Abstract:
This disclosure relates to pavement systems and methods for paving that 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.
Abstract:
The co-polymer soil subgrade binder relates to compositions utilizing ionic polyampholyte co-polymers in combination with soil to form improved subgrade soil binder compositions for supporting roads and pavement surfaces. The binders were aqueous solutions of three synthetic ionic variations of polyacrylamide: cationic poly(acrylamidopropyl trimethyl ammonium chloride), anionic hydrolyzed poly(acrylamide) and the ampholytic terpolymer poly(acrylamide- co-sodium acrylate-co-(3-acrylamidopropyl) trimethylammonium chloride). Mechanical testing of soil samples showed that a 50% aqueous solution of the ampholytic terpolymer (TPAM) gives the best properties in terms of strength and toughness. Also, the use of this ampholytic terpolymer gave better soil mechanical properties than the traditional standard, Portland cement under equivalent conditions.
Abstract:
A soil structure, for example a roadbed or levy, is made by admixing into soil from the course of the soil structure (a) calcium oxide, (b) at least one of cement kiln dust, lime kiln dust, fly ash, or cement, (c) a polymer binder for soil that is substantially gravelly, or liquid glass if the soil contains substantial quantities of pozzolanic material, and (d) water. The admixed soil is compacted into a roadbed or other soil structure of predetermined dimensions. After a predetermined amount of time, the liquid sodium metasilicate will catalyze hardening of the admixture if the soil contains sands or substantial quantities of pozzolans, otherwise the binder will cause hardening of the soil.
Abstract:
A method is provided of stabilizing roadbed material containing at least 2% by weight clay comprising adding to the roadbed material potassium formate in an amount effective to enhance stability thereof. A water-soluble polymer is preferably added to the roadbed material, which polymer is preferably a cationic polymer.
Abstract:
A perforated geocell is made from a plurality of strips that form cells. Each cell wall has a single pattern of perforations spaced evenly over the cell wall. This avoids uneven distributions of stress over the cell wall, reducing deformation of the geocell.
Abstract:
본 발명은 친환경 도로 포장방법에 관한 것으로, 더욱 상세하게는 흙을 이용하여 흙 포장층을 형성하고 상기 흙 포장층의 상부에 박층의 상온 아스팔트층을 형성하여 친환경적인 도로를 건설하는 것이다. 본 발명의 친환경 도로 포장방법은 흙에 효소액을 투입한 후, 시멘트 및 무기질 첨가제를 혼합하여 흙 포장재를 준비하고, 이에 물을 혼합하는 단계와, 상기 물이 혼합된 흙 포장재를 포설하는 단계와, 상기 포설된 흙 포장재를 다짐하는 단계와, 상기 흙 포장재의 상부에 상온 아스팔트를 박층으로 포장하는 단계를 포함하여 이루어지며, 상기 무기질 첨가제는 황산알루미늄, 리그닌술폰산나트륨, 리그닌술폰산마그네슘, 트리포리인산나트륨, 염화칼륨, 염화칼슘, 염화마그네슘, 염화나트륨, 탄산칼슘 및 암모니아수를 포함하여 이루어지는 것을 특징으로 한다.
Abstract:
Provided herein are roadways containing polyurethane materials. A roadway includes a base layer of a compacted in situ material and/or a wear layer disposed on the base layer. One or both of these layers may include the polyurethane material to bind other components in the layers and to form more robust and durable roadway structures capable of withstanding operating loads of the roadway. In some embodiments, the polyurethane material is added to the wear layer by mixing in situ soil and/or foreign aggregate with polyurethane material or by dispensing the polyurethane material over the existing partially formed wear layer. The base layer may or may not include a polyurethane material. The type, concentration, distribution, and processing of the polyurethane material in the wear layer may be the same or different than that in the base layer.
Abstract:
The present invention provides dry mix compositions for use in a cement slurry comprising carboxymethyl cellulose (CMC) alone or in a blend with hydroxyethyl cellulose (HEC), one or more setting retardant, and hydraulic cement or lime wherein the carboxymethyl cellulose has a 1% solution viscosity ranging from 75 to 4400 cps measured as a 1.0 wt.% aqueous solution of the cellulose ether at 20°C, 2.55 s -1 shear rate with a Haake Rotovisko viscometer, Model 550. In addition, the present invention provides methods of forming cement stabilized substrates comprising mixing the dry mix composition and water to form a cement slurry, adding the cement slurry to a substrate, mixing the cement slurry into the substrate, and grading and compacting the mixture of substrate and cement slurry. The compositions retard setting and stabilize cement slurries in use, especially with recycled asphalt substrates.