Performance based specification for hotmix …

1 Performance based specification SP/SP23:051014 FOR hotmix asphalt wearing course surfacing Page 1 of 18 TNZ P/23: 2005 Performance based specification FOR hotmix asphalt wearing course surfacing 1. SCOPE This specification sets out the Performance requirements for the following types of asphalt as wearing courses: The supply and laying of Open Graded Porous asphalt (OGPA); The supply and laying of Textured High Stress Resistant type asphalts, such as Stone Mastic asphalt ; and The supply and laying of Dense Graded Asphaltic Concrete (DGAC). 2. DEFINITIONS Hot Mix asphalt Hot Mix asphalt (HMA) is a mixture of bituminous binder and aggregate, with or without added mineral filler, produced in a mixing plant.

2 It is delivered spread and compacted while hot. Coarse Aggregate The Coarse Aggregate is the fraction of the aggregate components retained on a test sieve. Fine Aggregate Fine aggregate is the fraction of the aggregate components passing the test sieve, excluding added mineral fillers. Mineral Filler Mineral Filler is finely ground particles of limestone, hydrated lime, Portland cement or other non-plastic mineral matter, predominantly finer than that is added to the mix. Binder Unless specified in the specific contract requirements binder is penetration grade bitumen complying with TNZ M/1 specification . Job Mix Formula TNZ P/23: 2005 Performance based specification SP/SP23:051014 FOR hotmix asphalt wearing course surfacing Page 2 of 18 The Job Mix Formula (JMF) is the combined aggregate particle size distribution and total binder content that is chosen by the Contractor and produces a HMA that complies with the criteria specified in Table 2.

3 Mix Control Envelope The Mix Control Envelope (MCE) is the range of allowable variation from the JMF allowed during production. The MCE may include some or all of the sieves required to produce the particle size distribution. Voids in the Mineral Aggregate The Voids in the Mineral Aggregate (VMA) is the volume of intergranular void space between the aggregate particles of a compacted mixture that includes the air voids and the effective binder content, expressed as a percentage of the total volume of the sample. wearing Mix A mix applied as the uppermost layer in a pavement subjected to the wearing action of traffic. Reclaimed asphalt Pavement (RAP) Reclaimed asphalt Pavement (RAP) is material comprising old asphalt that has been processed by crushing and/or screening to produce a free flowing and consistent product.

4 Maximum size The maximum size of a mix is the smallest sieve size at which 100% of the aggregate passes. Nominal Size The nominal size of a mix is the smallest sieve size at which more than 90% of the aggregate passes. Refusal Density The density of a laboratory compacted specimen, compacted in accordance with using the ServopacTM using compaction 250 cycles. Theoretical Maximum Specific Gravity Theoretical Maximum Specific Gravity (MSG) is a theoretical relative density of the asphalt with no air voids (see ASTM D 2041) TNZ P/23: 2005 Performance based specification SP/SP23:051014 FOR hotmix asphalt wearing course surfacing Page 3 of 18 Lot Definitions A Manufacturing Lot shall be deemed to be the quantity of a specified mix manufactured at a specific facility under essentially uniform process conditions with consistent ingredients resulting in a homogeneous product.

5 A Production Lot shall be made up of manufactured material (within a manufacturing lot) which has been handled to regulate and conserve characteristics of homogeneity and workability in suitable manner. A Field Lot shall be representative of production mix (within a production lot) which has been continuously laid under essentially constant conditions to achieve an end product homogeneous in appearance. 3 Performance REQUIREMENTS The specified Performance requirements for the HMA controlled by this specification are given in Table 1, Table 2 and Table 3. The specific contract requirements given in Schedule A, specify design values for layer thickness, binder type, aggregate polished stone value (PSV), texture depth, mix designation and any other requirements.

6 Polished Stone Value Requirements. At least 85 % of the coarse aggregate shall be obtained from an aggregate source(s) of the required Polished Stone Value (PSV). Blending of coarse aggregates from different sources with different PSV s, including PSVs lower than that required, to theoretically achieve the specified value is prohibited. 4 CONTRACT QUALITY PLAN The Contractor shall submit to the Engineer a Contract Quality Plan (CQP) detailing the procedures to be followed to ensure compliance with the specified Performance requirements and specific criteria detailed in this specification . The Engineer and Contractor will mutually agree to its content and appropriateness.

7 The quality plan shall define the MCE, which shall have allowable variations reflecting current industry best practice. TNZ P/23: 2005 Performance based specification SP/SP23:051014 FOR hotmix asphalt wearing course surfacing Page 4 of 18 TABLE 1 HMA Raw Material Properties Table 1a Binder Properties Test Property Test Method Requirements Frequency Comments Penetration Grade Bitumen Compliance with M/1 Modified Binder Softening Point AGPT/T157 or ASTM D36 Report Value Modified Binder Torsional Recovery AGPT/T154 Report Value Modified Binder Viscosity AGPT/T132 or ASTM D4402 Report Value One representative test per production batch of modified binder.

8 Requirements to be included in Schedule A TNZ P/23: 2005 TABLE 1 HMA Raw Material Properties Table 1b Aggregate Properties Test Property Test Method Requirements Frequency Comments Coarse Aggregate Properties Crushing Resistance Dense Graded asphalt (Table 2c) Other Types of HMA (Table 2a and 2b) NZS 4407 Test 200 kN min 230 kN min Weathering Resistance NZS 4407 Test AA or BA Polished Stone Value BS EN 1097 Part 8 As per Specific Contract Requirements and T/10 As per BCA 9805 Quality Assurance of Aggregates for Chipseals and Bituminous Mixes Current requirements for TNZ M/10 Los Angeles Abrasion Loss AS or NZS 4407 Test Report Value Wet/Dry Strength Variation AS Report Value Water Absorption AS or ASTM C127 Report Value Representative test values of the aggregate(s) to be used in the contract A number of new tests have been introduced in order to explore alternative means of assessing aggregate quality for use in HMA.

9 Fine Aggregate Properties Crushing Resistance NZS 4407 Test 200kN min (parent rock) Sand Equivalent, or NZS 4407 Test 35 min, or Clay Index (< ) NZS 4407 Test 3 max As per BCA 9805 Quality Assurance of Aggregates for Chipseals and Bituminous Mixes Current requirements for TNZ M/10 Water Absorption AS or ASTM C128 Report Value Degradation Factor AS Report Value Representative test result of the aggregate(s) to be used in contract A number of new tests have been introduced in order to explore alternative means of assessing aggregate quality for use in HMA. Performance based specification SP/SP23: 051014 FOR hotmix asphalt wearing course surfacing Page 5 of 18 TNZ P/23: 2005 TABLE 2 wearing course asphalt Performance Criteria 2(a): Open Graded Porous HMA Performance Requirement Test/Reference Method Test Value Comments 1.

10 Field Criteria Surface ride NAASRA roughness To be specified in Schedule A Deviation under 3m straight edge (mm) 5 max At construction joints, and any localised defect. Permeability Field Permeability (sec) TNZ Test Method, refer Notes Appendix 12 max At time of laying, not applicable to high strength OGPA, similar to P/11 PA 14 Permeability Relative Hydraulic Conductivity (Reciprocal seconds) BS DD 229 Report Value Data gathering only not contractually binding 2. Mix Design Properties Binder Drain-down (%) asphalt Particle Loss (%) Retained Tensile Strength (%) AGPT / T 235 (flask) or BS DD 232 (basket) AGPT / T 236 Unconditioned Moisture Conditioned ASTM D4867 as modified by TNZ P/11 max at 8 C above nominated mixing temp 15 max 20 max Report Value 80 min Heavy/Very Heavy Traffic Medium traffic Performance based specification SP/SP23: 051014 FOR hotmix asphalt wearing course surfacing Page 6 of 18 TNZ P/23: 2005 Performance Requirement Test/Reference Method Test Value Comments 3.