Literature Review On Microsilica

First, concrete durable. Concrete is something that will outlive other products up to three times over (“What Makes…”). In addition to durability, concrete is efficient. Concrete can be made with byproducts from power plants, and other aspects of manufacturing. Concrete is primarily made up limestone, the most abundant material on Earth. Above all of this concrete can be recycled. Concrete can be crushed and recycled into another structure or product, reducing the need to mine the limestone for production. Concrete also allows water to pass through which reduces the chance of flash flooding, erosion, and water table depletion as compared to other materials. This is a major check in the sustainability of concrete; the conservation of soil, landscape and ecosystems. Concrete is a very green option when it comes to building

Property owners must know the basics of concrete composition in order to understand the effects of salts. Salt is an acid that lowers the pH balance of the concrete. Because it is acidic, it weakens the strength of the concrete and increases the size of the pores. This allows water and other elements to penetrate the surface. Salt

In this quotation from the author Vitruvius, he explains the process and creation of concrete, emphasizes on its durability and how it can withhold the forces of nature. This new formula had a higher silica content then before, which essentially allowed to concrete to set under water and made it stronger then before.10 Overall, the use of concrete was crucial to construction in ancient Rome because it was extremely durable compared to other materials such as brick, stone, or wood.11 Having a successful and powerful empire was very important to the Roman’s as they believed that without a strong foundation, a strong empire would not be possible.12

The definition of high strength changes over the years as concrete strength used in the field increases. Any construction activity requires several materials such as concrete, steel, brick, stone, glass, clay, mud, wood, and so on. However, the cement concrete remains the main construction material used in construction industries. For its suitability and adaptability with respect to the changing environment, the concrete must be such that it can conserve resources, protect the environment, economize and lead to proper utilization of energy. To achieve this, major emphasis must be laid on the use of wastes and byproducts in cement and concrete used for new constructions. The utilization of recycled aggregate

Concrete is an artificial material in which the aggregates are bonded together by the cement when mixed with water. With the advancement of technology and increased field of application of concrete and mortars, the strength, workability, durability and other characteristics of the ordinary concrete can be made suitable for any situation. For this, definite proportions of cement, water, fine aggregate, coarse aggregate, mineral admixtures and chemical admixtures are

The evolution of concrete has allowed us to create more workable concrete and as a result allows better bonding due to the chemical reaction at a molecular level between the water and cement. This reaction bonds the aggregate and acts much like a “bridging” compound which binds the aggregate together.

The production of Portland cement is high-energy consumption and produce large amount emission of CO2. Previous research indicates that 0.98kg of CO2 will be created by production of 1kg of Portland cement, including 0.53g from decarbonisation, 0.33g from burning process plus 0.12g from generation of electricity power required. Therefore, for every ton of cement produced, an approximately equal amount of carbon dioxide is relapsed in to atmosphere [2阿三]. The world cement industry contributes 7% of total CO2 emission [3]. This leads to the research of seeking more environmental friendly cements. One of these alternative materials is alkali-activated slag (AAS) cement. Comparing with Ordinary Portland cement (OPC), the AAS has is own advantages. Firstly, it uses ground granulated blast-furnace slag (GGBS) as the binder material of concrete, which is a by-product from industry production. Secondly, AAS cement has low energy cost and low GHGs emissions. Finally, AAS concrete has excellent engineering

Reinforced concrete is one of the most important available materials for construction in Egypt and all over the world. It is used in almost all structures as: buildings, shells, bridges, tunnels, tanks and retaining walls. Concrete is made by mixing binding materials as sand and gravel held together with a paste of cement and water. The used of admixture is to change certain characteristic of concrete such as workability, durability and time of hardening. Some of concrete advantages are its high compressive strength, its ability to cast in almost any desired shape, its economical and fire resistance. Low tensile strength, low ductility and cracking consider one of its disadvantages. Regardless of this disadvantages, concrete still the materials of choice in construction.

The manufacturing process of cement consists of mixing, drying and grinding of limestone, clay and silica into composite mass. The

Abstract: Natural Sand which is used as a construction material is becoming scarce now-a-days and state governments are imposing restriction on unlimited excavation of Natural sand from river beds. This has made prices of Natural sand reach its peaks. Now there is every need for a suitable replacing material for Natural sand. An attempt is made in this context to replace natural sand by Granite fines by adopting M20 Grade concrete with a mix design of 1: 1.73: 3.1 of cement: Natural sand& Granite Powder : Gravel at a proportions of 0, 10%, 20%, 30% and 40% with a water cement ratio of 0.5. Acid Durability test was conducted on concrete cube specimen after 28 days water curing and 62 days soaking in Hydro Chloric Acid. After completion of this procedure Concrete cubes are tested for Compressive strength is tested and compared with Compressive strength of cubes which are not soaked in HCL after 90 Days. Cost analysis is done to ensure usage of Granite fines as replacement of Natural Sand does not vary the cost of project significantly.

For compressive strength test, cube specimens of dimensions 150 x 150 x 150 mm were cast for M60 grade of concrete. The moulds were filled with different proportions of cement,metakaolin and Fly Ash. Vibration was given to the moulds using the table vibrator. The top surface of specimen was leveled and finished. After 24 hours the specimens were demoulded and were being transferred to curing tank where in they were allowed to cure for 7,28and 56 days. After 7,28and 56 days curing, these cubes were tested on a digital compression testing machine as per I.S. 516-1959[14].

There has been increasing studies on magnesium silicate hydrate binder system as an eco-cement and its potential use for nuclear waste immobilization. The cementing properties and workability of cement paste and mortar using magnesium silicate hydrate binder were examined by compressive strength, flow test and scanning electron microscopy. The binder composition was proposed based on stoichiometric ratio. The results showed that magnesium silicate hydrate binder exhibits very high water demand due to containing high microfine content of amorphous silica (silica fume). However, it is possible to produce workable mixes at normal water to binder ratio (w/cm=0.40 and below) by use of polycarboxylate-based superplasticizer. Crushed quartz with smooth texture and particle size coarser than magnesium and silica fume was used as fillers to form ternary system. Use of crushed quartz fillers contributes to water reduction and improves packing density, hence increases strength of magnesium silicate hydrate binder system. Mortar samples of the binder containing 40% magnesium oxide, 40% silica fume (Mg/Si molar ratio = 1.50) and 20% crushed quartz fillers resulted in encouraging compressive strength of up to 70 MPa.

Nanoparticles (NPs) have recently received special attention because of their better performance when compared with traditional mineral additions. The addition of NPs can improve the properties of concrete due to the effect that the increased surface area has on reactivity and through filling the NPs of the cement paste. Some of these nano particles include Silicon dioxide, Copper oxide, Zinc peroxide, Titanium dioxide. The addition of silicon dioxide or titanium dioxide NPs improves the consistency of SCC mixes. Less bleeding and segregation are also observed in the SCC mixes containing these NPs. Also the addition of silicon dioxide or titanium dioxide NPs lead to a higher T50 time, which can be expected to improve the segregation resistance. Jalal et al. (2012, 2013). The incorporation of silicon dioxide NPs increases the V-funnel times of SCC mixes. Madandoust et al. (2011).

Rice husk ash (RHA), rich in silica content, can be produced from rice husk using appropriate combustion technique for use in concrete as a supplementary cementitious material. It is a fast growing pozzolan used in various cementitious activities which is highly encouraged due to vast abundance of rice in world. According to ( GRiSP 2013) over 90% of rice is produced in Asia.

Various researches have been done to explore the benefits of using crusher stone dust in concrete unit to enhancing the properties of concrete like compressive strength, flexural strength, etc replacing cement / fine aggregate by weight or by volume. In the previous investigation, researchers used fiber like polypropylene, nylon polyester, coconut coir, glass fiber, steel fiber etc. for the enhancement of mechanical properties and partial or full replacement of ingredient of concrete by fly ash, stone dust, and unconventional coarse aggregate in paver block. A brief description of previous research work on utilisation of alternative of fine aggregate and fiber used in concrete paver block is given below.