DCP Investigation of Strength Increases in Polyurethane and Acrylate Treated Soils-PPT Presentation

PPT Presentation

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The demonstration evaluated polyurethane and acrylate grouts for soil improvement using mock-up injections and Dynamic Cone Penetrometer (DCP) testing. Researchers also considered grout uptake, expansion, injection behavior, and soil–grout composite properties. DCP results were used to estimate Standard Penetration Test (SPT) values, California Bearing Ratio (CBR), and bearing capacity.<br /><br />Polyurethane grout permeated silty sand under shallow, unsaturated conditions, treating soil volumes of up to five times the grout’s liquid volume. Some fracturing created thin veins of reacted grout, with permeation spreading outward from them. The injection pattern produced a relatively uniform composite. Compared with untreated soil, polyurethane-treated soil had about twice the DCP resistance, with estimated increases of 33% in SPT values, 133% in CBR, and 80% in bearing capacity.<br /><br />Acrylate-treated soil had DCP resistance similar to untreated soil, but the treated ground supported a four-foot excavation cut and remained readily excavatable. Acrylate also permeated into weaknesses in the polyurethane mass, suggesting that combined grouting could provide both soil stabilization and a water barrier.<br /><br />The results are preliminary; further laboratory testing and mock-ups are needed to establish performance and suitable applications, particularly for acrylate-treated soils.

Keywords

polyurethane grout

acrylate grout

soil improvement

Dynamic Cone Penetrometer

soil stabilization

permeation grouting

grout uptake

bearing capacity

Standard Penetration Test

California Bearing Ratio