Volume 08 Issue 01
Review Study on Properties of Nanocomposite Materials for Aerospace Applications
Ankit Kumar Mishra, J. V. Muruga Lal Jeyan | pp: 01-07 | Download Paper | Show Abstract
Abstract: The polymeric nanomaterials play an important role in aerospace industry for different parts to be used in aircrafts, bombers and space launch vehicles. These materials have higher tensile strengths as compared to other materials on macro as well as micro levels. Poly-composite nanomaterials involve nano fillers isolated in it for better adhesive properties. This review paper deals with the study of properties such as weight reduction, thermal characteristics, electronic properties and impact toughness that are responsible for nanocomposites to resist at alternative operating conditions for structural arrangements and performances. The properties of materials depend on several factors such as thermal conductivity, glass transition temperature, strengths, resistance etc. that are responsible for the variation in composite matrices.
Performance of Cement Grouts and their Applications
Yogita Gaude, K. G. Guptha, T. Mohan | pp: 08-14 | Download Paper | Show Abstract
Abstract: Cement grouts are extensively used in many of the construction areas such as coatings for prestressing strands/tendons, repair, and rehabilitation of masonry and RCC structures, grouting of soil, etc. They comprise a fluid mixture of cement, sand if used, water, and possibly, admixture(s) along with non-shrink additives. They are commonly used because such grouts possess higher compressive strength. Their rheology and properties can be easily modified by varying the mix proportions and dosages of the various components. Cement grouting is used on large-scale applications for grouting of cable ducts of prestressed bridges to fill in the voids or gaps between ducts and prestressing steel. These structures are vulnerable to deteriorations and damages such as strength and durability losses which occur due to corrosion and breaking of prestressing tendons/strands resulting from inadequate grouting and/or chloride attacks from airborne salts, use of deicing salts, or even the use of sea sand in the concrete. Therefore, it is very much essential that this passive layer i.e. grout should be properly mixed and grouting should be carried out with utmost precautions. Proper material proportioning, mixing and placement is a must so that grout can fulfill the required properties after hardening. Pure cement grout bleeds thus lowering the w/c ratio but increasing strength. Thus, to improve its rheological properties like bleeding, shrinkage, strength, certain admixtures like Cebex 100, Cebex 200 and Cebex EN or equivalent will be added and their properties will be evaluated. This research intends to investigate the performance of cementitious grouts based on dosage and other additives at a major River Bridge Project in Goa.
Effects of Ferrous ion as Impurity in Mix-Water on the Setting Time of Oilwell Cement Slurry in High-Pressure, and High-Temperature Environment
Sunday Igbani | pp: 15-26 | Download Paper | Show Abstract
Abstract: The effects of heavy metals in mix-water on the setting time of cement slurries have been investigated, to design acceptable ST of cement slurries; but, still there are reported cases of cement slurry ST failures. This may be as a result of the exclusion, of investigating the impact of ferrous ion in mix-water on setting time. Consequently, this research paper investigated the effects of ferrous ion as impurity in mix-water on the ST of slurries in high-pressure, and high-temperature environment. To accomplish this, sampled mix-water from the study area, Kolo Creek, were subjected to water analysis, using the American public health association drinking water test methods. The results revealed that, ferrous ion in high concentration was found presence in each of the mix-waters, when compared with the world health organisation threshold. These mix-waters were used to formulate slurries of 0.44 water-to-cement ratio. These slurries were subjected to ST tests using the CEMSET approach. In general, the results demonstrated that, high concentration of ferrous ion in mix-water, with the collaborating synergistic effects of HPHT accelerated the ST, which makes the cement slurry, to set-faster. This suggest that high concentration of ferrous ion induced the exothermic reaction of C3A during hydration.