Evaluation of Strength Characteristics of Crushed Glass-Soil Mixes

Soil can be modified by adding several additives and thereby improving their strength characteristics. Crushed glass is one such additive. Apart as an effective soil modification additive, the curb side glass can be beneficially utilised. Aim of the project is to evaluate the improvement in the strength characteristics of the soil after adding crushed glass. In this project crushed glass of different sizes and in varying percentages by weight are used and test are conducted to evaluate the improvement in the strength characteristics. The first step is to conduct the grain size analysis of the soil to check the percentage of fines present in it. This analysis is basically done to get an idea of the size of the crushed glass after crushing the glass in Los Angeles Abrasion machine. In this project it is decided to do following tests viz; Grain size analyses, Compaction test, California bearing ratio test, unconfined compressive strength test. It is expected that, the addition of crushed-glass to soil will improve the strength characteristics of soils having different percentage of fines

Dynamic response of latex modified concrete machine foundations

New materials in concrete constructions have been widely used to improve various properties such as impact resistance, strength and durability. Polymer modified concrete is one of the new materials which has been developed for potential application in the construction industry. This Paper describes the use of polymer latex for foundation blocks subjected to dynamic loads. Experiments were conducted using ordinary concrete and latex modified concrete footings of three different thicknesses, for three static loads at four excitation levels. Experimental results have revealed that the amplitude of resonance is reduced considerably in the latex modified concrete footings. It was also observed that the damping factor of the latex footing-soil system is considerably larger than that for ordinary concrete footings. Hence the use of latex in concrete foundations for machines may lead to more economical designs

Brevundimonas vesicularis : A Novel Bio-sorbent for Removal of Lead from Wastewater

In this study, a bacterial species which could remove lead from wastewater was isolated from lead contaminated soil prepared in the laboratory. Based on the biochemical and morphological characterization the bacteria were identified as Brevundimonas vesicularis . The biosorption potentiel of powdered dry biomass of B. vesicularis was investigated by batch adsorption experiments. It was found that, the bio-sorption capacities were significantly affected by the pH and initial concentration of the solution, bio-sorbent dosage and contact time. Batch and isothermal studies were carried out at optimum pH of 4. The rate of bio-sorption was found to be fast during the initial 10min and it reached equilibrium by 60min. Langmuir isotherm model was suitable for describing the bio-sorption of lead by B. vesicularis. The results indicated that, the dry biomass of B. vesicularis is suitable as an efficient bio-sorbent for the removal of lead from wastewater

Influence of drying on the liquid limit behaviour of a marine clay

The possible mechanisms of particle aggregation and reduction in liquid limit of the Cochin marine clay on drying are investigated. Mineralogical analysis showed the absence of halloysite in the marine specimen. Experimental results also ruled out the possibility of cementitious material being responsible for particle aggregation and reduction in clay plasticity on drying. The presence of calcium and magnesium as the predominant exchangeable ions and of a high pore salt concentration facilitates strong interparticle attraction and small particle separations; the latter leads to development of significant capillary stresses that permits an intimate contact of particles and growth of strong van der Waals' and Coulombic bonds

Dynamic response of latex modified concrete machine foundations

New materials in concrete constructions have been widely used to improve various properties such as impact resistance, strength and durability. Polymer modified concrete is one of the new materials which has been developed for potential application in the construction industry. This Paper describes the use of polymer latex for foundation blocks subjected to dynamic loads. Experiments were conducted using ordinary concrete and latex modified concrete footings of three different thicknesses, for three static loads at four excitation levels. Experimental results have revealed that the amplitude of resonance is reduced considerably in the latex modified concrete footings

Consistency limits behavior of bentonites exposed to sea water

This article examines the changes in interparticle forces brought about on prolonged contact (1 year period) of a bentonite clay with artificial seawater. The study is undertaken with the purpose of identifying the physico-chemical factors that impart a nonswetling character to smectite clays deposited in marine environments. Results show that equilibration of the bentonite clay with artificial seawater (total pore salinity ∼42gL<SUP>-1</SUP>) for a 1 year period does not lead to any mineralogical changes in the clay specimens; however, their exchangeable cation positions become prominently dominated by magnesium ions. The consistency limits of the seawater-equilibrated bentonite was determined on stepwise leaching to lower salinities. The predominance of diffuse double-layer repulsion forces in the pore salt concentration range of 42 gL<SUP>-1</SUP> to 1.1 gL<SUP>-1</SUP> caused an increase in the liquid limits of the seawater-equilibrated bentonite specimens on reducing the salinity in the corresponding range (42 gL<SUP>-1</SUP> to 1.1 gL<SUP>-1</SUP>). The attraction forces, however, prevail over the repulsion forces at salt concentrations &lt; 1.1 gL<SUP>-1</SUP> and cause a decrease in liquid limit of the clay specimens with reduction in pore salinity, which is typical of nonswelling clays. The attraction forces cause aggregation of the clay unit layers into domains that break down on sodium saturation of the clay specimens. It is inferred that the physico-chemical factors responsible for the nonswelling character of the seawater-equilibrated bentonite specimens at pore salt concentrations below 1.1 gL<SUP>-1 </SUP>are inadequate to explain the nonswelling character of smectite-rich Ariake marine clays. The lower consistency limits of the Ariake marine clays in comparison to the nonswelling character, seawater-equilibrated bentonite specimens is attributed to a relative deficiency of interparticle forces in the Ariake marine clay

Engineering behavior of uplifted Smectite-rich Cochin and Mangalore marine clays

The present study aims to assess whether the smectite-rich Cochin and Mangalore clays, which were deposited in a marine medium and subsequently uplifted, exhibit consistency limits response typical of expanding lattice or nonexpanding (fixed) lattice-type clays on artificially changing the chemical environment. The chemical and engineering behaviors of Cochin and Mangalore marine clays are also compared with those of the smectite-rich Ariake Bay marine clay from Japan. Although Cochin, Mangalore, and Ariake clays contain comparable amounts of smectite (32-45%), Ariake clay exhibits lower consistency limits and much higher ranges of liquidity indices than the Indian marine clays. The lower consistency limits of the Ariake clay are attributed to the absence of well-developed, long-range, interparticle forces associated with the clay. Also, Ariake clay exhibits a significantly large (48-714 times) decrease in undrained strength on remolding in comparison to Cochin and Mangalore clays (sensitivity ranges between 1 and 4). A preponderance of long-range, interparticle forces reflected in the high consistency limits of Cochin and Mangalore clays (wL range from 75 to 180%) combined with low natural water contents yield low liquidity indices (typically <1) and high, remolded, undrained strengths and are considered to be responsible for the low sensitivity of the Indian marine clays