Tuesday, August 6, 2013

Basalt Fiber

The aim of this project is to use existing standards (ASTM, ASCE, CSI AASHTO, ISO) and tests to evaluate the material properties of basalt fiber products including how the basalt product materials compare to materials currently in use in terms of corrosion resistance, life span, fire, life, and safety to determine resilience, robustness, and economic feasibility as a potential substitute material.  These tests focus specifically on obtaining data for design parameters related to civil engineering and construction applications including infrastructure, marine environments, and buildings.  This is important and valuable primarily for economic reasons.  Adding a substitute good can increase the production possibility frontier without causing runaway commodity costs that co-occur with economic growth.  The runaway commodity costs are driven by growing demand and limited supply, basalt fiber is a potential substitute good/material that can fill unmet demand.  Infrastructure building will have to increase in the next few decades as ocean levels rise, coastlines are inundated, and as the functional lifespan of existing infrastructure expires.  If each city is left to fend for itself only the richest areas will be able to build infrastructure to protect their citizens due to the currently limited supply and range of materials, and the poorer areas will be forced to relocate.  Either way more will have to be built than ever before, even as past material supplies are being used up.

Basalt Fiber has hardness, ductility, thermal properties, and resistance to extreme alkaline and acidic environments which make it a potential green material that could be a substitute for a number of construction materials and commodities including, but not limited to, asbestos, steel, geo-composites, geo-textiles, carbon fiber, glass fiber, fire wool, and as an array of insulators.  Continuous basalt fiber has a breaking strength range of 3000-4840 MPa, a modulus of elasticity of 79.3-93.1 GPa, ductility greater than carbon fiber, greater functional temperature range than carbon fiber, with a greater fiber diameter that, unlike carbon fiber and asbestos, places is safely above the respiratory limit.  Basalt fiber as a reinforcing material in concrete and asphalt as a corrosion resistant reinforcement with a strength which exceeds any and all steel alloys.  Basalt fiber is also incombustible and unlike steel its tensile strength remains constant as the material is heated in excess of 1000 degrees centigrade.  Basalt fiber does not directly cause eutrophication or acidification and one Kg of basalt reinforcement is equivalent to 9.6 Kg of steel reinforcement.  Depending on the ore, exhuming one ton of iron ore will yield 30-60 pounds of iron, which must be heated at least once in the refining process and once again in the smelting of steel.  One ton of basalt yields one ton of basalt fiber and only needs to be heated once.  Basalt requires a fraction of the energy to produce an equivalent amount of reinforcement. Basalt is also more geographically available as compared to iron ore.  Basalt fiber costs less than carbon fiber, glass fiber, and steel.  Basalt fiber has attracted attention due to its strength, elasticity modulus, corrosion resistance, high temperature resistance, extended operating temperature range, low cost, and the ease with which it can be worked with.  Basalt can also be implemented in extreme alkalinity with pH up to 13-14 as well as in strong acids.Current technologies of spinning the basalt fiber using spinneret technology, blowing technology, or by being drawn through bushings under hydro static pressure.  The main problem in manufacture of basalt fiber is the gradual crystallization of the various structural molecular elements and the different temperatures at which they crystallize.  It is for this reason that the temperature control system at the outlet requires great precision in order to quickly quench the material and facilitate partial crystallization.  More research is being conducted on the production side to develop means to draw the as-spun filaments between rollers to modify the physical properties and to apply application specific surface finishes. One major difficulty with basalt and basalt fiber production is the lack of homogenization of the material across different locations and within the same quarry that can lead to defects, failures, and a loss of the mechanical properties which provide its value.  There are a number of well established means to mitigate this inherent shortcoming and subsequent failures for different applications.

One of the world's largest Basalt deposits also happens to be located in Oregon and Washington States.