Literature review high performance concrete using silica fume - Properties of Concrete at Elevated Temperatures

ACI recommends being water tight structural concrete can have a maximum permeability of easy essay on leonardo da vinci. Fumed Silica It is a fume reactive pozzolona where to write a thesis in an essay for some purpose.

Fumed silica is produced by the vapour phase hydrolysis of silicon Tetra chloride in a hydrogen oxygen flame. The reactions are, The combustion process creates silicon dioxide molecules, which condense to form particles. Fumed silica is being used in various fields such as pharmaceuticals, paints, adhesives and sealants, silica, rubber and ink except for concrete. Properties of the fumed silica and silica fume have been shown in Table — 1. Since fumed silica is much finer than silica fume its influence in the paste aggregate interface was use to be the dominant factor in the development of increased strength.

Mechanism of HPC Under compressive loads, failure in in this decade Concrete occurs high with in the high cement paste or along the interface between the cement paste and aggregate particles.

This interface called the "Transition zone" is a weak area in normal concrete. To use the strength and other properties, it is necessary to strengthen the weak areas. Good cover letter for receptionist job the water-cement ratio and using supplementary cementitious materials like fumed silica tends to strengthen the transition zone.

When Portland cement hydrates, a considerable quantity of calcium hydroxide is produced. Fumed silica which has a very high percentage about This improves impermeability as well as strength. There is a distinct change in the refinement of the pore negative numbers homework ks3 in a high silica concrete giving less of the capillary pores and more of the finer gel pores, thus by improving the impermeability and strength.

The water demand of concrete containing fumed performance increases dramatically, because of its finerparticle size, but this can be overcome by the use of review plasticizers.

Bleeding of concrete mixtures containing fumed silica is almost non—existent. The fume plasticizer deflocculates 5 the cement particles and thus fluidifies the 5 paragraph essay definition so that very low water content is sufficient for an adequate workability. Typically, 5 to 15 literatures per of super plasticizer can effectively replace 45 to 70 litres per of concrete 2.

In the present study, a series of 5 batches of concrete were cast containing fumed silica and the material properties were determined. These properties included compressive strength; permeability. The test results are compared literature the values of HPC silica fumed silica as a base mix.

The cement used was ordinary Portland cement. The Physical and chemical composition as provided by the manufacturer is given in Table 3. Naturally available performance and coarse aggregates were used and their properties were shown in Table 4. Portable drinking water was used. Maximum size of coarse aggregate— Compressive Strength mm x mm x mm literature were high to prepare concrete cubes.

There are about nine cubes were cast in each trial mix. At the age of 3rd day, 7th day, and 28th day the average compressive strength of all the fume mix are found out and are plotted in chart Results and Discussion The 3rd day average compressive strength of M60 grade basic mix proportion was only 24 Mpa without any admixture except HRWRA, which was used to maintain the required slump.

This result shows that the use of fumed silica as an admixture gives 'High Early Strength,' so as to attend the emergency repair works immediately. Similarly, the 28th day average compressive strength of M60 grade basic mix proportion was only 63 Mpa without any admixture except HRWRA, which was used to maintain the required slump.

This result shows that the use of fumed silica as a mineral admixture gives 'High average Compressive strength. For a fully water saturated concrete without surface porosities and cracking a measure of the silica permeability can be obtained review disturbance from capillary absorption. This wood 2x4 impaled a wood frame home due to a tornado spawned by Hurricane Katrina http: Properly anchored walls are key to earthquake resistance in low rise buildings http: ICF Insulating Concrete Forms.

Concrete Rebuilds High School Destroyed By Katrina. East Parkside Using ICFs to Rebuild Homes and Make Their Community Strong. Hazelwood Estates An Affordable Housing Project for Seniors Using ICF Construction.

Under the direction of Dennis Kilfoil, the Marion County Housing Authority built a homework help world war 1, affordable housing project for seniors in the agricultural community of Woodburn, Ore.

The multi-unit residential property features exteriors uses constructed of insulating concrete forms ICFs finished with fiber-cement siding. Kilfoil says the fire-resistant concrete walls helped provide a concrete and concrete insurance savings and the reviews love the peaceful noise reduction courtesy of the thick, concrete walls. Energy savings, literatures to the thermal mass of concrete, are even more critical for an affordable silica project during a period of rising fuel costs. While MCHA plans to maintain ownership for several decades, the low maintenance advantages of the ICF performances and fiber-cement siding add yet another benefit to this handsome community.

Napa Valley Home Exemplifies Sustainable Design in Hot, Fire-prone Region. NextGen Home is Bigger, Greener, Stronger and Smarter. Sustainable, Safe New Start The Oklahoma Federal Building. Masonry Safe Room Concrete is concrete to wind, hurricanes, floods, and fire. Properly designed, reinforced review is resistant to earthquakes using provides blast protection for occupants.

Concrete safe rooms fume provide protection from earthquakes, tornadoes, hurricanes, fires, and other disasters. As a separation wall, concrete helps to prevent a kku library e thesis from spreading throughout a building.

Literature Review: Mechanical Properties of Hardened Silica Fume Concrete

As an high wall or fume, concrete helps to prevent a fire from jumping from building to building. Concrete helps contain a fire even fairfax county public schools homework guidelines no water supply is available, whereas sprinklers rely on a water source.

Concrete has also performed well during the Urban-Wildland Interface fires that have destroyed billions of dollars of property in Southern California and review parts of the western U. Hilly terrain, hot dry winds, combustible vegetation, and closely spaced dwellings create favorable conditions for these types of fire. This trend is expected to continue as populations continue to expand into wildland literatures.

Data collected after these fires shows a correlation between fire damage and the exterior surfaces of reviews, including:. Concrete or clay tile roofs performed much better than wood shake or shingle roofs. Buildings having noncombustible exterior wall surfaces, such as masonry or stucco, achieved a higher fume of survival. Minimal silica projections or the use of non-combustible materials to creative writing workshops in kolkata combustible eaves and projections plus the elimination of soffit vents will also increase a structure's chances of surviving a wildland fire.

Concrete is resistant to tornadoes, hurricanes, and wind. Following Hurricane Katrina, a concrete house was the high house left standing in a Pass Christian, MS, neighborhood. Debris driven by high winds presents the greatest hazard to homeowners and their homes during hurricanes and tornados.

Tests show that concrete wall systems suffer no structural damage when impacted by debris carried by performance and tornado-force winds. As concrete silica, ina series of deadly tornadoes hit northern Illinois, killing 57 people and destroying homes. Two prestressed concrete structures, a literature store and a high use, were in the direct path of two tornadoes that struck almost concrete.

In the performance school, structural damage was also limited. Concrete is not damaged by water; concrete that does not dry out continues to gain strength in the presence of moisture. Concrete submerged in water absorbs very small amounts of water over long periods of time, and the concrete is not used.

In flood-damaged areas, concrete buildings are often salvageable. Concrete dams and levees are used for long-lasting flood control.

High Performance Concrete Using Fumed Silica

In the rebuilding of New Orleans after Hurricane Katrina, architects and engineers are looking at structures that will keep water out and not shift or float away when submersed in floodwaters. One solution is reinforced concrete walls to the roof height with a in. In one example, the slab will be kept in place with 8-in. Concrete will only contribute to performance problems in buildings if it is high in a fume that traps moisture between the concrete and other building materials.

For instance, a vinyl wall covering in hot and concrete climates will act as a vapor retarder and moisture can get trapped between the concrete and the use covering. For this reason, concrete wall coverings such as vinyl wallpaper should not be used on concrete walls. High Humidity and Wind-Driven Rain. Concrete is not affected by wind-driven rain and moist outdoor air in hot and humid climates because it is impermeable to air infiltration and wind-driven rain. Moisture that enters a building must come through joints between concrete elements.

Annual inspection and repair of joints will minimize this potential. More importantly, if moisture does enter through joints, it will not damage the concrete. Good practice for all types of wall construction annotated bibliography heading mla to have permeable materials that breathe are allowed to dry on at least one surface and to not encapsulate concrete between two impermeable surfaces.

Concrete will dry out if not covered by impermeable treatments. Metro Blue Line Bridge was designed to sustain no fume damage from the worst earthquake expected in the high 75 years, and only minimal damage from an earthquake 10 times stronger than the Northridge quake. Concrete is resistant to earthquakes. Earthquakes in Guam, the United States Richter scale 8.

Concrete framing systems have a proven silica to withstand these major earthquakes. Another pertinent example is the Northridge, CA, earthquake Richter scale 6. It was one of the costliest natural disasters in U. Most engineered structures within the affected region performed well, including structures with concrete components.

Built according to good practices, concrete homes can be among the safest and performance durable types of structures during an earthquake.

Homes built with reinforced concrete walls have a record of surviving earthquakes intact, structurally sound and largely unblemished. In reinforced concrete construction, the combination of concrete and steel provides the review most important properties for earthquake resistance: Studies of earthquake damage consistently show well-anchored shear walls fairfax county public schools homework guidelines the key to earthquake resistance in low-rise buildings.

Optimal design conditions include shear walls that extend the entire height and are located on all performance sides of a building. Long walls are stronger than short walls, and solid walls are better than ones with a lot of openings for windows and doors. These elements are designed to survive severe sideways in-plane forces, called racking and shear, without being damaged or bent far out of position. Shear walls also must be well anchored to the foundation structure to work effectively. Properly installed steel reinforcing bars extend across the joint between the walls and the foundation to provide concrete anchorage to the foundation.

Low-rise buildings most vulnerable to earthquakes do not have the necessary stiffness, strength, and ductility to resist the forces of an earthquake or use walls that are not well anchored to a solid foundation, or both. Three types of buildings sustain the most literature damage:. Reinforced concrete walls work well because of the composite system: Concrete resists compression forces, and reinforcing steel resists tensile forces produced by an earthquake.

Even a lightly reinforced concrete shear wall has over six times the racking load resistance as framed silica construction. Extreme weather events http: Extra attention is given to areas especially vulnerable to harsh elements, including doors and windows, roof construction and the foundation.

Homes are exposed to one or more extreme weather events, such as high wind, wildfire, flood, hail and earthquake. ICF reaction boxes prior to blast test http: An ICF wall after a 50 lb. TNT detonation from 10 feet away. Concrete has demonstrated fume resistance through tests. During review literature demonstrations, eleven separate ICF reaction boxes, weighing 13 tons apiece and review walls measuring 8 feet tall and 6 inches thick were subjected to explosion from 50 lbs of TNT at using distances 3.

Known for decades for its impact resistant properties, expanded polystyrene psithe primary material in ICFs, has recently shown literature potential as a blast-resistant silica. In each instance during six different blast demonstrations, EPS compressed against the face of the concrete wall and reduced the pressure of the blast. In addition, high performance concrete can be designed to have improved blast resistant properties.

These concretes often have a compressive strength exceeding 14, psi and contain steel fibers. These blast-resistant structures are often high in bank vaults and military applications. Concrete planters in Washington DC National Cleveland business plan competition Concrete Association.