plant for spreading and compaction on site to produce roller compacted concrete.
Fine Aggregates
Fine aggregates are aggregates passing a 4.75mm ASsieve.
Coarse Aggregates
Coarse aggregates are aggregates retained on a 4.75mm ASsieve.
Assigned Los Angeles Abrasion Loss
The assigned LosAngeles Abrasion Loss is a hardness rating derived from LosAngeles Abrasion Loss test results and is assigned to each source by VicRoads on the basis of past test data obtained from testing products.
520.03CONCRETE MATERIALS
(a)Source Rock
Source rock shall comply with the requirements of Section 801 Source Rock for the Production of Crushed Rock and Aggregates.
(b)Coarse Aggregate
Coarse aggregate shall consist of clean, hard, durable angular rock fragments of uniform quality. It shall be free from clay, clay lumps, salt, organic matter or other substances detrimental to concrete.
(c)Fine Aggregates
Fine aggregates shall consist of clean, hard, durable, crusher fines and/or naturally occurring sands, and shall be free from clay, clay lumps, soft or flaky particles, shale, salt, alkali, organic matter, soil or other substances detrimental to concrete. Where necessary to meet the specified grading, fly ash may be added as fine aggregate.
Crusher fines shall have a minimum degradation factor of60.
(d)Cement
Cement shall be supplied by the Contractor and shall comply with the requirements of AS3972 at the time of usage. Cement shall be from one manufacturer and be of one brand, type and grind.
The use of other pozzolaine additives shall be subject to prior approval by the Superintendent.
The Superintendent's approval shall be obtained prior to changing the source and quality of the nominated cement.
(e)Fly Ash
Fly ash shall comply with the requirements of AS3582.1.
(f)Water
Water shall be clear and substantially free from detrimental impurities such as oils, salts, organic substances, acids, alkalis and vegetable substances. The amounts of chloride and sulphate shall each be not greater than0.03%.
(g)Admixtures
The use of admixtures shall be subject to the approval of the Superintendent.
The Contractor shall submit to the Superintendent details of the proposed source and nature of such materials and the proposed amounts to be added.
Admixtures shall conform with the requirements of AS1478 and shall not reduce the strength of concrete below that specified. Admixtures shall not contain chlorides, chlorine, sulphur, sulphides or sulphites, or any other substance detrimental to concrete.
520.04AGGREGATE PRODUCT
(a)The coarse aggregate used in the product shall comply with the requirements of Table520.041.
Table 520.041 / Total of Marginal and Unsound Rock% (max) / Unsound Rock %
(max)
10 / 5
(b)The Flakiness Index of each separate sized coarse aggregate shall not exceed35%.
(c)Before the addition of cement the aggregate product shall comply with the requirements of Table520.042.
Table 520.042 / Test / Test ValueLiquid Limit % (max) / 25
Plasticity Index (max) / 3
(d)The grading of the combined coarse and fine aggregates shall lie within the limits specified in Table520.043.
Table 520.043 / Sieve SizeAS (mm) / Percentage Passing
(by mass)
26.5 / 100
19.0 / 83 100
13.2 / 72 93
9.5 / 66 85
4.75 / 51 69
2.36 / 38 56
1.18 / 28 46
0.600 / 18 – 36
0.300 / 11 – 27
0.150 / 6 – 18
0.075 / 2 – 8
520.05MIX DESIGN
(a)General
The proportions of the concrete mix shall be designed by the Contractor to satisfy the strength requirement and to be satisfactorily placed and compacted by the proposed paving equipment.
The Contractor shall submit for the approval of the Superintendent, the mix design(s) and samples of mix constituents at least six weeks prior to the proposed date for commencement of supply of the concrete.
No concrete shall be supplied until the mix has been approved in writing.
Approval by the Superintendent of a submitted concrete mix design will not constitute acceptance of the concrete. Final acceptance will be subject to the compliance of the concrete upon testing.
Where changes to an approved mix are proposed, the Contractor shall provide details and materials for mix approval in accordance with the above requirements.
(b)Requirements
The mix shall comply with the requirements of Table520.051.
Table520.051
Cement Content(min) / Fly Ash Content *
(max) / Mean Compressive Strength **
(min)
250 kg/m3 / 20% / 40 MPa
*percentage of total cementitious material by mass
**compacted to 98% Modified maximum dry density at 0.5% dry of Modified optimum moisture content and cured for 28days, to AS1012 Part8.
520.06BATCHING, MIXING AND TRANSPORT
The mixing plant shall be capable of homogeneously mixing low moisture cement bound materials.
Drum type mixers, whether tilting or split, and truck mounted agitators shall not be used.
Coarse aggregate, fine aggregate and cementitious materials shall be separately fed into the mixer. Flyash may be added as a blend with cement.
(a)Mixing
(i)Batch Mixing
The dry materials shall be dry mixed for at least 15seconds. After the addition of water mixing shall be continued until a homogeneous mixture is obtained.
(ii)Continuous Mixing
The concrete shall be discharged into trucks such that segregation is minimized. Mixer and mixer paddle surfaces shall be kept free of hardened concrete and other contamination.
(b)Tolerances
(i)Grading
The tolerances on the job mix grading aim for the combined aggregate delivered to the mixer shall be as specified in Table520.061. The aggregates shall be sampled from the hopper feed belt during a test run using aggregates without the addition of cement, water or admixtures.
Table 520.061 / Sieve SizeAS (mm) / Tolerance on Percentage Passing
(by mass)
19.0 / 3
13.2 9.5 / 5
4.75 0.600 / 4
0.300 / 3
0.150 0.075 / 2
(ii)Cementitious Materials
After mixing, the cementitious materials content as a percentage by mass of the dry concrete materials shall be within plus2.0 to minus0.5 of the job mix cement content.
(iii)Moisture
The mixing plant shall be fitted with a water flow meter to ensure a constant water feed rate. The moisture content of the mixture at the point of delivery, expressed as a percentage by mass, shall be within plus0.5 to minus0.5 percent of the target moisture content nominated by the Contractor.
(c)Transporting
Concrete shall be transported from the mixer to the placing site in clean containers equipped with protective covers where lead distances are greater than2km. The maximum time between mixing and delivery to the paver shall be 15minutes. This time may be extended if set retarders are used, provided that crusts of partially hardened material do not develop.
(d)Delivery Dockets
Where material is supplied from plant(s) offsite, the Contractor shall make delivery dockets available for inspection on request by the Superintendent.
Delivery dockets shall show:
(i)name of the supplier, and location of plant;
(ii)docket number;
(iii)name of user;
(iv)project name and location (or contract number);
(v)registered number or fleet number of the vehicle;
(vi)date and time of loading;
(vii)type of material;
(viii)volume of material supplied.
520.07CONSTRUCTION PLANT
Pavers shall be capable of paving dry cement bound aggregates, be heavy duty, self propelled, track driven and have sufficient mass and stability to spread, compact and finish concrete to the specified layer thickness and width, smoothness and surface texture without segregation. The screed shall be adjustable and capable of placing pavement up to 4mwidth for single lane construction or 9mwidth for multilane construction and shall have automatic and manual level controls separately operating both sides.
Side forms shall form the edge of the pavement either vertically or 15° from the vertical within the specified tolerance for line and width.
520.08JOINT SEALANTS
(a)General
Permanent seals shall be either a neoprene compression seal or an insitu cast silicone sealant.
A full technical description of the proposed sealant, and method of installation recommended by its manufacturer shall be submitted for approval by the Superintendent at least 8weeks prior to installation.
The Contractor shall obtain a Certificate of Compliance, from a NATA accredited laboratory, showing that the sealant meets all of the requirements specified in Clause520.08(b) and(c), as appropriate.
(b)Neoprene Compression Seals
Neoprene compression seals shall conform to the requirements of ASTMD2628 "Specification for Preformed Polychloroprene Elastomeric Joint Seals for Concrete Pavements".
The size of the seal shall be selected to suit the sealant reservoir dimensions shown on the drawings.
The seal shall be dimensioned such that its maximum operating width does not exceed 80% of its uncompressed width.
(c)Silicone Seals
Silicone seals shall be formed from a silicone material conforming to the requirements of Table520.081.
Table520.081
Test Method / Test / RequirementsUNCURED
MIL S 8802 / Flow maximum / 5 mm maximum
ASTM D 792 / Specific gravity / 1.4 to 1.515
MIL S 8802 / Extrusion rate / 90 to 250 GM/minutes
MIL S 8802 / Tack free time / 35 to 75 minutes
CURED
ASTM D 2240 / Durometer / 15 to 25
ASTM D 412 / Die C modulus at 150% elongation / 310 KPa maximum
ASTM D 412 / Die D elongation % / 1200 minimum
RTA T1192 / Adhesion to concrete / Pre-treatment as per RTA T1193,
Extension to 70%
Compression to 50%
No more than 10% failure over the cross-sectional area
PERFORMANCE
ASTM C 7197 / Movement % / +100 to 50
ASTM D 7937 / Accelerated weathering at 5000 hours / No cracks, blisters or bond loss
Sections of material prepared for testing in the cured state shall be cured 7days at 251C and 50%Relative Humidity.
The silicone joint sealant shall be grey in colour and shall be stored and installed in accordance with the manufacturer's recommendations.
520.09CURING COMPOUNDS
(a)General
The compound shall be suitable for spray application to freshly laid concrete at the low sheen stage of drying at the application rates specified in Section521. At the low sheen stage the surface is still soft to touch but without free water.
Prior to the application of a curing compound the Contractor shall submit to the Superintendent a Certificate of Compliance certifying that the proposed compound meets the requirements of the Specification. The manufacturer's technical data sheet shall also be submitted.
(b)Chlorinated Rubber Curing Compound
The compound shall comply with the following requirements:
(i)Material Composition
Chlorinated rubber curing compound shall consist of not less than 20% by mass nonvolatile component made up of only chlorinated rubber and chlorinated paraffins. The nonvolatile component shall comprise not less than 60% by mass chlorinated rubber. The nonvolatile component shall be dissolved in a suitable solvent other than reclaimed solvent.
The compound shall be coloured with a fugitive dye (colour other than grey). The dye shall be uniformly mixed throughout the compound and shall completely lose its colour within four weeks from application. The product shall be a uniform, free flowing liquid free from contamination.
(ii)Non Volatile Content
When determined in accordance with RTANSW Test MethodT865, the nonvolatile content of the compound shall be not less than 20% by mass.
(iii)Residue on 150 Micron Sieve
When tested in accordance with RTANSW Test MethodT534, the residue of material retained on the sieve shall not exceed 0.2% of mass.
(iv)Viscosity at 25C
When tested in accordance with AS1580.214.5 the viscosity of the compound at 25C shall be between 0.02 and 0.20pascal seconds.
(v)Moisture Retention performance
When tested in accordance with RTANSW Test MethodT864, the Efficiency Index after 72hours at 38C and 32% relative humidity shall not be less than90%.
(vi)Infrared Spectrum
The infrared spectrum of the residue remaining in the dish after testing in accordance with AS1580.301.1 shall be recorded in accordance with RTANSW Test MethodT1005.
520.10MINIMUM TESTING REQUIREMENTS
The Contractor shall test the roller compacted concrete at a frequency which is sufficient to ensure that all material supplied under the Contract complies with the specified requirements. The frequency shall not be less than that shown in Table520.101, except that the Superintendent may agree to a lower frequency where the Contractor has implemented a system of statistical process control and can demonstrate that such lower frequency is adequate to assure the quality of the product.
Table 520.101
Test / Minimum Frequency of TestingGrading / On each day one per 300 tonne or part thereof
Unsound Rock Content / On each day one per 300 tonne or part thereof
Cement Content / On each day one per 100 tonne or part thereof
Moisture Content / On each day one per 100 tonne or part thereof
Plasticity Index / In each month one per 20,000 tonne or part thereof
Flakiness Index of Coarse Aggregate 10mm and Larger / At monthly intervals
Degradation Factor of Crusher Fines / At monthly intervals