Cement - Science topic

AFT (Accelerated Carbonation Test): This is a laboratory test used to assess the carbonation resistance of concrete. Carbonation is a chemical reaction where carbon dioxide from the air reacts with the calcium hydroxide in concrete to form calcium carbonate. AFT helps in predicting how well concrete will resist carbonation over time. AFt (Alumina Ferric Tri-sulfate): In the context of cement, AFt is one of the phases that can form in certain cementitious systems. It is a hydrate phase that includes aluminum, iron, and sulfate. AFt is often associated with the hydration of Portland cements containing significant amounts of sulfate.

The reaction takes place at the atomic or molecular level for the hydration reaction, and it works to accelerate the reaction, and this can be detected using a scanning electron microscope.

ِِDear Omidi

In my experience, when adding acid does not help, it is best to crush the sample with pliers (with the striate surface of the mouth) until the mud is removed from the sample. Then place the prepared sample in water for 48 hours, then grind the appropriate sieve sample under water for a few minutes. This method is helpful for separating the sediment on the isolated form in hard samples

Dear Abdullah Al Naser

Concrete workability, characterized by its slump, can fluctuate due to environmental variables such as temperature and humidity, as well as variations in constituent materials. Despite targeting a nominal water-cement ratio of 0.45, achieving the specified slump may necessitate adjustments. In response, a careful approach to adding water incrementally becomes imperative to restore slump while preserving the intended water-cement ratio. It is essential to exercise caution to avoid excessive water addition, which may compromise concrete strength and durability. Continuous monitoring and precise documentation of these adaptations are critical to ensuring the conformance and consistency of the concrete mixture, ultimately contributing to the successful execution of construction projects.

Dear Waldemar Łasica

Cement and asphalt function as binding materials but possess distinct properties and mechanisms, making their simultaneous use in a single concrete mix unconventional and impractical. Cement, a hydraulic binder, undergoes a chemical reaction with water to set and harden. In contrast, asphalt, a bituminous binder, requires heating to become pliable and cooling to solidify. These divergent processes result in materials incompatible in a mix, as the water necessary for cement hydration adversely affects asphalt’s integrity and bonding capability. Combining them would likely yield a mixture with compromised strength and durability, unsuitable for most construction applications. For optimal results, these binders are best utilized separately, each in applications that leverage their unique characteristics and benefits.

Ferro-cement toilets are a type of sanitary facility constructed using a technique of reinforced mortar. These toilets are relatively easy to build, durable, and are often used in situations where more conventional toilets aren't practical, such as in rural or underdeveloped areas. The operation mechanism of a ferro-cement toilet is quite simple and can be categorized into a few stages:

### Construction:

1. **Skeleton Making:** A skeleton structure is built using steel mesh or chicken wire and then shaped as desired. It can be formed into various shapes and sizes.

2. **Cement Work:** The skeleton is then covered with a thin layer of mortar (cement mixed with sand and water). This forms a durable structure once dried.

3. **Finishing:** Once the cement is cured, it is waterproofed and sometimes tiled for aesthetic and hygienic reasons.

### Operation Mechanism:

The operation mechanism of a ferro-cement toilet can be understood in several key stages:

1. **Use of the Toilet:** The toilet is used in a conventional manner.

2. **Waste Collection:** Depending on the design, waste may be directed to a pit, septic tank, or another kind of waste management system.

3. **Waste Treatment:** The waste undergoes natural decomposition, and if a septic system is used, solid waste is broken down in the septic tank.

4. **Waste Disposal/Use:** Liquid waste (effluent) is generally allowed to percolate into the ground. If the system is designed for it, solid waste might eventually be removed and used as compost.

### Maintenance:

- **Cleaning:** Regular cleaning is essential to maintain hygiene.

- **Checking:** Periodic checks for cracks and other damages to ensure that the ferro-cement is holding up.

- **Desludging:** In the case of pit toilets or septic tanks, periodic desludging may be necessary to remove solid waste when the system gets full.

### Advantages:

- **Durability:** Ferro-cement structures are robust and weather-resistant.

- **Cost-Effective:** They are relatively cheap to build and maintain.

- **Sustainability:** Can be implemented in regions with limited resources.

- **Adaptability:** Can be shaped and sized as per requirement.

### Challenges:

- **Manual Scavenging:** In some instances, manual desludging might be required which poses health and social risks.

- **Waste Management:** Safe and hygienic waste disposal/treatment must be assured.

- **Cultural Acceptability:** Sometimes, communities might be reluctant to use them due to socio-cultural beliefs.

Always note that the efficiency and health safety of any toilet system, including a ferro-cement toilet, largely depend on good maintenance practices and appropriate use. This ensures that the waste is managed effectively, and hygiene is maintained. Furthermore, waste should be handled, treated, and disposed of in a way that is safe for both people and the environment.

Hello

The effect of nanoclay on the strength will mainly depend on the percentage weight of nanoclay added and the type of cement material you are using as well as which type of strength you are measuring (compressive, tensile, flexural, impact, ...).

This is a very interesting review about the effect of nanoclays as fillers on different material properties.

السلام عليكم دكتورة امال العزيزة تكدرين اتروحين لقسم المعمار النهرين اكو دكتورة متخصصة بالبرنامج اجوبك على كل الاستفسارات تقبلي تحياتي@

MD simulations cannot be done for such a long time scale. If you implement several crude approximations you will not be able to get any useful data(provided you are able to perform it in the first place).

No, in EN 196 the water to binder ratio is fixed at 0.5, irrespective of the flow that you get. The proportions given in the original question are correct. You are allowed to use superplasticizers to compensate if you're using, for example, a cement with high water demand.

What is described above is the ASTM (C109/C109m) approach to standard mortar testing, where you aim for a uniform consistency in the flow table rather than a fixed water to cement (or binder) ratio. Which approach is better or worse is a completely different (and sort of endless) discussion that is still ongoing, but those are the two main trends.

Adding brick powder to cement can have a number of benefits, including:

The optimal addition percentage of brick powder depends on the type of concrete being used and the desired properties of the concrete. However, a typical addition percentage is 10-20%.

Here are some additional benefits of adding brick powder to cement:

Overall, adding brick powder to cement can have a number of benefits. It can help to reduce the cost, improve the strength, durability, workability, and fire resistance of concrete. The optimal addition percentage of brick powder depends on the type of concrete being used and the desired properties of the concrete. However, a typical addition percentage is 10-20%.

Good question.

I find that some of the most exciting topics I studied were often those into which I stumbled accidentally and not really by prudent planning, hence, I feel that it might be a wise strategy to follow two strands:

1) just follow your gut feeling and your nose and keep your eyes open on unexpected and strange and outlier type of phenomena where real scientific gold nuggets might be hidden, so to say, watch out off the beaten track.

2) looking for large scale societal needs on the other hand may indeed also be a pertinent strategy because I sometimes feel that our materials science community is a bit conservative and not really taking many risks in such areas nowadays, often rather following topics in which the (expected) impact is relatively high. My personal taste in this category are for instance research topics related to materials related questions such as (a) sustainability/ sustainable metallurgy / sustainable cement etc (i.e. real reduction of carbon dioxide emissions, beyond the usual bla bla); (b) materials for future water supply; (c) machine learning in material science and engineering ; (d) large (huge) scale energy storage for buffering abundant sustainable and grid electricity (i.e. Not just lithium based batteries for vehicles; but land based huge storage capacity): (e) electrochenistry and corrosion of materials (i.e. longevity) etc. etc.

I feel that - for getting good ideas in such directions - it is sometimes more helpful to read financial and business newspapers rather than our usual community material science journals, which, as I mentioned before, are sometimes chasing citation-measured impact alone but not real relevance for society and industry and not real curiosity-driven topics that sit between the established chairs. Open your eyes and look around you and think urself what your local, wider, or global society really needs from us materials scientists? Ideas will then come en gros.

Good luck.

One example what I chase at the moment :-)

Dear Rupesh Sah

To determine the precise dosage of admixture for concrete, a variety of factors must be taken into account. These factors include the unique project requirements, the properties of the admixture itself, and the characteristics of the cement being utilized. While the dosage range stated in the company's certificate can offer a general reference, it is crucial to seek advice from experts and conduct thorough testing in order to ascertain the most effective dosage for your particular application.

I would agree with the answers above. Setting time depends on a multitude of factors. Each project should determine how long a set time they need and then design the mix to set within the desired time span. The effect of admixtures is hard to predict. I had a case where we took a regular water reducing agent, dosed it at twice the manufacturer's recommended dose and achieved excellent retarding effects. In that case we delayed the set time for several hours (we had to transport concrete from a batch plant to a loading dock, transfer it by crane and bucket to barges fitted out with agitating hoppers, tow the barge to concrete placement site, and then place it with a crane barge and buckets in the piers), but we had rapid strength development after that.

So the practice to follow is to determine your requirements then design your mix.

One comment about superplasticizers: They typically increase the workability for about 30 minutes, then need to be re-dosed. You can add superplasticizers several times as the effect wanes.

I can think of many ways of using plastic waste to stabilize soil particles and improve cement-grade properties. Plastic wastes can include polythene, compound plastics, wrappers, and so on. One can stitch plastic pieces tightly with unconsolidated soil and apply various nominal stresses and shear forces. 1000-1500 Kpa can be tried at first with plastic-strips boundary at 5mm thickness and 1000 mm span. With notice taken to clay with 0.001 mm particle sizes, require the greatest compression to get rid of void pressures and hydrostatic pressures. Gravel has a large particle size of around 0.2-0.5 mm and requires less compaction. It can take a very long time to consolidate clay. One can increase plastic strips' density by wrapping soil particles with a thickness that can be increased for holding stresses. The holding stresses can be increased to 2000-3000 Kpa, with greater interbinds to hold silt or clay particles. The thickness of the plastic strips has to be increased to prevent rupturing and particle leaks. Solid plastic can be crushed and grid with asphalt, silt, and clay to make cement.

Depending on the percentage composition of the mix, compaction tests can prove the strength and yield of the different cement mixes.

Sedimentary rock forms when sediments are pressed and cemented together, or when minerals form from solutions. Magma forms when any type of rock is melted, a process driven by energy from Earth's interior. The plate motion that occurred near the Great Plains and Rocky Mountains uplifted igneous rock that formed underground.

mixing liquid sulfur into concrete mix would introduce incompatible materials and could negatively impact the performance of the concrete.

It is not a book, but also try:

Using recycled construction wastes in concrete or decarbonized cement could be an ideal intervention provided that the demand side could be adressed and/or realized. Producing cement using renewable energy sources could also compliment the first option with significant mitigation impact.

Thank you.

aysheshum.abebaw@aau.edu.et

Rajden Skhvitaridze, I meant binders not included in the standard.

In a thin section slide of a sandstone, cement and matrix are two important components that can be distinguished based on their mineral composition and texture.

To differentiate between cement and matrix in a thin section slide of a sandstone, you can use a polarizing microscope. Under polarized light, the cement and matrix will exhibit different colors and textures, allowing you to distinguish between them. The cement will appear brighter and more crystalline, while the matrix will appear duller and finer-grained.

Overall, understanding the difference between cement and matrix is important for interpreting the depositional environment and diagenetic history of a sandstone.

Thank you, Claude-Alain, I shall review these references with great interest.

Frank

You are correct that the production of Portland cement is responsible for significant CO2 emissions, with approximately 0.8–0.9 kg of CO2 emitted per kg of cement produced. The use of waste materials as partial replacements for cement, such as rice husk ash, fly ash, coconut shell ash, water hyacinth ash, bamboo leaf ash, and sugarcane bagasse ash, has been studied as a means to reduce these emissions. While the burning of these waste materials does produce CO2, the overall emissions tend to be lower than those associated with traditional cement production.

Quantifying the exact reduction in CO2 emissions from using these waste materials as cement replacements can be challenging due to several factors, including:

In many cases, the focus of research papers is on the mechanical properties and durability of concrete made with these alternative materials, rather than providing exact numbers for CO2 emissions reductions. However, it is generally accepted that utilizing waste materials as partial cement replacements can lead to a reduction in overall CO2 emissions, as these materials often have lower carbon footprints compared to traditional Portland cement production.

To obtain more specific numbers on CO2 emissions reductions, you may need to look for studies that have conducted life-cycle assessments (LCAs) for concrete made with these waste materials, as these assessments consider all aspects of production, including CO2 emissions.

I hope this helps!

What do you mean by "cement paste with the water content proportional to the amount of water in the mortar mixture"? Do you need to design the paste of the same consistency or strength? Because each needs other approach to the task.

Thank you, my teacher Thank you, my teacher

Acetone is a highly volatile compound and easily gets evaporated at normal temperature and in your case samples dipped in acetone were kept in an oven that had temperature, fluctuating between 75 and 80 degree Celsius . As per my opinion, acetone efficacy might had reduced because of which hydration might not had stopped. It is advisable to synthesize the samples again

Cement is an essential material for many construction projects, and its use has increased as population growth and urbanization increased. However, cement production is a significant source of carbon dioxide emissions and energy consumption, significantly contributing to climate change. As such, finding ways to replace cement with other materials partially is essential for sustainable and environmentally friendly construction. Research shows that the partial replacement of cement with other materials can improve the performance, durability, and environmental impact of construction materials and reduce the overall carbon footprint of the construction process. For example, fly ash, a byproduct of coal burning, can reduce the need for cement by up to 35%. In addition, other materials, such as slag, silica fume, and natural pozzolans, can be used to partially replace cement, with percentages ranging from 5% to 30%. When considering partial cement replacement, it is essential to evaluate why to start at 5% and what the 5% increment is. Starting at 5% is important because it allows researchers to gradually increase the replacement percentage while assessing the concrete's performance. Starting at a higher rate may lead to unexpected results, as the performance of the concrete may be better than initially anticipated. The 5% increment is essential as it allows researchers to gradually increase the percentage of replacement in small steps and assess the changes in performance. In conclusion, the partial replacement of cement with other materials is a critical way to reduce the environmental impact of construction. Research has shown that using different materials to replace cement partially can improve the performance, durability, and environmental impact of construction materials while reducing the overall carbon footprint of the construction process. When considering the partial replacement of cement, it is essential to evaluate why to start at 5% and what the 5% increment is to ensure the performance of the concrete is as expected. References: 1. Bhuian, S.N., and Abdalla, M. (2008). Cement replacement materials. Cement and Concrete Composites, 30(10): 667-673. 2. Sivakumar, M., and Murugan, R. (2013). Partial replacement of cement with fly ash. Indian Journal of Science and Technology, 6(10): 4491-4495. 3. Sharma, M., and Sharma, A. (2018). Partial replacement of cement with Silica Fume and Slag in concrete. International Journal of Engineering Research and Technology, 7(7): 1101-1105. 4. Hadi, M.S., and Ammar, M.A. (2010). Partial replacement of cement with natural pozzolan in concrete. International Journal of Engineering Research and Technology, 1(2): 13-18.

Thanks for your question, leachate testing for the solution concentration may be one of the options of for measurting the potential DEF-expansion. Please find the details in this manuscript.

To calculate the energy savings from replacing L-W absorbing cement flooring with epoxy light-wave reflecting cement flooring, you need to consider the following steps:

where:

It's important to note that the results of the calculation will depend on several factors such as the location of the building, the orientation of the flooring, and the climate. It's always a good idea to consult with a professional engineer or energy analyst to get a more accurate estimate.

Yes, you can use Ultrasonic Pulse Velocity test to determine the parameters of non-cement concrete materials such as rock or limestone. You can measure the parameters using ASTM standard: Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic Constants of Rock D 2845 – 00. This test method describes equipment and procedures for laboratory measurements of the pulse velocities of compression waves and shear waves in rock and the determination of ultrasonic elastic constants of an isotropic rock or one exhibiting slight anisotropy.

The internal stress of a natural rock may be less than or equal to and higher than loaded stress, this depends on the internal heterogeneity and defect distribution of the rock. The discrete element method can analyze the stress transfer of rock and soil.

Dear,

I suggest to use a wetting agent to engage better the aerogel inside the mixture. There are several types on market that work very well, but dosages can change depending on concentration of reactive content.

I think you could check about BASF portfolio.

These products can work at best if supported by polycarboxylates superplasticizer to manage the high amount of mixing water.

Best

Alex Reggiani

I cannot comment on this specific case, since this is not my domain of expertise, but I can add that some publishers do not care very much about the quality, novelty or whatever we may consider as quality indicator. For some of the open access journals (generalisation is not fair here as in many other situations), what matters is the payment of the processing fee.

I have the experience of reviewing for one publisher that claims to have papers published slightly above one week after reception, which is phantastic. The point is that reviews are mostly a make-believe action.

A few months ago, I was invited to make a review for one of those journals and was asked to do it in 10 days (after I having said that one week time was too short). After one week, the publisher had already two extremely superficial reviews that accepted the paper without major modifications, while discarding mine that added a 30 points list of arguments to reject it. The paper was published, and I never again accepted the many invitations they are continually making.

Therefore, we must read each new article with a critical sense and not accept that everything written can be taken as valid.

If the clinkerization reaction (the process of forming clinker, the main component of cement, from raw materials such as limestone and clay) occurs in a reducing environment, the quality of the cement may be affected. In a reducing environment, the iron in the raw materials may be reduced to metallic iron, which can cause the cement to be less durable and less resistant to sulfates. Additionally, the formation of metallic iron can lead to a decrease in the overall strength of the cement. Therefore, it is important to maintain an appropriate level of oxygen during the clinkerization reaction to ensure optimal cement quality.

'To make a shotcrete mix more environmentally friendly, replace part of the Portland cement with supplementary cementitious materials, such as fly ash or slag cement. Using recycled aggregates and reducing the water-cement ratio can also help shotcrete have less negative impact on the environment. For example, the use of fly ash instead of half the cement can significantly reduce CO2 emissions. It is possible to further reduce the overall environmental impact of shotcrete by taking into account its life cycle, including the amount of maintenance required. The environmental impact of shotcrete can be reduced by curing it with wet burlap or burlap cloth, which requires less energy.'

Silica Fume;

Water to cement ratio influences concrete permeability,

Etc.

Yes, helium pycnometry will work. If you want to stick with the volumetric method, you can substitute for the kerosene with an alcohol. See for example:

Comparative study of methods to measure the density of Cementious powders.

This paper can also be found on ResearchGate.

Good luck,

Dale

thank you sir Shashikant Kumar for you recommendations

The most recent versions of the CEMDATA database contain a subset dedicated to alkali-activated materials. If I'm not wrong, that database uses zeolites as proxies for N-A-S-H phases. Alternatively, you can create your own set of phases that are relevant in AAM. For reference, you can browse my publication:

Here, you'll be able to find a table with thermodynamic parameters for some relevant phases, comprising N-A-S-H (I used a two end-member solid solution), metakaolinite and alkali carbonates (thermonatrite, trona, pirssonite, gaylussite).

Once it enters your lungs there is a potential for numerous short and long-term problems. Particularly if it is un batched, the list is very long, research on this basis.

I would suspect that it would not be that different from OPC, whose value can easily be found in the literature. If you want an easy way to estimate its value, assuming you do not have thermoanalytical equipment (such as a Hot Disk) to make the measurement, you can easily construct a simple calorimeter using a beaker of solution of known heat capacity (an alcohol for instance, don't use water as it will react with the cement). Then, weigh the beaker empty, with the solution added (measure its temperature as well), and finally after adding the cement powder that it is first heated to an elevated (known) temperature (below the boiling point of the liquid of interest). Measuring the final temperature of the mixture in the beaker will allow a quick calculation via an energy balance (m1*deltaT1*Cp1=m2*deltaT2*Cp2) of the unknown heat capacity (neglecting any energy that is added if you stir the mixture, for example --- could further estimate this effect by performing experiment on a powder of known heat capacity...).

Geopolymers can be synthesized at low temperatures (25–80 °C) using an alkaline solution and an alumino-silicate material. Materials including amorphous silica, alumina, and alkali hydroxide (NaOH/KOH) are commonly used in the synthesis. For the synthesis of the binder, a variety of aluminosilicate materials can be employed. Metakaolin, rice husk ash, fly ash, and volcanic slag are among them.

From the perspective of cement, graphene oxide is just expensive soot. Soot has been added to cement in studies like this one:

A serious study would therefore compare:

a) no addition of soot

b) generic, chemically non-specific soot

c) fancy and expensive soot (aka graphene oxide)

By the way, In Poland we hardly ever use pure Portland cement in ordinary concrete - we often use the cements with fly ashes or blastfurnace slag.

An interesting topic!

Maybe...you can calculating manually the Relative Atomic Mass

Thank you very much for the answer. I have already seen overestimated Al2O3 wt. % in the quantitative analysis. But, I was struggling to get the amorphous content from the overestimated values. I will follow your recommended procedure. Thanking you again.

Hi, the liquid does not have to be changed for each test (fortunately because that would be complicated). The european standart EN 196-6 states "The manometer liquid shall be changed (or cleaned) after servicing or before a new calibration".

Note that you should calibrate the apparatus with reference materials (cement of known specific surface area). The apparatus constant shall be recalibrated with the reference material when another type of manometer fluid and/or a new manometer tube have been introduced.

Best wishes.

Maxime

Yes it has an annealing affect.it reduces the residual compressive stresses of cemented carbides.It will reduce the fracture toughness and flexural strength.Annealing in contrast will usually counter the strengthening effects of added reinforcements.Please do some review of annealing effects on cermets.

Depending on the annealing temperature and isothermal dwell time results can vary.

Buy a gas chromatograph for $250,000 and you'll know everything in no time

LOL....Mikhail

Often, a useful review paper can be produced efficiently if the following two conditions are met:

1) The paper does not already exist in the literature, and

2) you are starting a new research area and performing an extensive literature search so that you can get up to speed on the topic.

Defining of the scope of the review paper is still often a challenge, too broad and you won't be able to efficiently and effectively cover the topic(s) and too narrow and it will be of limited interest to the research community at large.

In addition to review papers, online bibliographies and annotated bibliographies for a research area can also be of interest and extreme value to others working in your field.

Happy review paper writing,

Dale

Effect of Different NaOH Solution Concentrations on ... - MDPI

https://www.mdpi.com › pdf

PDF

by Z Huang · 2021 · Cited by 1 — According to different ferronickel alloy production methods, ferronickel slag can be classified as electric furnace ferronickel slag (EEFS)

Brunauer–Emmett–Teller (BET) analysis is only specific surface area determination, that is why you got surface units (m2) over the specimen mass.

In my opinion, based on the quality of articles I have accessed in my area, I can say MDPI materials are of good quality.

low carbon cements

Yuri Mirgorod I get it. Thank you. Prof. Yuri Mirgorod

Lounis, yes it all depends on the type of the cement, amount of sulfur and other factors. Primary ettringite can stay in the paste without any harm, worst case scenario is when delayed ettringite formation is happening, then it is a trouble for concrete performance.

XRD determines crystallite size. SEM measures particle size. Each particle can consist of several crystallites, so usually particle is bigger (or much bigger) than crystallite. Your results are not surprising.

Mercury intrusion porosimetry (MIP) is a widely used technique for characterizing the distribution of pore sizes in cement-based materials.

Many work and literature related to this methods is available easily.

Jack,

If you are simply interested in permeability, Nicos Martys and I have developed a 3-D Stokes solver that works on a 3-D digital image. See:

Unfortunately, the ftp server that used to supply the codes has been taken offline, but if you provide me with your e-mail address (dalebentz49@gmail.com), I can send you a zip file with the codes, documentation, etc., if you are interested.

Best regards,

Dale

Dear Dhruva Dulani ,

A good LCA study will always have a clearly defined scope, phases and indicators and your study related with graphene composites are no exceptions. I would like to recommend you the following paper as a prototype:

paper‘s link

二氧化碳养护混凝土技术研究 (wanfangdata.com.cn)

二氧化碳养护混凝土技术研究 - 中国知网 (cnki.net)

Shuraik Kader Take a look

Dear, Calculating the environmental impact or circularity or carbon footprint is based on 1001 assumptions. What is the accurancy of these numbers??? fe impact is related to the energy source (nuclear power, renewables, ...)

It is impossible to express the complexity in one number. Environmental impact is also always a compromise with other needs of the product. The way we prefer is the evalation with the lifecycle based ecodesign rules of thumb gathered in checklists.

Good luck

You can get XRD equipment in AUST, Abuja and FEDERAL UNIVERSITY Lafiya.

Meanwhile, I do XRD data analysis including Rietveld refinement for inorganic materials generally. Contact: umaruahmadu@futminna.edu.ng

More information in this link

Thanks a lot.

1- The water to cement ratio is calculated by dividing the water in one cubic yard of the mix (in pounds) by the cement in the mix (in pounds). So if one cubic yard of the mix has 235 pounds of water and 470 pounds of cement– the mix is a. 50 water to cement ratio.The lower the water to cement ratio, the less air pores and the more compact the concrete structure, which translates into higher strength. The high amount of water will reduces the compressive strength of concrete because it will increases the gap between cement and aggregates thus air voids will increases.

2- The water obsorption is affected by the following factors Porosity of concrete, Relative Humidity, Surface area of element, Exposure period of wetting and drying.

The strength of cement dropped in the summer for the concrete and this issue demande to be carefully, because during the hot weather the water evaporates and make porous concrete and this result the decrease of the strength.

The Rice Husk Ash enhances the strength of cement-admixed clay by larger than 100% at 28 days.

Also check,

You would really need the isothermal calorimetry data at several temperatures to compute an activation energy. Then you can apply the basic principles of chemical engineering to numerically integrate over time the heat generation due to the reactions. You will need to specify the boundary conditions and geometry of your specimens. This can be done fairly straightforward in COMSOL or other 3-D computational packages. See the publications by Emilio Hernandez-Bautista that are available from his ResearchGate page and were part of his Ph.D. thesis

The class of cement is its compressive strength of 32.5 MPa; 42.5 MPa and 52.5 MPa. The cement class concerns its strength.

The type of cement is classified according to the components it is made of.

N and R are Early Strength Gain: Normal or High Gain. The process of strength growth as a function of time is different in the N and R cemeners.

yes

Hello, I think you can use blast furnace slag because it has a significant amorphous silica content due to cooling and quenching by water, while the amorphous silica content in steel slag is low and often crystalline. Moreover, blast furnace slags are hydraulic materials and you can determine their hydraulic activity of them according to standards.

there are many steps to ensure the quality for the plaster morter

Dear Tadele Yigrem Yes you can conduct a flexural strength test for plain concrete having pozzolanic materials as a partial replacement of cement. I think in this case, you should concern about the percentage of replacement. For different types of pozzolanic materials, the percentage of cement replacement is different. You can get the proper idea if go through some review papers. Here I attach you some experimental paper for your better understanding.

6-with-cover-page-v2.pdf (d1wqtxts1xzle7.cloudfront.net)

Performance of High Volume Fly Ash Concrete (ijirst.org)

Additionally, an important element is to check the compatibility of the chemical admixture with cement and the filler additive