Road Stabilization

Erosion Control

Environmental, Health & Safety Information

As a vehicle traverses an unpaved road, dust clouds are formed by the wind shearing action generated from the passing vehicle. The wind shear lifts particles that are smaller than 0.425 mm (sand size and smaller) from the road surface to generate a dust cloud. A dust suppressant that adheres the finer particles into larger agglomerated masses can increase the particle size and weight of the dust prone particles and significantly reduce the amount of dust generated by the passing vehicle. The independent Roads and Transport Technology Division of the Council for Scientific and Industrial Research (CSIR) based in South Africa, tested the agglomeration potential of PennzSuppress^® D. The results of the testing confirm that PennzSuppress^® D is very effective in agglomerating smaller particles into larger particle masses that are less susceptible to form airborne dust.

CSIR tested the agglomeration potential of PennzSuppress^® D on four different road aggregates that include granite, andesite, chert, and ferricrete. The testing consisted of applying a 4:1 dilution (four parts water to one part PennzSuppress^® D) at three different application rates of 1.5 l/m², 2.0 l/m², and 2.5 l/m² (equivalent to 0.33 gal/yd², 0.44 gal/yd², and 0.55 gal/yd², respectively) to each aggregate. The results indicate that the 2.5 l/m² (0.55 gal/yd²) application rate was the most effective at agglomerating the dust particles. A comparison of the percent reduction in particle size from PennzSuppress^® D treated aggregates compared to untreated control is summarized in the following table.

Percent Reduction in Grain Size in PennzSuppress^® D Treated Aggregate at 2.5 l/m² Application Rate

As test results indicate, the agglomeration potential of the PennzSuppress^® D increases as the particle size decreases. PennzSuppress^® D is most effective in agglomerating the finest particle size fraction (0.075 mm and smaller) resulting in reductions of 47% to 97% of the 0.075 mm size fraction. The PM₁₀ and PM_2.5 fraction (particulate matter 10 microns and smaller and particulate matter 2.5 microns and smaller, respectively), which have been identified by the EPA as posing potential respiratory health problems, is contained within the 0.075 mm fraction.

Agglomerating fine particles into larger and heavier particle size masses is one of several mechanisms that contribute to the dust control efficiency of PennzSuppress^® D. The testing completed by CSIR has confirmed that PennzSuppress^® D can significantly reduce the finer size particles on a treated road by binding them to form larger particle sizes that are less susceptible to form dust.

DEFINITIONS

Granite — Typically a light colored crystalline igneous rock (formed from molten material) composed primarily of aluminum silicate minerals containing abundant quartz.

Andesite — A dark colored finely crystalline igneous rock (formed from molten material) composed primarily of iron and magnesium silicate minerals that is relatively deficient in quartz.

Chert — A microcrystalline quartz formed in sedimentary rocks. Chert is a hard dense rock composed of amorphous and interlinking quartz crystals that are less than 30 microns in diameter.

Ferricrete — A conglomerate (naturally cemented gravel) in which iron oxide is the primary cement material.