The reaction of alkaline solution (usually hydroxides or alkali metal silicates) with solid aluminosilicates can produce a group of cementitious binders called "geopolymer cement". The geopolymer binder structure is included fundamental of Si-o-Si and Si –o-Al tetrahedral bonds arranged in an aluminosilicate gel network where Al3+ sites charged – balanced by alkali cations.
Geopolymers have an extensive range of applications compared to usual construction materials due to their unique properties such as high resistance to salt and acid environments and high resistance to evaluated temperature and fire and their production greatly is reduced co2 emissions compared to Portland cement production.
The mechanism of geopolymer formation includes three stages:
1) Liberation (release) of silicate and aluminate species from of a solid source by dissolving of raw material in alkaline solution.
2) Hydrolyzation and depolymerization of solid particle.
3) Polycondensation of oligomers to form network gel structure.
The properties of geopolymer binders can depend on different synthesis parameters such as raw material, curing conditions and mix properties. The concentration of the alkaline activator plays an important role in the geopolymerization reaction and the densification of the microstructure. The literature has been reported that strength after one day curing increase from 40 to 90 MPa when alkaline activator containing of sodium silicate and NaOH was used instead of NaOH. Moreover, the use of sodium silicate accelerates the dissolution of the raw material.
The sodium aluminasilicate geopolymers can suffer from unpleasant efflorescence due to excess sodium oxide remaining unreacted in the material, particularly when they are syn...
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...in production of geopolymer cements. Many researchers have been reported to use of aluminasilicate industrial waste materials such as fly ash and metakaolin or artificial pozzolans.
In this work, the pumice – type pozzolan from Taftan mountain, Iran, used as source material which can activated with alkaline solution.
In this paper, firstly, the effect of efflorescence control admixture (Secar 71) on the strength mechanically has been investigated. Then, the development of ATR-FTIR analytical tools is used for the in situ analysis of reacting natural pozzolan based geopolymer gels. For this reason, data sets collected with a time travel of just 1 min at near – ambient reaction temperatures for up to one day. The collected small samples set have been obtained fundamental insight into the processes when efflorescance control admixture added to natural pozzolan.
The purpose for this lab was to use aluminum from a soda can to form a chemical compound known as hydrated potassium aluminum sulfate. In the lab aluminum waste were dissolved in KOH or potassium sulfide to form a complex alum. The solution was then filtered through gravity filtration to remove any solid material. 25 mLs of sulfuric acid was then added while gently boiling the solution resulting in crystals forming after cooling in an ice bath. The product was then collected and filter through vacuum filtration. Lastly, crystals were collected and weighed on a scale.
The purpose of the experiment was to determine the solubility of calcium sulfate. In Part A with the resin, The number of moles in the original CaSO4 sample was determined to be 3.69 x 10-4 moles, and the molarity of calcium in the saturated CaSO4 solution was determined to be 0.0148 M. The molarity of calcium in the saturated CaSO4 solution is equal to the solubility of CaSO4, so the solubility of CaSO4 was determined to be 0.0148 M at 18.9 °C. In Part B with the titration using EDTA, the moles of calcium in the original saturated calcium sulfate solution was determined to be 3.87 x 10-4 moles in Trial 1 and 3.74 x 10-4 moles in Trial 2, so the molarities of calcium in the saturated solution were determined to be 0.0155 M in Trial 1 and 0.0150
such as clay, shale, or blast-furnace slag. Either a dry or a wet process is
ferrate(VI) acts as an effective coagulant that is suitable for the removal of metals, non-metals,
When compressed or exposed to great heat the mineral binds together in small to large clumps forming calcium Carbonate Chips, however left in it's formed state it is powder, a chalk like substance. I could use either forms of the Calcium Carbonate for the experiment. Hydrochloric Acid, is a clear, colourless to slightly
Minerals are found worldwide and have many uses. The mineral gypsum is just one of the thousands named. Gypsum has always been a critical mineral in the building of many ancient constructions, and is being used still in today’s construction. (The History of Gypsum, 1985) It is speculated that the first use of it was in ancient Greece, where is was called “gypsos”, or “selenite”, but, gypsum’s first recorded use was in Ancient Egypt, where they used it in the building of the Pyramids. They used the material called “Alabaster” (which is a form of gypsum), but later in the 18th century, they realized that gypsum in its natural and raw state, was much too wet, so they altered it to create the building material called “Plaster of Paris”. (The Gypsum Association, n.d.)
The contraction moulding method can be used to process an acrylic denture base. In this method, bite blocks are fabricated in the lab and sent to the clinic for patient trial. These are then received from the clinic and teeth are mounted onto the bite blocks. The wax is eliminated and teeth are pressurized and attached onto a gypsum mould. (McCabe and Walls. 2008.) Sodium alginate is applied onto the mould to act as a separator to prevent any monomer from the acrylic base seeping into the base and the mould. Acrylic PMMA is applied onto the mould and either heat-cured or auto-polymerized. Both of these curing methods form the...
Ionomer: A polymer consisting of thermoplastic resins stabilized by ionic cross-linkages, used to make dental cement and sealants
Mount Pelée is composed mainly of hardened volcanic material. The volcanic rocks that Mount Pelée lies on are predominately composed of andesites with subordinates of dacites. This type of geochemistry is often very common throughout island arc calc-alkaline rocks. Based on the eruption style of Mount Pelée the volcanic material can be subdivided into different products. Roobol (1976) stated these four different groupings:
The Synthesis of Alum from Aluminum lab centralized on the creation of potassium aluminum sulfate dodecahydrate from a set amount of aluminum, and using quantitative analysis to then compare the actual yield to the theoretical yield. The synthesis of alum was conducted through a series of steps involving aluminum foil, potassium hydroxide, and sulfuric acid. Given that aluminum is amphoteric, meaning it can dissolve in both strong acids and strong bases, potassium hydroxide and sulfuric acid were both suitable for the dissolution of aluminum. There are multiple applications to synthesizing alum; from eliminating waste in the environment by repurposing, to utilizing alum as a medical treatment, the practicality of alum is immense.
Mixing sodium polyacrylate and water resulted in in a thick, clear gel that resembled ice or snow. It was sticky and wouldn’t form a shape if you held it in your hand and molded it. Adding heated water and sprinkling in poly(vinyl alcohol) to the surface of the water produced another sticky
Concrete and masonry products contain silica sand and rock containing silica. Since these products are primary materials for construction, construction workers may be easily exposed to respirable crystalline silica during activities such as the following:
Concrete is a composite material used widely in the construction industry. Concrete is basically a mixture of cement, water, aggregates and admixture (sometimes). Cement is a fine gray powder that consists of oxidizes calcium, silicon and aluminum. The aggregate used is normally gravel, crushed stone or sand. Admixture is a solid or liquid substance that gives a certain characteristics of the concrete. The cement reacts with water chemically and binds the aggregates together through a process called hydration during hardening or curing of concrete. It means that water helps in the hardening of the concrete while the cement bind the aggregate and also react with water to form a solid mass.
Minerals are found worldwide and have countless uses. The mineral gypsum, is just one of the thousands named. Gypsum has always been a critical mineral in the building of innumerable ancient constructions, and is still being used in today’s construction. (The History of Gypsum, 1985) It is speculated that the first use of it was in ancient Greece, where is was called “gypsos”, or “selenite”, but, gypsum’s first recorded usability was in Ancient Egypt, where it was used in the building of the Pyramids. They used the material called “Alabaster” (which is a form of gypsum), but later in the 18th century, they realized that gypsum in its natural and raw state, was much too wet, so they altered it to create the building material called “Plaster
Geotechnical Engineering covers the engineering properties of soils, the fundamentals of soil mechanics, and the application of geotechnical data and fundamentals to the design of foundation elements, earth-retaining structures, excavations, earth embankments and highway pavements.