Soil stabilization

About: Soil stabilization is a research topic. Over the lifetime, 3161 publications have been published within this topic receiving 48437 citations.

Use of secondary additives in fly ash based soil stabilization for soft subgrades

Abstract: Expansive soils are widespread in many parts of the world. Due to its low strength, high compressibility, and massive volumetric changes, these soils are a potential origin of damage to roads, buildings, foundations and other geo-infrastructure. Extensive research has been conducted on the utilisation of fly ash to stabilize expansive soils. This paper describes how the efficiency of fly ash based soil stabilization can be improved using secondary additives. Class F fly ash, an industrial by-product, was used as the base additive. Lime, CSA cement, enzyme and polymers were utilized as secondary additives. A series of mechanical and microscopic tests (CBR, compaction test, SEM, XRD, FTIR and TGA) was carried out on different combinations of additives. The results indicate that secondary additives can be effectively used to improve the efficiency of fly ash based soil stabilization. Soil-fly ash-lime-enzyme was identified as an optimum combination to enhance bearing capacity while soil-fly ash-lime and soil-fly ash-enzyme also showed substantial improvements in subgrade performance. Findings from laboratory investigations were verified applying into 3-D numerical modelling to evaluate the pavement performance which revealed substantial benefits of pavement thickness reduction when fly ash stablized weak soils are treated using secondary additives.

Comparative Effects of Hydraulic, Calcitic and Dolomitic Limes and Cement in Soil Stabilization

Abstract: The addition of lime to soils brings about changes that a re refleeted in the plasticity and strength characteristics of the soils. To study these changes, representative samples of different types of lime, hydraulic, calcitic hydrated, dolomitic monohydrate, and dolomitic dihydrate were selected. For comparison, a sample of type I cement was also used. The effects on plasticity were studied with a very heavy clay (gumbotil), and the effects on unconfined compressive strength with two fine-grained soils (friable loess a nd plastic loess). The results obtained so far indicate that there are marked differences in the plasticity and strength results, depending on the type of stabilizer used .

Strength and Durability of Cement-Treated Lateritic Soil

Abstract: The transportation infrastructure, including low-volume roads in some regions, needs to be constructed on weak ground, implying the necessity of soil stabilization. Untreated and cement-treated lateritic soil for low-volume road suitability were studied based on Malaysian standards. A series of unconfined compressive strength (UCS) tests was performed for four cement doses (3%, 6%, 9%, 12%) for different curing times. According to Malaysian standards, the study suggested 6% cement and 7 days curing time as the optimum cement dosage and curing time, respectively, based on their 0.8 MPa UCS values. The durability test indicated that the specimens treated with 3% cement collapsed directly upon soaking in water. Although the UCS of 6% cement-treated specimens decreased against wetting–drying (WD) cycles, the minimum threshold based on Malaysian standards was still maintained against 15 WD cycles. On the contrary, the durability of specimens treated with 9% and 12% cement represented a UCS increase against WD cycles. FESEM results indicated the formation of calcium aluminate hydrate (CAH), calcium silicate hydrate (CSH), and calcium aluminosilicate hydrate (CASH) as well as shrinking of pore size when untreated soil was mixed with cement. The formation of gels (CAH, CSH, CASH) and decreasing pore size could be clarified by EDX results in which the increase in cement content increased calcium.

Geophysical use of quarry dust (as admixture) as applied to soil stabilization and modification-a review

Abstract: The availability of build able land is fast drifting away each day due to scarcity of lands with good natural bearing capacity. This leads to construction of buildings on poor soils which eventually lead to structural foundation failures. It has become very imperative to improve soils or the quality of grounds by the adoption of suitable improvement methods depending on the materials available. However, during soil or ground improvement, cost effectiveness is one of the major factors considered cardinal. Consequent upon this, there is a paramount need to adopt the use of admixtures during cement/soil improvement or stabilization. This necessitated the review on a very important admixture in geotechnical engineering and in cement stabilization of soils during pavement construction. However, quarry dust which is a waste product from aggregate production could replace some proportions of sand/soil. This admixture not only replaces some proportions of soil for cost effective soil improvement but according researches carried over the years on this waste product, improves the geophysical properties of the joint mixture; cement/soil/quarry dust. Since the introduction of quarry dust improves the engineering behavior of soils, this review work exposes those qualities and applications that make quarry dust a good replacement or admixture during soil improvement and for a more economic approach. The present review also gives researchers and geotechnical engineers a clue on the application of quarry dust and the limit for its usage.