Influence of Ultrafine Natural Steatite Powder on Setting Time and Strength Development of Cement

This paper deals with the setting time and pozzolanic activity of cement when ultra fine natural steatite powder (UFNSP) is used as replacement for cement. Initial setting time, final setting time, and mortar cube strength were studied, due to the replacement of ultra fine natural steatite powder with cement at 5%, 10%, 15%, 20%, and 25% by mass of cement. The setting time of fresh cement-binder paste and compressive strength of mortar cubes are observed. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied to investigate the microstructural behaviour and chemical element distribution inside cement-binder matrix. Results indicate that the length of dormant period is shortened. The replacement of ultra fine natural steatite powder with cement reduces initial setting time, and final setting time and increases mortar cube compressive strength

An Investigation on Self-Compacting Concrete Using Ultrafine Natural Steatite Powder as Replacement to Cement

An experimental investigation was made on flow properties and compressive strength of self-compacting concrete (SCC) with ultrafine natural steatite powder (UFNSP) as replacement to cement. The tests were conducted on specimens with 5%, 10%, 15%, 20%, and 25% of replacement of UFNSP to the weight of cement and compared to the control specimens. The flow properties of all specimens were tested and checked for their limit with the existing guidelines. The compressive strength test was done on all specimens for strength of 7 days, 14 days, 28 days, and 56 days. The hardened samples were tested for their microstructural behavior and the elements Mg, Ca, and Si were mapped. Through mapping, the formations of M-S-H along with C-S-H are observed. The results show that the addition of UFNSP influences the flow property, by reducing the flow, and increases the compressive strength till 20% replacement. Further the addition of UFNSP increases the denseness of microstructure of the specimens thus resulting in the strength increment

Investigation on Calcined Magnesium-Based Mineral Powder and Its Behavior as Alternative Binder

This paper investigates the behavior of calcined powder made of natural magnesite and natural steatite. The magnesite and steatite are made into a powder of ratio 3 : 1 by weight proportion, and the combination is thermally decomposed at a temperature of 1200° Celsius. The calcined powder along with and without Sodium Tripolyphosphate (STPP) salt is tested for its microscopic structural development, consistency, initial setting time, final setting time, and heat of hydration. The powder is made into paste with water/powder ratio as 0.25 and the hardened samples are tested for its compressive strength, drying shrinkage, pH value, SEM analysis, and XRD analysis. The results show that adding phosphate salt increases the hydration process, setting time, and strength aspects. The test samples are found with hydration products such as magnesium hydroxide and struvite. Thus, the present work shows that natural metamorphic magnesite and natural metamorphic steatite can be the potential alternative resource for the production of magnesium-based binder

Ammonia free deliming process in leather industry based on eco-benign products

518-521<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">Deliming is one of the most important unit operations in leather processing. Conventional deliming process employs ammonium salts which generates considerable amount of ammonia during the process, making tannery environment unhealthy. Therefore ammonia free deliming process is necessary in view of environmental concern. Even though ammonia free alternate deliming processes have been studied earlier, they have not yet provided commercial viability so for. Hence in this paper, ammonia free deliming process based on eco-benign natural products as developed by CSIR-CLRI has been presented. Studies involve analyzing their efficiency, process parameters, quality of leather produced and to develop a viable ammonia free deliming system. The results indicate that complete deliming could be achieved using this product. Physical testing results indicate that strength properties are on par with control process and pass minimum test requirements for shoe upper leather. Organoleptic properties and overall assessments indicate that leathers delimed with CSIR-CLRI AFD are on par with that of conventional leathers. Thus, CSIR-CLRI based AFD could provide alternative system as ammonia free deliming process, which is of great environmental and safety concern.</span