Suitability of Flyash-Lime-Phosphogypsum Composite in Road Pavements

The paper presents the suitability of flyash-limephosphogypsum composite for its use in road pavements. The content of lime and phosphogypsum was varied from 2 to 10% and 0.5 to 4% respectively in flyash. The specimen prepared was cured for 7, 28, 56 and 90 days with burlap method of curing. Compaction tests were conducted on different flyash-lime-phosphogypsum composite and these results were used for casting cylindrical specimens for unconfined compressive strength, split tensile strength, slake durability and for determination of bearing ratio. It has been concluded that flyash-lime-phosphogypsum composite satisfy the unconfined compressive strength, split tensile strength, slake durability criteria as well as giving higher bearing ratio values at 28 days of curing. Good agreement is observed between the experimental values and predicted values for tensile strength, bearing ratio, slake durability indices. The developed models will be useful for making preliminary estimate of these parameters by the field engineers for planning purposes. The empirical models presented are based on the experimental data within the range of parameter (curing period 7 to 90 days) and materials tested. Beyond this range of values the model may be checked with experimental results. The models reported in literature under estimate the properties like bearing ratio, tensile strength and slake durability indices determined from the unconfined compressive strength. The flyash-lime-phosphogypsum composite (flyash + 8% lime + 2% phosphogypsum) cured for 28 days can be used as a base/subbase course material in road pavements

Unconfined Compressive Strength of Bentonite - Lime-Phosphogypsum Mixture Reinforced with Sisal Fibers

This paper presents the effect of sisal fibers on the unconfined compressive strength of bentonite. The present study is aimed at determining the behavior of bentonite-lime-phosphogypsum reinforced with sisal fibers in a random manner. The sisal fiber content was varied from 0.5 to 2 %. The results indicated that the unconfined compressive strength of bentonite can be increased by the addition of lime, phosphogypsum and sisal fibers. The increase in unconfined compressive strength was highest with 8 % lime, 8 % phosphogypsum and 1 % sisal fibers. The reference mix reinforced with sisal fibers was able to bear higher strains at failure as compared to bentonite and bentonite- lime-phosphogypsum mixture. With the increase in sisal fiber content (0.5 to 2 %) in reference mix, there was an increase in the unconfined compressive strength. The bentonite - lime-phosphogypsum-sisal fiber mixture will boost the construction of temporary roads on such problematic soils. Further, its use will also provide environmental motivation for providing a means of consuming large quantities of phosphogypsum and natural fibers

Potential of Bentonite-lime-mix Modified with Phosphogypsum and Reinforced with Sisal Fibres

The paper presents the potential of bentonite-limephosphogypsum mix reinforced with sisal fibre in effectively reducing the pavement thickness in an extremely problematic sub-soil condition intended for road construction. In view of which, compaction, unconfined compressive strength and California bearing ratio tests were conducted. The content of lime, phosphogypsum and sisal fibre was varied from 0 to 10%, 0 to 10% and 0 to 2% respectively. The specimens were prepared at their respective optimum moisture content and maximum dry unit weight for conducting the unconfined compressive strength and bearing ratio tests and were cured for 3 to 28 days. The results of this study reveal that the unconfined compressive strength and bearing ratio of the bentonite-lime-phosphogypsum mix increased with the increase in curing period. Addition of sisal fibres to the bentonite-limephosphogypsum mix changes the behaviour of the composite from brittle to ductile in the post peak region. Scanning electron micrographs and energy-dispersive X-ray analysis confirms the improvement in unconfined compressive strength and bearing ratio. The improved behaviour of the composite indicates that the sisal fibres have the potential for use in road pavements

Embolization of Cyanoacrylate glue in systemic circulation in a case of hepatocellular carcinoma: an autopsy report

We report a case of embolism of the sclerosant dye with subsequent formation of foreign-body giant cell reaction within the veins of pulmonary and portal circulation in an autopsy case of hepatocellular carcinoma developing over an underlying primary biliary cirrhosis

Prospective observational study of vancomycin injection in SLED patient of ethnic Indians

As the Vancomycin is itself a nephrotoxic antibiotics, so it is sometime recommended to the Slow-low Efficiency Dialysis (SLED) patients against highly resisted infection. In this case, the dose monitoring is strictly maintained after Intravenous injection. The collected blood was analyzed for its concentration in HPLC for 11 patients and the half life was evaluated to study Therapeutic drug monitoring. The T1/2 of evaluated vancomycin is 39.12+ 6.81 hrs. The mean of the systemic clearance is 16.91+6.99 and mean Vd is 0.57+ 0.147. Comparatively the reported study of Mean + SD of half-life, volume of distribution, and systemic clearance were 43.1 + 21.6 hours, 0.84 L/kg + 0.17 L/kg, and 24.3 mL/min + 8.39 mL/min respectively. Thus the t-test of the means was 0.5828, degree of freedom (df) was 20, standard error of difference was 6.829 and so, the two-tailed P value is 0.5665 i.e. P > 0.5. In ethnic Indian SLED patients, T1/2 of mean + SD of 39.12 + 6.81 hrs was compared to the Caucasian patients i.e, 43.1 + 21.6 hrs. And the t-test and P-value is 0.5828 & 0.5665 respectively. Thus it was concluded that the half-life of ethnic Indian patients is less in compare to Caucasians but this difference is not so significant. The half-life of ethnic 8 patients is less than 40 out of 11 patients.Keywords: Vancomycin assay; Slow-low efficiency dialysis; Pharmacokinetic analysis; Ethnic indian

Engineering Properties of Bentonite-Lime-Phosphogypsum Composite Reinforced with Treated Sisal Fibers

The present work primarily investigates the unconfined compressive strength, the tensile load-diametral strain, the toughness characteristics and the shear strengths of bentonite-lime-phosphogypsum-treated sisal fibre composite. The unconfined compressive strengths and tensile strengths were obtained using the unconfined compressive test and indirect tensile test respectively. The results revealed that the unconfined compressive stress, the deviator stress and the tensile load at failure of bentonite-lime-phosphogypsum composite with untreated sisal fibres could be improved by the successive chemical treatment with sodium periodate, p-aminophenol and sodium hydroxide. The brittleness index and deformability index indicated a change from the brittle to ductile behavior of the bentonite-lime-phosphogypsum-untreated sisal fiber composite, with the chemical treatment

Engineering Properties of Bentonite Modified with Lime and Gypsum

This paper presents the engineering properties such as compaction, unconfined compressive strength, consistency limits, free swell index, California bearing ratio and consolidation of bentonite stabilized with lime and modified with gypsum. The content of lime and gypsum was varied from 0 to 10% and from 0.5 to 8%, respectively, to check the improvement in the engineering properties. The results of this study revealed that the dry unit weight and optimum moisture content of bentonite + 8% lime increased with the addition of 4% gypsum. The unconfined compressive strength of bentonite did not change with the increase in curing period. The unconfined compressive strength of bentonite + 8% lime increased with the addition of 4% gypsum. Beyond 4%, the unconfined compressive strength decreased. The unconfined compressive strength of bentonite-lime-gypsum mix increased with the increase in curing period. The liquid limit, plastic limit and free swell index of bentonite + 8% lime decreased; whereas the plasticity index increased with the addition of 4% gypsum. The California bearing ratio and modulus of subgrade reaction increased for bentonite stabilized with 8% lime and modified with 4% gypsum leading to reduction in earth work and required thickness of subgrade bentonite. The coefficient of consolidation of bentonite increased with the addition of 8% lime and did not change with the addition of 4% gypsum. The swell potential of bentonite + 8% lime increased with the addition of 4% gypsum. The improved behaviour of the bentonite-lime-gypsum mixture will boost the construction of road pavements on such problematic soils

Effect of Addition of Treated Coir Fibres on the Compression Behaviour of Clay

This paper presents the effect of treated coir fibres (15 mm in length) on the unconfined compressive strength of clay. Dry, sodium hydroxide and carbon tetrachloride–treated coir fibres were used in the study. The coir fibre content was varied from 0.4% to 1.6%. The results indicated that the unconfined compressive strength of clay and clay with dry coir fibres can be increased by treatment with carbon tetrachloride and sodium hydroxide. The increase in unconfined compressive strength was highest with carbon tetrachloride treatment. The clay reinforced with treated fibres was able to bear higher strains at failure as compared to clay and clay with dry fibres. With the increase in coir fibre content (0.4%-1.6%) in clay, there was an increase in the unconfined compressive strength. The clay with treated coir fibres can be used for making bricks for mud houses in rural India

Application of Machine Learning Technique in Predicting the Bearing Capacity of Rectangular Footing on Layered Sand under Inclined Loading

The aim of the present study is to apply machine learning technique to predict the ultimate bearing capacity of the rectangular footing on layered sand under inclined loading. For this purpose, a total 5400 data based on the finite element method for the rectangular footing on layered sand under inclined loading were collected from the literature to develop the machine learning model. The input variables chosen were the thickness ratio (0.00 to 2.00) of the upper dense sand layer, embedment ratio (0 to 2), the friction angle of upper dense (410 to 460) sand and lower loose (310 to 360) sand layer and inclination (00 to 450) of the applied load with respect to vertical. The output is the ultimate bearing capacity. Further, the impact of the individual variable on the bearing capacity was also assessed by conducting sensitivity analysis. The results reveal that, the load inclination is the major variable affecting the bearing capacity at embedment ratio 0, 1 and 2. Finally, the performance of the developed machine learning model was assessed using six assessing statistical parameters. The results reveal that the developed model was performing satisfactorily for the prediction of the ultimate bearing capacity of the rectangular footing on layered sand under inclined loading

Shear Strength Behaviour of Clay Reinforced with Treated Coir Fibres

The effect of treated coir fibres on the shear strength behaviour of clay is presented in this study. A series of consolidated undrained test were performed on soil reinforced with untreated, sodium hydroxide treated and carbon tetrachloride treated fibres. The coir fibre content was varied from 0.4% to 1.6%. The results indicated that the deviator stress at failure of the clay and clay with untreated coir fibres can be increased by treatment with carbon tetrachloride and sodium hydroxide. A significant increase was also observed in shear strength parameters of clay reinforced with coir fibres at different percentages. The two parameter dependent hyperbolic models were used for predicting the experimental results. The back predicted stressstrain curve at dierent fibre percentage was found to compare well with the experimental results. The clay reinforced with untreated/treated coir fibres has shown improved strength behaviour, it can be used for short term stability problems