413Hydrated Lime

Hydrated Lime

413.1DESCRIPTION

1 This section describes the requirements for adding dry lime to a wetted aggregate.

413.2MATERIALS

1 Provide materials in accordance with the following:

Material Subsection Hydrated Lime 820 Water 814

413.3EQUIPMENT

1 Provide a mechanical mixing device that creates a uniform and homogeneous mixture with all aggregate particles coated with hydrated lime as approved by the engineer.

2 Equip the mixing plant with facilities to weigh check samples and to calibrate gate openings and metering devices. Equip with weighing or metering devices (such as a vane feeder with a calibrated revolution counter) to determine the rate of hydrated lime introduced into the aggregate while the plant is in full operation. Do not use belt scales.

3 Use a spray bar or other approved method to wet the aggregate uniformly. Equip the plant with devices that meter the water and hydrated lime into the mixer. Interlock and synchronize the metering devices and feeders to maintain a constant rate of hydrated lime and water to the aggregate.

4 To control the daily quantity of hydrated lime added to the aggregate and to facilitate calibration of the metering devices, place the bulk storage container from which hydrated lime is metered on scales or equip with load cells to enable the accurate measurement of the remaining weight [mass] in the container at the end of each da y. Do not use strain gages.

5 Use a pug mill with a mixing chamber to mix the hydrated lime and water with the aggregate. Keep the materials in the chamber until obtaining a uniform and homogeneous mixture of lime, water, and aggregate. Do not use devices that allow the materials to drop directly through the mixing paddles.

6 Locate the pug mill to allow inspection of the mixture during mixing and after discharge from the mixer. Make the belt from the pug mill to the dryer accessible for sampling. Provide a template of the belt for taking a sample to determine moisture content.

Hydrated Lime SECTION 413

413.4CONSTRUCTION

1 Mix the hydrated lime and water with the aggregate before they enter the dryer.

2 Prior to entering the dryer, ensure the moisture content of the mixture meets the requirements in accordance with Table 401.4.13-2, Marshall and Superpave Plant Mix Properties.

413.5MEASUREMENT and PAYMENT

1 The engineer will measure Hydrated Lime by the short ton [metric ton]. Hydrated Lime incorporated in Level of Control 5 mix will not be measured directly for payment.

2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest

Hydrated Lime TON [t] 0.05 ton [0.05 t] 0.05 ton [0.05 t]