A construction method for reinforcing a loess embankment by combining microbial mineralization with phosphogypsum. The method includes: (1) placing Bacillus pasteurii in a culture medium to prepare a microbial solution, and mixing urea, calcium chloride and water to prepare a cementing solution; (2) mixing a mixture, the microbial solution and water well, and adding the cementing solution and water to prepare an improving mixture; and (3) leveling and compacting an original ground; laying a geomembrane, the improving mixture and a geogrid; laying a last geomembrane on the top of the embankment after the embankment is laid, and then laying a roadbed. The method meets the improvement and construction requirements of loess embankments of high-grade highways, and reduces the stock of phosphogypsum, thereby reducing the occupation of cultivated land. The microbial improvement of the phosphogypsum achieves the immobilization of harmful elements, thereby reducing environmental pollution.

A construction method for reinforcing a loess embankment by combining microbial mineralization with phosphogypsum. The method includes: (1) placing Bacillus pasteurii in a culture medium to prepare a microbial solution, and mixing urea, calcium chloride and water to prepare a cementing solution; (2) mixing a mixture, the microbial solution and water well, and adding the cementing solution and water to prepare an improving mixture; and (3) leveling and compacting an original ground; laying a geomembrane, the improving mixture and a geogrid; laying a last geomembrane on the top of the embankment after the embankment is laid, and then laying a roadbed. The method meets the improvement and construction requirements of loess embankments of high-grade highways, and reduces the stock of phosphogypsum, thereby reducing the occupation of cultivated land. The microbial improvement of the phosphogypsum achieves the immobilization of harmful elements, thereby reducing environmental pollution.

Certain pavement systems and methods for paving are suitable for locations containing a generally weak subgrade with a California Bearing Ratio of four (4) or lower. The pavement system includes a first geogrid layer placed directly on the subgrade; a first granular layer upon the first geogrid layer, the first granular layer having a thickness of from 0.5 times to 20 times the aperture distance of the geogrid layer; a first geocell layer upon the first granular layer comprising a geocell and an infill material; and a capping layer over the geocell layer. A second geocell/geogrid layer can be placed beneath the capping layer, if desired. An optional surface layer may be applied upon the capping layer if desired. The resulting pavement system provides long-term support for pavements applied over the pavement system.

Certain pavement systems and methods for paving are suitable for locations containing a generally weak subgrade with a California Bearing Ratio of four (4) or lower. The pavement system includes a first geogrid layer placed directly on the subgrade; a first granular layer upon the first geogrid layer, the first granular layer having a thickness of from 0.5 times to 20 times the aperture distance of the geogrid layer; a first geocell layer upon the first granular layer comprising a geocell and an infill material; and a capping layer over the geocell layer. A second geocell/geogrid layer can be placed beneath the capping layer, if desired. An optional surface layer may be applied upon the capping layer if desired. The resulting pavement system provides long-term support for pavements applied over the pavement system.

A design and construction method for using modified phosphogypsum in a roadbed and slope, where the method includes preparing a phosphogypsum-containing roadbed mixture, setting moisture content of the roadbed mixture, preparing a phosphogypsum-containing slope mixture, and construction of a roadbed and slope. The preparation of the phosphogypsum-containing roadbed mixture includes 90 parts by weight of phosphogypsum and 10 parts by weight of cement, and uniformly mixed and stirred to obtain a base material mixture; and 2-4 parts by weight of sodium silicate is dissolved in water, and the obtained solution is added to the base material mixture to obtain the phosphogypsum-containing roadbed mixture. The design and construction method are simple, can satisfy roadbed strength and rebound modulus requirements, and can be widely applied to filling-deficient areas with a high yield of phosphogypsum solid wastes.

A design and construction method for using modified phosphogypsum in a roadbed and slope, where the method includes preparing a phosphogypsum-containing roadbed mixture, setting moisture content of the roadbed mixture, preparing a phosphogypsum-containing slope mixture, and construction of a roadbed and slope. The preparation of the phosphogypsum-containing roadbed mixture includes 90 parts by weight of phosphogypsum and 10 parts by weight of cement, and uniformly mixed and stirred to obtain a base material mixture; and 2-4 parts by weight of sodium silicate is dissolved in water, and the obtained solution is added to the base material mixture to obtain the phosphogypsum-containing roadbed mixture. The design and construction method are simple, can satisfy roadbed strength and rebound modulus requirements, and can be widely applied to filling-deficient areas with a high yield of phosphogypsum solid wastes.

Geocells for moderate to low load applications are disclosed here. The geocells have a cell wall thickness of from 0.25 mm to 0.95 mm. They have a wall strength of from 3500 N/m to 15000 N/m.

Geocells for moderate to low load applications are disclosed here. The geocells have a cell wall thickness of from 0.25 mm to 0.95 mm. They have a wall strength of from 3500 N/m to 15000 N/m.

Certain pavement systems and methods for paving are suitable for locations containing a generally weak subgrade with a California Bearing Ratio of four (4) or lower. The pavement system includes a first geogrid layer placed directly on the subgrade; a first granular layer upon the first geogrid layer, the first granular layer having a thickness of from 0.5 times to 20 times the aperture distance of the geogrid layer; a first geocell layer upon the first granular layer comprising a geocell and an infill material; and a capping layer over the geocell layer. A second geocell/geogrid layer can be placed beneath the capping layer, if desired. An optional surface layer may be applied upon the capping layer if desired. The resulting pavement system provides long-term support for pavements applied over the pavement system.

Certain pavement systems and methods for paving are suitable for locations containing a generally weak subgrade with a California Bearing Ratio of four (4) or lower. The pavement system includes a first geogrid layer placed directly on the subgrade; a first granular layer upon the first geogrid layer, the first granular layer having a thickness of from 0.5 times to 20 times the aperture distance of the geogrid layer; a first geocell layer upon the first granular layer comprising a geocell and an infill material; and a capping layer over the geocell layer. A second geocell/geogrid layer can be placed beneath the capping layer, if desired. An optional surface layer may be applied upon the capping layer if desired. The resulting pavement system provides long-term support for pavements applied over the pavement system.