Rev 8-14-97

PLANT LABORATORY FOR PLANT MIX PAVEMENTS 
401-R-324

              A laboratory shall be furnished, as a part of the plant, for the sole use of the Engineer. It shall be located so that the operation on the truck bed spraying platform and the discharging of the mixer into the trucks shall be in full view of the laboratory. The laboratory shall be in accordance with requirements (a) through (h) of 105.17. However, the floor area shall be a minimum of 15 m2 (160 sq ft). The laboratory shall also have a separate dedicated telephone line.

              Two workbenches with approximate dimensions of 1.8 m (6 ft) long by 0.9 m (3 ft) wide shall be provided. One workbench shall be 750 mm (30 in.) high. The second workbench shall be 900 mm (36 in.) high. A stand to hold an extractor shall be attached to one end of the workbench. The stand shall be approximately 0.6 m (2 ft) long by 0.9 m (3 ft) wide by 750 mm (30 in.) high. A fully enclosed exhaust fan unit with an access port shall be mounted at the end of the workbench such that the vertical centerline of the exhaust unit is at the point where the workbench and the extractor stand are attached. The exhaust fan unit shall be mounted flush with the inside wall surface. Duct work shall be built across the entire back side of the workbench to direct the exhaust flow of air and fumes, and shall extend to the vertical centerline of the fan unit. The remaining half of the fan unit shall be left open to exhaust all fumes which come off the extractor or pump.

              A sketch of the exhaust system will be furnished by district materials and tests or the Materials and Tests Division upon request.

              The exhaust unit shall be capable of exhausting a minimum of 40 m3/min (1450 cu ft/min), and shall be of a design such that it affords a safe level of protection for the operator from toxic vapors. The exhaust outlet shall be located so that it is not in the direction of the prevailing wind and does not exhaust fumes directly into an outside working area or commonly used walkway.

              At least two 110 V, 20 A outlets shall be mounted above the exhaust duct work. At least one 110 V, 20 A outlet shall be mounted next to the exhaust fan. A minimum of two 110 V, 20 A outlets shall be mounted above the 750 mm (30 in.) high workbench.

              The laboratory shall be equipped with a laboratory oven for drying mixture samples in performing the test for Quantitative Extraction of Bitumen from Bituminous Paving Mixtures. The oven shall be in accordance with the following minimum requirements. The inside dimensions shall be 650 mm (26 in.) wide by 500 mm (20 in.) high by 600 mm (24 in.) deep. There shall be two shelves, forced air circulation, ventilation to outside, and a temperature control range of ambient to 180E C (350E F) with a tolerance of " 10E C (19E F).

              The laboratory shall be equipped with a fully charged 9 kg (20 lb) dry chemical fire extinguisher with a rating of 4A 40BC. The fire extinguisher shall have a maintenance check by a qualified person at least once each year. The laboratory shall also be equipped with a fire retardant blanket approximately 1650 mm (66 in.) by 2000 mm (80 in.).

              The cost of the plant laboratory shall be included in the costs of the pay items for HMA mixtures.