Micro-surfacing SRF Consulting Group, Inc. SemMaterials Sponsored by: Minnesota LTAP Center Presented by: Michael Marti, P.E. SRF Consulting Group, Inc. Dan Wegman, P.E. SemMaterials The objective of this presentation is to give a basic overview of Micro-surfacing, a Koch XP micro-surfacing technology. SRF Consulting Group, Inc.

History of Micro-surfacing Developed in Europe in 1970’s Introduced in U.S. in 1980 Now used in more than 30 states Used for rut filling and texturing Micro-surfacing was developed in Europe in the 1970s and introduced in the US in 1980 in Kansas. Since then it is now used in more than 30 states. Micro-surfacing has been used for rut filling and texturing their moderate- to heavy volume roads. SRF Consulting Group, Inc.

What is Micro-surfacing? Surface treatment 3/8” to 1/2” thick Sometimes mislabeled as a polymer modified slurry seal Advantages over slurry seal are Chemical breaking process Faster curing time Can be applied at night Can be placed in a thicker layer Micro-surfacing can also be viewed as a polymer-modified cold paving slurry seal system. Micro-surfacing is different from conventional slurry seals in that it cures faster and can be placed in a thicker layer than slurry seals, and may allow a 25-40% reduction in bonder content. SRF Consulting Group, Inc.

What is Micro-surfacing? It is a mixture of Polymer modified emulsion Crushed aggregate Mineral filler Water Additive Micro-surfacing can be used on asphalt and portland concrete pavements for rut filling, to restore skid resistance, to reprofile, and to provide a wear course. SRF Consulting Group, Inc.

Micro-surfacing Paving Machine Mineral filler Crushed Aggregate Polymer-modified Emulsion, Water, and Chemical Additive Conveyor Mixer . Micro-surfacing mix Water Spraybar Spreader box SRF Consulting Group, Inc.

Micro-Surfacing Application Cement additive water Polymer Modified Emulsion Crushed aggregate Water Flows Spreader box Mixture Brown & Homogeneous Breaking Time 60 to 120 seconds Mixture Black Mixing time 15 to 45 seconds Direction Traffic in Approximately One Hour

How is Micro-surfacing used? On asphalt and concrete pavements it can fill ruts restore skid resistance address oxidized, raveled, and flushed surfaces reprofile (leveling) provides wear course be used as an interlayer Micro-surfacing can be used on asphalt and portland concrete pavements for rut filling, to restore skid resistance, to reprofile, and to provide a wear course. SRF Consulting Group, Inc.

Performance varies with... Micro-surfacing Performance varies with... Climate Traffic Existing pavement Materials / mixture design Construction quality The performance of Micro-surfacing is affected by various factors, such as climate, traffic loading, existing pavement conditions, the quality of materials and mixture design, and construction quality. SRF Consulting Group, Inc.

Condition of existing pavement Micro-surfacing Condition of existing pavement Structurally sound Moderate- and high-volume roads To achieve a successful micro-surfacing application, the existing pavement should be structurally sound. The pavement should also be stable, with no excessive irregularities or shoving. Micro-surfacing can be used on both moderate- and high-volume roads. SRF Consulting Group, Inc.

Weather conditions Air temperature at least 50°F Micro-surfacing Weather conditions Air temperature at least 50°F Pavement temperature at least 50°F No rain No freezing within 24 hours Micro-surfacing should not be placed if air or pavement temperature is below 50°F (10°C), if it is raining, or if the temperature is supposed to drop below 0°C within 24 hours of placement. Extremely hot, dry weather can cause the surface to break too fast, which will cause water retention and slow down interior curing. Hot weather requires a change in formulation to allow for extended mixing times so the micro-surfacing can be properly applied. SRF Consulting Group, Inc.

Construction considerations Micro-surfacing Construction considerations Repair / seal joints and cracks; cure Clean the surface of the road Tack coat dry or raveled surface concrete Potholes, joints, and cracks should be repaired and sealed before the application of micro-surfacing. Repairs should be allowed to cure and should not be allowed to build up on the surface. Otherwise, the sealant could be torn by the screeds during the application of micro-surfacing, leaving drags or tear marks. The road should then be cleaned. A tack coat is required if the roads are extremely dry or raveled, or if the road is concrete. SRF Consulting Group, Inc.

Micro-surfacing performance Wheel rut resistance - Excellent Skid resistance - Excellent Raveling resistance - Good Treatment for flushing - Good Interlayer - Good Resistance to reflection cracks - Low When properly designed, constructed, and used on structurally sound existing pavements, micro-surfacing generally performs well in resisting ruts for 4 to 7 years. Micro-surfacing provides excellent skid resistance and has been used by many states to address raveling with good results. Micro-surfacing, like other thin treatments and overlays, does not prevent long-term resistance to reflective cracking. Some states use micro-surfacing to address flushing on asphalt pavements. Some states report good performance from micro-surfacing as an interlayer, but this is not a standard use of this treatment. SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing 7-2 Micro-surfacing is a thin surface paving system composed of polymer-modified asphalt emulsion, 100 percent crushed aggregate, mineral filler, water, and field control additives as needed. It is applied as a thin 10-15 mm surface treatment. SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Rut Box

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.

Micro-surfacing SRF Consulting Group, Inc.