Description This provision covers the micro surfacing materials, equipment, construction and application procedures for surfacing, leveling or rut filling of existing paved surfaces in accordance with the contract. The micro surfacing system shall be a mixture of cationic latex modified asphalt emulsion, mineral aggregate, mineral filler, water and other additives, properly proportioned, mixed and spread on the paved surface in accordance with this provision and as directed by the Engineer. Materials (A) Latex Modified Emulsified Asphalt The emulsified asphalt shall be a cationic type CQS-1hLM and shall conform to AASHTO M 208 or ASTM D2397. In general, 3% polymer solids, based on asphalt weight, is considered minimum. The ring and ball softening point of the residue shall be a minimum of 135°F. It shall show no separation after mixing. The cement mixing test is waived for the latex modified CQS-1hLM. (B) Mineral Aggregate The mineral aggregate used shall be compatible with the latex modified emulsified asphalt and can produce a good skid resistant surface. The aggregate shall meet requirements in Article 1012-1 of the Standard Specifications. (C) Mineral Filler Mineral filler shall be any recognized brand of non-air entrained Portland cement that is free of lumps or hydrated lime meeting the requirements of ASTM D242. It may be accepted upon visual inspection. (D) Water The water shall be potable and shall be free of harmful soluble salts in accordance with Article 1024-4 of the Standard Specifications. (E) Latex Modifier A latex based modifier, certified from an approved source, along with special emulsifiers shall be milled into the asphalt emulsion by an approved emulsion manufacturer. (F) Other Additives The additives are any other materials that are added to the emulsion mix or to any of the component materials to provide the specified properties. The additives shall be supplied by the emulsion manufacturer to provide control of the set time in the field. Mix Design The Contractor is required to design the asphalt mix and to obtain an approved Job Mix Formula (JMF) issued by the Department. A mix design and proposed JMF targets for each required mix type and combination of aggregates must be submitted in electronic format to the Materials and Tests Unit for review and approval at least 10 days prior to start of asphalt mix production. The mix design shall conform to the International Slurry Surfacing Association’s ISSA A143, Section 5.2.
