205.01 118 The Department will pay for the subgrade compaction in areas requiring excavation and replacement in 204.04, 204.05, and 204.07. The Department will not pay for subgrade compaction in areas stab ilized under Item 206. The Department will pay for accepted quantities at the contract prices as follows: Item Unit Description 204 Square Yard Subgrade Compaction (Square Meter) 204 Hour Proof Rolling 204 Cubic Yard Excavation of Subgrade (Cubic Meter ) 204 Cubic Yard Embankment (Cubic Meter) 204 Cubic Yard Granular Embankment (Cubic Meter) 204 Cubic Yard Granular Material Type ___ (Cubic Meter) 204 Square Yard Geotextile Fabric (Square Meter) 204 Square Yard Geogrid (Square Meter) ITEM 205 CHEMICALLY STABILIZE D EMBANKMENT
205.01 Description
205.02 Materials
205.03 Submittals
205.04 Construction
205.05 Mixture Design for Chemically Stabilized Soils
205.06 Method of Measurement
205.07 Basis of Payment
205.01 Description. This work consists of constructing a chemically stabilized
embankment by mixing cement or lime into the embankment soil using the method for the specified chemical. The Contract Documents include an estimated quantity for the specified chemical.
205.02 Materials. Furnish mater ials conforming to:
Portland cement ................................ ...................... 701.04 Lime (quick lime) ................................ ................ 712.04.B Furnish water conforming to 499.02. Furnish suitable natural soil, from on or off the project site, conforming to 703.16 and 203.03.
205.03 Submittals. Submit, for the Engineer’s accept ance, a report that lists the
type of equipment to be used, speed of the intended equipment usage, rate of application of the chemical, and calculations that demonstrate how the required 205.04 119 percentage of chemical will be applied. Submit the report to the Engi neer for acceptance at least 2 workdays before the stabilization work begins. If the pay item for Mixture Design for Chemically Stabilized Soils is included in the Contract Documents, prepare and submit reports according to Supplement 1120.
205.04 Construc tion. Perform chemically stabilized embankment work when
the air temperature is 40 F (5 C) or above and when the soil is not frozen. Do not perform this work during wet or unsuitable weather. Drain and maintain the work according to 203.04.A.
A.Spreading. If the pay item for Mixture Design for Chemically Stabilized Soils is not included in the Contract Documents, use the following spreading percentage rate for the specified chemical. The percentage is based on a dry density for soil of 115 pounds per cubic foot ( 1840 kg/m3): TABLE 205.04 -1 Chemical Spreading Rate Cement 5 % Lime 5 % Spread the chemical uniformly on the surface using a mechanical spreader at the approved rate and at a constant slow rate of speed. Use a distribution bar with a maximum height of 3 feet (1 meter) above the ground surface. Use a canvas shroud that surrounds the distribution bar and extends to the ground surface. Minimize dusting when spreading the chemical. Control dust according to
107.19 Do not spread chemical when wind conditions create blowing dust that
exceeds the limits in 107.19. Do not spread the chemical on standing water.
B.Mixing. Immediately after spreading the chemical, mix the soil and chemical by using a power driven rotary type mixer. If necessary, add water to bring the mixed material to between 2 and 4 percent above optimum moisture content for cement, and to at least 3 percent above optimum moisture content for lime. Continue mixing until the chemical is thoroughly incorporated into the soil, all soil clods are reduced to a maximum size of 2 inches (50 mm), and the mixture is a uniform color. For areas not under pavements or paved shoulders, the Contractor may use a spring tooth or disk harrow in place of the power -driven rotary type mixer by modifying the above procedure as follows:
1.Open the soil with a spring tooth or disc harrow before spreading.
2.Spread the chemical.
3.Use a minimum disc harrow coverage of ten passes in one direction and ten passes in the perpendicular direction to thoroughly incorporate the chemical into the soil. Continue mixing until all soil clods are reduced to a maximum size of 1 inch (25 mm) and the mixture is a uniform color.
Source: Ohio Construction and Material Specifications, 2019 Edition. Pages 0–0 of 928.