Rubberized Single Chip Seal Project

2026-11-03

ITEM 1 - RUBBERIZED SINGLE CHIP SEAL ( SY ) 1 . GENERAL Work under this Item shall consist of the Contractor furnishing and applying a 20 % Asphalt - Rubber Surface Treatment on properly prepared bituminous streets . Bid quantities are approximate only ; payment shall be for actual quantities applied to streets . Streets to be stone sealed shall be selected by the Director or his / her Designee . Measurements of streets to be treated shall be made by the Contractor and the Director or his / her Designee prior to beginning work . 2 . MATERIALS 2 . 1 Asphalt Cement Asphalt cement for the asphalt - rubber mixture shall be PG 58 - 28 OR PG 64 - 28 , complying with the requirements of appropriate state or local specifications . The grade selected shall be based on laboratory testing by the asphalt - rubber supplier . 2 . 2 Anti - stripping Agent If required by the job - mix formula to produce appropriate water resistance , an antistripping agent that is heat stable and approved for use by the Agency shall be incorporated into the asphalt - rubber material at the dosage required by the job - mix formula ( up to 1 . 0 % by weight of asphalt ). It shall be added to the asphalt cement prior to blending with the granulated rubber . 2 . 3 Rubber The granulated rubber shall be vulcanized rubber product from the ambient temperature processing of scrap , pneumatic tires . The granulated rubber shall meet the following gradations : No substitutions will be accepted . Sieve Size % Passing 2 . 00 mm , (# 10 ) 100 1 . 18 mm , (# 16 ) 90 – 100 0 . 60 mm , (# 30 ) 25 – 75 0 . 18 mm , (# 80 ) 0 - 20 The use of rubber of multiple types from multiple sources is acceptable provided that the overall blend of rubber meets the gradation requirements . The length of the individual rubber particles shall not exceed 3 mm , ( 1 / 8 ”). The rubber shall be accepted by certification from the rubber supplier . 2 . 4 Aggregate The aggregate shall conform to the requirement of appropriate state or local specifications for crushed stone . Crushed gravel stone will not be permitted . Percentage of wear as determined by the Los Angeles Abrasion Test ( AASHTO - T96 ) shall be a maximum of 30 . The aggregate shall be pre - heated to a temperature between 93  C and 149  C , ( 200  F and 300  F ), and be pre - coated with 0 . 4 % to 0 . 8 % ( by weight of aggregate ) of AC - 10 or AC - 20 asphalt cement prior to application . It is recommended that the gradation of the aggregate meet the following limits : Sieve Size % Passing – Nominal Size 9 . 5 mm , ( 3 / 8 ”) 12 . 5 mm , ( 1 / 2 ”) 15 . 8 mm , ( 5 / 8 ”) 100 % 100 % 12 . 5 mm , ( 1 / 2 ”) 100 % 85 – 100 % 9 . 5 mm , ( 3 / 8 ” 85 – 100 % 15 – 45 % 4 . 75 mm , (# 4 ) 0 – 25 % 0 – 15 % 2 . 36 mm , (# 8 ) 0 – 5 % 0 – 5 % 0 . 30 mm , (# 50 ) 0 – 2 % 0 – 2 % 0 . 075 mm , (# 200 ) 0 – 2 % 0 – 2 % 2 . 5 Materials Testing A minimum of 60 days prior to construction the Agency or contractor ( if asphalt - rubber supplier is acting as a sub - contractor ) shall send a representative sample of the asphalt cement and the aggregate proposed for use to the asphalt - rubber supplier for testing . Testing for stripping and asphalt content to determine and assure that appropriate characteristics are achieved when blended with the granulated rubber will be performed . All costs for testing are to be incidental to the work and borne by the contractor . A copy of all test results shall be submitted to the Awarding Authority . 3 . ASPHALT - RUBBER MIXING AND REACTION 3 . 1 Mixing and Reaction The percent of rubber shall be 20 +/- 3 % as indicated by the mixture design for specific project requirements by weight of total mixture , that is , by total weight of asphalt cement , plus granulated rubber . The exact granulated rubber content shall be determined by the mix design submitted by the asphalt - rubber supplier based on laboratory testing . The temperature of the asphalt shall be between 177  C and 218  C , ( 350  F and 425  F ), at the time of addition of the granulated reclaimed rubber . The asphalt and rubber shall be combined and mixed together in a blender unit and reacted in the distributor for a period of time as required by the mix design . The temperature of the asphalt - rubber mixture shall be above 163  C , ( 325  F ), during the reaction period .

Massachusetts

2026-05-03