Can I mix gypsum with cement?

Role of Gypsum in Cement – The main purpose of adding gypsum in the cement is to slow down the hydration process of cement once it is mixed with water. The process involved in hydration of cement is that, when the water is added into cement, it starts reacting with the C3A and hardens.

1. The time taken in this process is very less, which doesn’t allow time for transporting, mixing and placing.
2. When gypsum is added into the cement and water is added to it, reaction with C3A particles tales place to form ettringite.
3. This ettringite is initially formed as very fine-grained crystals, which form a coating on the surface of the C3A particles,These crystals are too small to bridge the gaps between the particles of cement.

The cement mix therefore remains plastic and workable. The time allowed for mixing, transporting and placing plays a important role in strength, composition and workabilty of concrete. As gypsum retards the process of hydration, it is termed as retarding agent of cement.

What happens when you add water to gypsum?

Gypsum: an old product with a new use Gypsum is calcium sulfate (CaSO 4 ). Refined gypsum in the anhydrite form (no water) is 29.4 percent calcium (Ca) and 23.5 percent sulfur (S). Usually, gypsum has water associated in the molecular structure (CaSO 4 ·2H2O) and is approximately 23.3 percent Ca and 18.5 percent S (plaster of paris).

1. Gypsum fertilizer usually has other impurities so grades are approximately 22 percent Ca and 17 percent S.
2. Gypsum is sparingly soluble (the reason wallboard gets soft but does not immediately dissolve when it gets wet, at least if only damp occasionally).
3. Gypsum is the neutral salt of a strong acid and strong base and does not increase or decrease acidity.

Dissolving gypsum in water or soil results in the following reaction: CaSO 4 ·2H 2 O = Ca 2 + + SO 4 2- + 2H 2 O. It adds calcium ions (Ca 2 +) and sulfate ions (SO 4 2-), but does not add or take away hydrogen ions (H+). Therefore, it does not act as a liming or acidifying material.

When should you put down gypsum?

Lawns – Established Lawns: Use 10 lbs. of gypsum per 150 square feet in the spring and in the fall. At these times of year, you can take advantage of seasonal moisture essential for the desired conditioning of the soil. New Lawns: Use 10 lbs. of gypsum per 100 square feet, incorporating into the soil. Water thoroughly before seeding.

How long does gypsum plaster last?

Gypsum as a processed mineral has evolved to become the most preferred building material as an alternative to other materials like cement, sand, wood, etc., It has unique properties and it is quite difficult to find another single material with all the properties of gypsum.

Gypsum plastering has revolutionized the Indian construction industry and has set new standards in quality and cost-optimality. Gypsum is a naturally occurring crystal of Calcium Sulphate (CaSO4.2H2O) formed during the geological period due to the evaporation of seawater. The thickness of gypsum deposits ranges from a few centimeters to several tens of meters.

This is then ground to a fine powder and then gently heated to about 150 degrees celsius. Some or all of the chemically formed water crystals evaporate to form a compound with fewer or no water molecules. This package is tightly packed and sealed for use as gypsum plaster.

1. While applying on the walls, this powdered compound is then mixed with water.
2. It hardens to form the gypsum plaster, which is in several ways better than the other kind of plaster-like sand cement plaster or lime plaster.
3. Fully hydrated gypsum may not get along with water while application as gypsum plaster, and so is the initial heating mandatory.

The shelf life of unapplied gypsum plaster is 3-4 months from the date of production. However, when this is stored in a setting with optimal humidity and temperature, gypsum plasters can last up to 6 months. Gypsum plaster is highly durable and produces a very smooth, crackless finish.

• The ability of gypsum to withstand fire, corrosion, and heat also increases the durability of the plaster and the buildings.
• Gypsum also has a low density and a higher compressive strength.
• When used in high-rise buildings, gypsum plasters reduce the dead weight of buildings.
• It increases their resistance to earthquakes and high-speed winds.

Though some people in the construction industry argue that gypsum plasters are a novice and are a modern construction material like Portland cement, it is an undeniable fact that it has been used along with lime in floors, walls, and ceilings across several countries ever since the 16th century.

What is the best way to apply gypsum?

Dealing with clay soils and conditioning them for planting By Heather Tait – Central Landscapes Planting Expert Mention that your garden has clay soil and you’ll experience either sympathetic groans for those who have the same, or smug smiles from gardeners with loamy or volcanic soil.

Clay is maligned for many reasons: its minuscule particles can form a hard, concrete-like consistency when dry, and a sticky mixture when wet. Clay holds more water than other soils, but often not in a way that allows plant roots to benefit from it. But it has properties that are beneficial once you control its less than desirable traits.

Clay soil contains minerals that are good for plants and, when other products are worked into it, can be an excellent growing media for many plants. Provided the clay has been loosened and ‘worked’ it holds moisture better than many soils, bringing earthworms up to the surface to aerate the compacted soil and aid plants to stay alive in harsh summers.

• Working clay ahead of planting Autumn is the best season because the soil is warm, moist with the rain and you can walk across the soil without it being muddy and in danger of compacting under your gumboots.
• Generally, areas that have not been planted will be a hotchpotch of weeds that colonise easily in clay.

They will have well established tough roots that are not easy to remove, because difficult growing conditions attract hardy plants. It is sometimes easier to spray off the area with glysophate (and a fixing agent to aid penetration) to get a broad coverage to kill off the weeds.

With areas that have been left for some time, a second spray will be beneficial. During this time you can apply gypsum to the surface area. Gypsum is a naturally occurring mineral, Calcium Sulphate, which loosens compacted soil, with no negative impacts on soil pH. (it is also the white product between the paper coating of Gib board).

Gypsum is most often available in powdered or granular form and can be spread over the area at the specified rate. After rain, the soil can be dug over with some compost and an optional second application of gypsum. Depending on how far into the dirt you can dig, either leave it to soften a bit longer (more rain required) or begin to dig holes for plants.

1. Tip: Potatoes are known for loosening hard soils.
2. If you are a keen vegetable gardener grow a crop of potatoes.
3. After harvest, the soil will be easier to work with, plus there are delicious potatoes to eat.
4. Planting into clay soils The general rule of thumb for planting it to dig the hole to the depth of the rootball (pot) and twice the width.

It is important that all the rootball goes in the hole as plants with exposed roots tend to stress and die. Place a handful of gypsum at the base of the hole and add a handful of compost or Garden Mix, before setting the rootball on top. Gypsum will continue to open up the clay for the roots and the growing media offers some extra nutrients. Some landscapers place special fertiliser tablets in planting holes at this time to add additional food, although it is not essential for most plants suited to growing in heavy soil. Before placing the rootball of the plant in the hole, it is important to check the plant roots. If there is a mass of roots and very little potting mix, b reaking up the root ball with hands or a knife prior to setting the plant into the hole helps to encourage root growth into the surrounding soil.

1. If you don’t do this, the roots may be so compacted from growing in a confined space that the roots will not extend outwards and grow.
2. Never place a dry plant in the hole – if necessary, soak it first in a bucket of water until the bubbles stop rising.
3. Placing soil and compost or Garden Mix around the plant is probably the most important part of the process.

Digging a hole in clay soil, even if you’ve worked the top area, still leaves the possibility that the hole could become a water reservoir in winter rain. When you replace soil around the plant to firm it in and complete the planting, this should be a blend (layers) of the soil that was originally there and some compost or Garden Mix.

The latter can work with the clay to help change the clay soil texture and add a bit of extra nutrient for the plant. Lastly, apply a layer of mulch even though we’re heading into winter. Why? Among its other characteristics, mulch has large particles which help move rainwater evenly around the soil area, plus it will head off competing weeds while the plant establishes.

Never place mulch right up against the stem of the plant though, form a ‘collar’ around it.

• Planting Product List
• Gypsum
• Fertiliser tablets (if desired)
• Compost or Garden Mix
• Mulch
• (All products are available from Central Landscapes)
• Ongoing annual care

Twice yearly applications in spring and summer of compost or Garden Mix, forked around plants are recommended. If left, clay tends to ‘revert’ to its original structure over a year. A layer of mulch every spring helps retain moisture during dry periods and that, in turn, keeps earthworms near the top of the soil, tunnelling through it and improving permeability.

1. Tough plants that are great in clay
2. Many New Zealand plants cope well in tough growing conditions.
3. These plants establish with ease, after the first year of care:
4. Trees – lemonwoods and pittosporums, kowhai, ngaio and ake ake
5. Shrubs – coprosma, camellias, corokias, manukas, some olearias, callistemon, westringea (Australian rosemary), viburnum
6. Grasses – Carex secta and carex virgata
7. Groundcovers – grevilleas, coprosmas, ivy
8. Root rot

Plants that suffer root rot (phytophthora) generally get it when planted in poorly drained clay soils. This can often be seen in rhododendrons and the NZ Griselinia. Reduce the risk by limiting the use of the plants to a few. Use Rootmate, which is a natural beneficial fungus in the hole at planting.

Can you build a house with gypsum?

Because gypsum is a fire-resistant substance, it is a suitable construction material.

Is gypsum harmful to humans?

Gypsum is a mineral calcium sulphate dihydrate with the chemical formula CaSO 4 ·2H 2 O a non-hazardous, non-toxic, inherently safe material. Gypsum-based plasters and plasterboards in the UK have no known adverse effect on health and are classified as non-hazardous.

The industry adheres to very strict quality controls for the manufacture or disposal of UK plasterboard. Gypsum as used by the members of GPDA has been registered in accordance with REACH (Registration, Evaluation, Authorisation & restriction of CHemicals). The overall conclusion in accordance with the REACH regulation is that there are no hazardous classifications associated with either mined or by-product gypsum.

Gypsum products are not classified as dangerous according to EU CLP Regulations. There are no long term adverse medical effects from ingestion of gypsum. If ingested, wash out the mouth and drink plenty of water. Plaster powders/dust potentially may irritate eyes or sensitive skin or irritate the respiratory system.

1. Any effects should be short term.
2. Rinse with water and wash from skin.
3. If in doubt contact a medical practitioner.
4. The UK and Irish manufacturers – British Gypsum, Gyproc, Knauf Drywall and Siniat – make their plasterboard products to strict specifications on gypsum purity.
5. Whether they use natural gypsum (calcium sulphate dihydrate) or FGD gypsum (a by-product from flue-gas cleaning at power stations), manufacturers inspect all material continually to ensure quality and performance of the product.

In use, plasterboard with FGD or natural gypsum is inert. Also, it does not change chemical composition, so can be recycled again and again. Suitable care and correct handling should be used when handling gypsum products. By voluntary agreement, gypsum plaster sacks are a maximum of 25kg.

Plasterboard handling should be assessed for risk before lifting and carrying. All standard plasterboard has safety information printed on the board. Mechanical aids are available and should be considered in the overall risk assessment. A guide to Manual Handling supported by GPDA and our member companies has been published and is available here.

The journey of plasterboard from factory to site involves many people, all of whom need to be able to work with a reduced risk of injury. The risk is predominantly due to the weight and unwieldy nature of the plasterboard. Any manual handling needs to be minimised by good planning and using equipment.

There needs to be good training and implementation of those practices. Most importantly, everyone needs to have the right attitude and behaviour so that no one in the industry is exposed to short or long-term risks that will affect their musculoskeletal health and ability to do their everyday activities, now or in the future.

GPDA members assisted with the Guide produced by FIS on Safe Ingress of Plasterboard available here, The majority of plasterboard construction waste is recycled, either into new plasterboard, in the production of cement or for agricultural use. The flow of plasterboard waste to landfill will continue to decrease with further emphasis on clean waste recycling, actively championed by all four manufacturers.

There has been good progress towards finding ways to recycle plasterboard demolition waste – at the present time it cannot return to the plasterboard manufacturing process, but it can be used for agricultural soil improvement. If gypsum waste must be landfilled, it is controlled by specific Environment Agency rules.

As a non-hazardous high-sulfate waste, there is a risk that large volumes of gypsum waste mixing with rainwater and organic waste materials could produce hydrogen sulphide, therefore it is not permitted in mixed waste but must be landfilled in dedicated, non-hazardous ‘high sulfate’ landfill cells, which minimise impact on the environment.

1. These cells are a potential exploitable source for recycled gypsum for the future.
2. In addition to its uses in building products and soil improvement, gypsum is also widely used in bread and dough mixes, as a stabiliser in other foodstuffs, as an aid to juice extraction in fruits and vegetables and to stimulate plant growth.

Gypsum has no known adverse effect on health. Gypsum is non-combustible and prevents flames from spreading.

Is gypsum stronger than drywall?

Drywall is made out of softer material called gypsum which doesn’t crack. Sheets of it are nailed into the wooden studs when finishing the interior of a house. Plaster, on the other hand, dries much harder than drywall, and is more labor-intensive and expensive.

Are gypsum walls strong?

From the fifth wall to gypsum-based partitions, home design trends that will rule 2018 Agencies A well-styled ceiling can make an impressive statement. By Sudeep Kolte From to walls, a handy guide for re-doing your home The fifth wall When we re-do our home, we often forget about the ceiling. A well-styled ceiling can make an impressive statement.

• One of the simplest yet most aesthetic forms of renovation, designer ceilings are a huge trend in decor.
• Gypsum-based ceilings are easy to experiment with by adding the shape and colour of your choice.
• Whether you use paint or wallpaper, gypsum-based designer ceilings last as long as a building and give a smooth, seamless finish.

From the bedroom to the living room, designer ceilings also provide a wide variety of lighting options while stashing away all that snaky-looking, electrical wiring. Wall art Photo frames on the wall are a trend of the past. Wall designs, paintings and decals is what you need to stay up to date.

However, if you feel your walls aren’t strong enough to sustain the weight of some paintings, there is absolutely no need to worry. A new range of plasterboards help you fix heavy and difficult items such as TVs, shelves, large paintings, etc. As part of a new range of gypsum-based plasterboards, these new walls are strong and durable, and do not require any of the special drills.

Cozy up Your living room is one of the most important spaces in your home. Whether you are entertaining guests or want to relax in a corner, walls with good thermal and acoustic insulation are always a plus. Partition walls create spaces for hosting guests, a play area for children, a TV room to relax over weekends or simply to add more space.

Gypsum-based partitions are extremely time-efficient and can be installed 3 to 4 times faster than masonry construction. panels are also relatively large compared to other materials and, therefore, they easily cover large wall and ceiling spaces. They require very few tools for construction, and can be fixed within few hours.

While their light weight makes them easy to carry, their durability allows a lifetime of strong, high quality walls. Highly versatile, gypsum boards can adapt to any form of decoration and also help reduce energy consumption caused by the air conditioning in your home.

• Gypsum walls, or drywall as they are called, also prevent unwanted sound from travelling to adjoining areas.
• So now go ahead, host that party at home without disturbing anyone.
• A splash of colour 2017 or 2018, colour never goes out of style.
• When unsure of what to choose between a wide range of vibrant and diverse shades, it is always best to go with the minimalist look.

One or two simple, low-tone shades and soft-washed pastels like dusty rose can work wonders for your home. Create space Nowadays, it’s all about creating space. If you have a couple of weeks to spare, re-doing your ceiling can make your room look more spacious.

Gypsum-based designer ceilings take about 1-2 weeks. However, if you are looking for quick and hassle-free design solutions, glass is the easiest answer. Adding glass-based windows or doors makes the room’s ceiling looks higher than usual and makes the room look larger than it is. If you want to go the extra mile, try placing tall mirrors and curtains of lighter material and softer shades which make the room look elongated.

– The author is VP Sales & Marketing, India Pvt Ltd – Gyproc Business. Disclaimer: The opinions expressed in this column are that of the writer. The facts and opinions expressed here do not reflect the views of www.economictimes.com. : From the fifth wall to gypsum-based partitions, home design trends that will rule 2018

Where do you apply gypsum?

How to use gypsum to improve your lawn – As a rule, gypsum is best cultivated and mixed into clay or heavy soils prior to laying turf or adding turf underlay. If you have an existing lawn that is suffering from compaction, using gypsum will also help relieve compaction in most clay or heavy soils.

Is gypsum a termite proof?

With more than 20 years of industry experience, I have come across different ceiling styles and understood the need for false ceilings. This is especially true for offices as they’re traditionally thought to be dull, uninspiring spaces. However, as I have come to learn, there’s much more to this ceiling option than meets the eye.

• It is from this experience that I would like to share the following tips to consider.
• The following 7 factors are key in selecting false ceilings that suit your office’s needs.1.
• Acoustic Performance : The first factor to have in mind is the acoustic performance that a false ceiling offers.
• Your space being an office, it’s important that there’s minimal sound either from impact on the roof or through transference.

This is why an acoustic tile ceiling is a great choice. This type is usually installed a few inches below the actual ceiling. The method creates an air pocket which acts as effective sound insulation. The same goes for other false ceilings. The difference however, is that acoustic tile ceilings are modified to provide extra sound insulation.2.

• Humidity and Moisture Resistance : The metal tile ceiling however, offers high humidity and moisture resistance.
• This is due to the nature of metals.
• They do not absorb moisture when correctly installed, therefore making them less susceptible to issues like mildew and mold.
• This makes for a very durable false ceiling that doesn’t need replacing as soon as other types may.3.

Fire Resistance : In addition, false ceilings come with the benefit of fire resistance. For example, gypsum board ceilings have a non-combustible core. Under high heat, they only release the moisture they contain as steam. This release is what retards the spread of fire.

They’re commonly used in constructions that need to meet strict fire regulations. Metal tile ceilings are also very handy in fire resistance. This is because they are highly fire resistant.4. Termite Resistance : Gypsum board, metal tile and acoustic tile ceilings are termite resistant. This is an important factor one should consider when choosing a false ceiling for an office.

Termites are known to wreak havoc when they attack structures, usually wooden ones. Their presence could lead to the collapse of an entire structure. Moreover, getting rid of them is an inconvenient and costly affair. The above types are well treated so termites never come knocking at your door.5.

Ease of Installation & Maintenance : Perhaps the best news for any constructor is that these types of false ceilings are quite easy to install. This rings especially true for the modular tile type ceilings. They come as ready tiles whose main labor is in piecing them together. Their nature also means that there’s minimal breaking risk involved in installing them.

The fact that they’re modular means that they will not crack or break easily.6. Electricity and Power Savings : The very installation of false ceilings comes with the benefit of saving on electric bills. For any company looking to run efficiently, this is a great relief.

The ceilings are installed about a foot lower than the original ceiling. This reduces the amount of airspace that an air conditioner is meant to service. In turn, this means a lower consumption of electricity by the conditioner thus lower maintenance costs of the office. The ceilings themselves also require very low maintenance.

This is due to the durable nature of the tiles or board. Once correctly installed, one may go for years without having to do anything to the ceiling. The key, therefore, is in proper installation. The gypsum board ceiling is especially sensitive in this matter.

1. Incorrect installation might lead to it absorbing water and creating a very unsightly ceiling.
2. However, if well done, the company may rest assured that they need not think about their ceiling anytime soon.7.
3. Aesthetics :In addition to these features, false ceilings allow one to customize their lighting as efficiently as possible.

This is in terms of energy saving. Acoustic tile ceilings, for example, are perfect for this. Acoustic tiles with reflective white surfaces can maximize the amount of light within an office. The natural light in a space is maximized through these reflective surfaces, reducing the need for artificial light and therefore the energy used.

They can also be combined with a secondary source of light. This provides the rays of light that will be bounced off the ceiling surface. At the same time, it reduces the amount of energy used by about 20%. This significantly cuts down on the office’s energy costs as well as contributing to going green.

COST BENEFITS The biggest question is definitely that of cost versus benefit provided by false ceilings. It is a question whose answer can be put quite simply, they’re worth every penny spent on them. The gypsum board ceiling, for example, is less cost intensive than the metal or acoustic tile ceilings.

They, however, take much longer than the latter two to install. They’re also more susceptible to damage if improperly installed. However, based on all the tips listed above, whichever false ceiling one chooses to use, they are more than safe. The office will definitely gain in the long term from having the false ceilings put in.

If you’re not entirely convinced about it, the following is one little advantage to false ceilings that nobody can pass up. False ceilings are not only functional, but aesthetic. This is an important factor to consider because the ceiling of any space either provides a feeling of space and unity, or absolutely ruins the rest of the space.

Their method of installation allows for creation of patterns, which in turn create a visually interesting ceiling. For any company, this can be a statement of uniqueness. They also allow one to hide imperfections like wires, pipes and beams on the roof. One can also customize them to match the aesthetic theme of the rest of the space.

Simply, there are no limitations to what one can create with false ceilings! Want to know more ? Get in touch for a FREE consulting call with our Experts !

What are the 3 types of gypsum materials?

Discussion – Surface microhardness and compressive strength are crucial parameters in fabrication of dental cast and dies to resist laboratory manipulative forces during indirect dental restoration construction. Moreover, the setting expansion (dimensional changes during setting) is a critical factor for the successful fabrication of accurate sized wax pattern and consequently dental restoration (Abdelaziz et al.2002 ).

1. Several attempts have been performed to enhance the mechanical properties of dental plaster that include incorporation of various additives such as Arabic gum, silicone oxide, glass fibers, and calcium oxide (Razak et al.2017 ; Akkus et al.2018 ).
2. In the current study, aluminum oxide nanoparticles have been used as fillers to reinforce the conventional dental plaster.

The conventional dental plaster was used as negative control, while the improved stone was served as a positive control. The set gypsum material final surface microhardness strength and setting expansion are prominently controlled by the crystal particle number and entanglement, and any substance that inhibits the crystal growth or decrease their number will affect their strength and abrasion resistance (Jayaprakash et al.2014 ).

The gypsum product materials utilized for construction of final casts or dies should express a high resistance to scratching and sufficient strength that withstand the manipulated force during laboratory manipulation and wax pattern construction, which in turn changed to final indirect dental restorations.

After calcium sulfate hemihydrate (gypsum products) mixing with water, they began to set and undergo dimensional changes. This expansion mostly is due to growth in both number and size of the growing calcium sulfate dihydrate crystals. Entanglements of the growing crystals push against each other lead to a phenomena called “crystal outward thrusting action.” Expansion will occur as a result of occupying the crystals a larger space volume.

• Additionally, internal porosity in the set mass will be created due to the outward thrust action (Michalakis et al.2012 ).
• Minimization of the setting expansion of the gypsum products upon transformation of calcium sulfate hemihydrate to dihydrate to very little values is mandatory to get a proper fitting of the indirect dental restoration to tooth surface (Razak et al.2017 ).

Aluminum oxide nanoparticles are considered as a chemically inert ceramic, non-toxic, and white in color. It could serve as promising fillers into advanced dental materials. They have a great capability to produce act as reinforcing agent to increase surface microhardness and enhance the mechanical properties (Alhareb et al.2017 ).

The null hypothesis was that there has no significant difference between the surface microhardness, compressive strength, and setting expansion between conventional and reinforced dental plaster with 10 wt.% aluminum oxide nanoparticles fillers. The higher surface microhardness of the novel reinforced dental plaster with 10 wt.% aluminum oxide nanoparticle fillers may be due to the effect of incorporation of hard aluminum oxide ceramic nanoparticle fillers into gypsum products (Alhareb et al.2017 ; Razak et al.2017 ).

The increase in compressive strength of the reinforced dental plaster group may be due to two facts: the addition of strong aluminum oxide ceramic nanoparticle fillers into gypsum products, in addition to the reduction in calcium sulfate powder on expense of the added aluminum oxide nanoparticle filler that will lead to decrease in the formed calcium sulfate dihydrate crystals, subsequently decrease the formation of internal porosity in the set materials (Alhareb et al.2017 ; Razak et al.2017 ).

The little dimensional changes of the reinforced dental plaster group may be attributed to the lowest setting expansion values due to the addition of aluminum oxide nanoparticle fillers on expense of calcium sulfate dihydrate powder. Thus, reduction in the produced amount is the calcium sulfate dihydrate crystals with subsequent decrease in the resultant outward thrust action of the formed crystals, hence reduction in the linear expansion (Razak et al.2017 ).

Moreover, the aluminum oxide in nanoparticle sizes has a very fine size and high surface area which may cause great interfacial interaction with matrix tha enables them to restrict the molecular motion of calcium sulfate dihydrate, thus decrease their expansion during setting (Safi 2014 ).

The requirement of the American Dental Association Specification No.25 and ISO standard 6873:1998 for gypsum products that used for construction of final casts and dies included that the compressive strength values should be not less than 35 MPa. Moreover, the setting expansion should be not more than the range of 0.0–0.15 % (ADA 1985 )(ISO 1998 ).

The null hypothesis was rejected as the innovative dental plaster reinforced by 10 wt.% aluminum oxide nanoparticle fillers achieved improvement in both surface microhardness and compressive strength with very little setting expansion. Our novel reinforced dental plaster gets a compressive strength values higher than those obtained from other studies that depends on the addition of glass fibers, gum Arabic, ferric oxide, and calcium oxide (Razak et al.2017 )(A Hatim et al.2007 ).

Furthermore, it gives a low setting expansion than study that depends on epoxy resin nanoparticle and carbone nanostructure fillers (Kreve 2018 ). Moreover, it gets a higher compressive strength and surface microhardness and lower setting expansion values than those of our previous investigation of microsized aluminum oxide fillers (Hamdy, 2019 ).

Our study gives a higher compressive strength and low setting expansion than that of improved stone which not studied before.

What are the 3 gypsum products?

Discussion – Surface microhardness and compressive strength are crucial parameters in fabrication of dental cast and dies to resist laboratory manipulative forces during indirect dental restoration construction. Moreover, the setting expansion (dimensional changes during setting) is a critical factor for the successful fabrication of accurate sized wax pattern and consequently dental restoration (Abdelaziz et al.2002 ).

1. Several attempts have been performed to enhance the mechanical properties of dental plaster that include incorporation of various additives such as Arabic gum, silicone oxide, glass fibers, and calcium oxide (Razak et al.2017 ; Akkus et al.2018 ).
2. In the current study, aluminum oxide nanoparticles have been used as fillers to reinforce the conventional dental plaster.

The conventional dental plaster was used as negative control, while the improved stone was served as a positive control. The set gypsum material final surface microhardness strength and setting expansion are prominently controlled by the crystal particle number and entanglement, and any substance that inhibits the crystal growth or decrease their number will affect their strength and abrasion resistance (Jayaprakash et al.2014 ).

The gypsum product materials utilized for construction of final casts or dies should express a high resistance to scratching and sufficient strength that withstand the manipulated force during laboratory manipulation and wax pattern construction, which in turn changed to final indirect dental restorations.

After calcium sulfate hemihydrate (gypsum products) mixing with water, they began to set and undergo dimensional changes. This expansion mostly is due to growth in both number and size of the growing calcium sulfate dihydrate crystals. Entanglements of the growing crystals push against each other lead to a phenomena called “crystal outward thrusting action.” Expansion will occur as a result of occupying the crystals a larger space volume.

Additionally, internal porosity in the set mass will be created due to the outward thrust action (Michalakis et al.2012 ). Minimization of the setting expansion of the gypsum products upon transformation of calcium sulfate hemihydrate to dihydrate to very little values is mandatory to get a proper fitting of the indirect dental restoration to tooth surface (Razak et al.2017 ).

Aluminum oxide nanoparticles are considered as a chemically inert ceramic, non-toxic, and white in color. It could serve as promising fillers into advanced dental materials. They have a great capability to produce act as reinforcing agent to increase surface microhardness and enhance the mechanical properties (Alhareb et al.2017 ).

1. The null hypothesis was that there has no significant difference between the surface microhardness, compressive strength, and setting expansion between conventional and reinforced dental plaster with 10 wt.% aluminum oxide nanoparticles fillers.
2. The higher surface microhardness of the novel reinforced dental plaster with 10 wt.% aluminum oxide nanoparticle fillers may be due to the effect of incorporation of hard aluminum oxide ceramic nanoparticle fillers into gypsum products (Alhareb et al.2017 ; Razak et al.2017 ).

The increase in compressive strength of the reinforced dental plaster group may be due to two facts: the addition of strong aluminum oxide ceramic nanoparticle fillers into gypsum products, in addition to the reduction in calcium sulfate powder on expense of the added aluminum oxide nanoparticle filler that will lead to decrease in the formed calcium sulfate dihydrate crystals, subsequently decrease the formation of internal porosity in the set materials (Alhareb et al.2017 ; Razak et al.2017 ).

The little dimensional changes of the reinforced dental plaster group may be attributed to the lowest setting expansion values due to the addition of aluminum oxide nanoparticle fillers on expense of calcium sulfate dihydrate powder. Thus, reduction in the produced amount is the calcium sulfate dihydrate crystals with subsequent decrease in the resultant outward thrust action of the formed crystals, hence reduction in the linear expansion (Razak et al.2017 ).

Moreover, the aluminum oxide in nanoparticle sizes has a very fine size and high surface area which may cause great interfacial interaction with matrix tha enables them to restrict the molecular motion of calcium sulfate dihydrate, thus decrease their expansion during setting (Safi 2014 ).

The requirement of the American Dental Association Specification No.25 and ISO standard 6873:1998 for gypsum products that used for construction of final casts and dies included that the compressive strength values should be not less than 35 MPa. Moreover, the setting expansion should be not more than the range of 0.0–0.15 % (ADA 1985 )(ISO 1998 ).

The null hypothesis was rejected as the innovative dental plaster reinforced by 10 wt.% aluminum oxide nanoparticle fillers achieved improvement in both surface microhardness and compressive strength with very little setting expansion. Our novel reinforced dental plaster gets a compressive strength values higher than those obtained from other studies that depends on the addition of glass fibers, gum Arabic, ferric oxide, and calcium oxide (Razak et al.2017 )(A Hatim et al.2007 ).

1. Furthermore, it gives a low setting expansion than study that depends on epoxy resin nanoparticle and carbone nanostructure fillers (Kreve 2018 ).
2. Moreover, it gets a higher compressive strength and surface microhardness and lower setting expansion values than those of our previous investigation of microsized aluminum oxide fillers (Hamdy, 2019 ).

Our study gives a higher compressive strength and low setting expansion than that of improved stone which not studied before.

How is gypsum used in soil?

You do not have to work gypsum into the soil – simply use a spreader to distribute it over the surface of your lawn or garden. For garden application, also mix in compost or organic matter. Water immediately after application.

What plants is gypsum good for?

Gypsum Provides Essential Sulfur – Plants require sulfur for protein synthesis. Sulfur is also an important component to nodule formation on legume roots and is responsible for the characteristic smell of onions and garlic. Though this deficiency is becoming more common than in past, it is still not more common than calcium deficiency, sulfur deficiency occurs throughout North America, especially in areas where rainfall totals are high.

Where is gypsum most commonly found?

Relation to Mining – IMAR 7 th Edition Most of the world’s gypsum is produced by surface-mining operations. In the United States, gypsum is mined in about 19 states. The states producing the most gypsum are Oklahoma, Iowa, Nevada, Texas, and California.

Together, these states account for about two-thirds of the United States’ annual production of gypsum. Over 30 million tons of gypsum is consumed in the United States annually. Canada, Mexico and Spain are other significant producers of raw gypsum. In all, more than 90 countries produce gypsum. In most open pit gypsum operations, benches are drilled and blasted using ammonium nitrate as the explosive.

Because gypsum is so soft, most drills can drill through it at a rate of roughly 23 ft per minute. Sometimes the drill holes become wet, which can cause problems with the ammonium nitrate. In these cases the ammonium nitrate is bagged in plastic bags before being lowered into the blast hole.

Nehru Baral