Questions related to Cement
How do diverse aggressive media and modifiers interact with magnesia cements under varying conditions, and what advanced methods enable precise engineering for optimal performance in practical applications.
Thank you for guiding me. I am preparing samples of isolated planktic Foraminifera from limestone, when some crushed stone samples are placed in acid, instead of being soft and ready to be washed, they become hard and cemented. What is the cause of this issue?
We all know that the water cement ration 0.45, which may vary due to the Mix-Design. But during the concrete due to changes of weather & materials SSD condition the slump changed (Generally Dropped) in mid time.
So looking the help from experience person, how many water may use for 1mm/5mm slump gaining. The equations also okay, I can check with our mix-design for getting the value.
Thanks in advance for your assistance.
I want to run long term temperature cycles e.g. 30 years day and night temp variation cycles, in molecular dynamics. How can I do it? If someone can refer research articles in this regard, it would be really helpful
is the following mixture respect the europeans standards?
cement => 1 part
sand => 3 parts
water => 1/2 part
For a mix design of Grade 30 or Grade 40 concrete, whether the admixtures (retarder and superplasticizer) will chemically react with the OPC or BHC in a different manner and results changes in initial and final setting time of concrete?
I am looking for research papers, articles, and relevant information on the utilization of plastic waste in stabilizing loose soils and how plastic waste affects the engineering properties of cement.
Any help will be greatly appreciated.
What kind of rock is formed when fragments are pressed and cemented together and how did you form magma where on the landscape did the magma form?
Mitigating the effects of climate change through reducing the amount of cement used or using recycled construction wastes in concrete or decarbonized cement. WE can discuss and explore more in this area.
The IPCC has only recently acknowledged that cement and concrete in the built environment constitute a significant carbon sink due to the process of carbonation. Much has been written about the factor determining carbonation, but no universally accepted indices would guide decision-making to build lower carbon structures.
As we know, 1kg of cement production produces about 0.8–0.9 kg of CO2 and other greenhouse gases. Many studies have been done on the partial replacement of cement with ash from different waste materials, i.e., rice husk ash, fly ash, coconut shell ash, water hyacinth, bamboo leaf ash, sugarcane bagasse ash, and many more. The burning of these materials will also produce CO2. Everyone is mentioning in their paper that it reduced CO2 emissions, but I did not find it in numbers.
Let's say that I have a given mortar mixture with the w/c ratio at 0.74. Consumptions are as follows: Cement - 339.8 kg/m3; Sand - 1676.7 kg/m3; Water - 251.8 kg/m3. The sand is siliceous, with a water absorption of 0.1%. Imagine I am preparing 1m3 of the mixture.
Is it possible to design a cement paste with the water content proportional to the amount of water in the mortar mixture (only excluding the water parcel related to the sand)?
From my perspective, I would discount 2.52 g for the absorption. But I would also need to discount the amount of water needed to wet the grains. Maybe a layer of water times the specific surface area? Any ideas or literature recommendations?
I really appreciate your insights. Thanks!
28 days cured alkali activated binder samples were immersed in acetone to stop the hydration reaction before characterization. The samples immersed in acetone were stored in oven in a controlled temperature of 22 +/- 2 degree Celsius. That oven has a temperature range of up to 80 degree Celsius.
While my samples were stored , the oven malfunctioned and the temperature raised to its maximum limit (80 degree Celsius). When I went to store few more sample, I saw the temperature was fluctuating between 75 and 80 degree Celsius and the acetone in vails was boiling (as it has low boiling point).
With the acetone wash, the hydration reaction of samples was stopped but I am wondering if the samples stored in that acetone are still suitable for characterization? or I should synthesize the samples again. Kindly comment your opinion.
i am working on research regarding partial replacement of cement. i have seen some research with related topics and most of them used 5%, 10%, 15% and so on. i planning to use those percentage too but i want to know why start at 5% and what's with the 5% increment?
I am starting to work on a project concerning DEF or SEF as a damage mechanism. We are not able to find any standard accelerated tests for DEF. I have read about Duggan, Fu, and Kelham methods etc. They seem to be quite old. Are there any standard accelerated tests that have been developed for this?
Hi all, does anybody know how to calculate the energy savings from replacing light-wave absorbing cement flooring with epoxy light-wave reflecting cement flooring?
Can Ultrasonic pulse velocity test be used to determine parameters for non cement concrete material such as limestone ( used to build in heritage structures) ? if it is possible, how to measure parameters ? What are the guidelines?
I am studying stress transfer during hydraulic fracturing. However, the stress transfer mechanism is out of my research field. For a simple example, when a cement sample is loaded by compressive stress, if the stress value at a point inside the cement sample is lower than the loaded one (?), how do we get to know the detailed stress inside the cement?
When trying to make concrete containing aerogel, the hydrophobic nature of the aerogel made the actual manufacturing process very difficult (the aerogel floats on the top side of the cement slurry because of its density, and it takes a long time to mix with the cement slurry), so I wanted to ask if there was a dispersion agent that could facilitate the manufacturing process of the samples.
Recently, i have been subjected to many rejection for the reason of novelty which does not making sense at most. I came through the following abstract in the aforementioned journal and although my manuscript is discussing very importnat applicable topic in porous concrete i came through recent published and accepted article with the below abstract.
Calcium sulfoaluminate (CSA) cement can be used as a replacement for Portland cement to reduce CO2 emissions. However, the performance of CSA cement remains unknown with regard to its hydration mechanism, mechanical and long-term performance. Therefore, it would be beneficial to consolidate the literature on CSA cement to facilitate its use in the construction industry. To this end, recent progress and technical challenges of using CSA cement are discussed in this paper. We begin with the introduction of the different types of CSA cement and the manufacturing process. This is followed by a detailed discussion on the hydration mechanisms and phase assemblage, mechanical performance, and long-term durability of CSA cement. Finally, the applications of CSA cement are discussed.
My question does the journal accept or reject papers on the basis of relationship and politics is the research include also some corroupted and bais basis.
Please i would like to be answered for once
I am really curious to know why we make clinker in oxidizing conditions? of course because of burning the fuel for the kiln but do the environment really affects the clinker quality.
What will happen to the cement quality if the Clinkerization reaction happen in reducing environment?
As it is evident, concrete production industry, especially cement has put the environment in a crucial situation via greenhouse gas production, as well as natural resources (e.g., sand) consumption. what could be done in order to make a shotcrete mix design more sustainable in order to achieve a good properties (e.g., mechanical, workability, etc.) product with less environmental footprints?
On November 28, 2003, the government of India has banned the free import of kerosene. As a result, kerosene became extremely scarce. As per IS 4031 Part-11 1988, section-5, "Kerosine free of water, or naphtha having a specific gravity not less than 0.7313 shall be used in the density determination". So, what alternatives to kerosene can be used to determine the specific gravity of cement?
Looking forward for the answers from the researchers who are working on cementitious materials.
Hello dear researchers!
I found in my results that the increase in the specific surface area of C-S-H (obtained by BET N2 methode) led to an increase in the hydration degree. Any suggestions or articles about this?
I want to know what are the chemicals that help to activate geopolymer in order to quickly take and harden in a short time close to the hardening of cement
In order to strengthen the cement matrix with combined graphene oxide and metakaolin, in order to their interactions as with cement, I want to inquire if anyone here has a suitable mixing method,
- Concrete is the heart of civil engineers, as it plays a crucial role in binding materials properly. Nowadays construction costs are very high due to the scarcity or unavailability of natural resources. This problem can be resolved by the replacement of concrete with a different material that is not conventional in terms of required properties. From previous scientists' research, cement, sand, and metal are replaced by using different artiﬁcial materials.
- I wonder what other new materials can as binding to reduce cement or concrete?
Since Hydration Reaction is well established, now Carbonation of non- hydraulic cement is Hot Topic because of its low lime content and CO2 sequestration ability. while onsite construction is not suitable for carbonation a well-established pre-fabrication industry can utilize this technique. there is significantly less structured data available and standard practice is not available.
join me in this discussion panel and way ahead to sustainable future of construction industry
I am trying to understand the correlation between free ions content (Ca, K, P...) and degradation of cementitious surfaces. Is there a method or calculation to estimate its content?
For Cement Powders: I want to use XRD internal method (Spiking with a crystalline material) to calculate the amorphous content in my system. I have added 20% of Al2O3 (99.9% crystallinity) to the cement powder. I want to know, how can I calculate the amorphous content using High score Plus software?
This is for the determination of fineness in cement, we are using the air permeability (Blaine) method. I was wondering whther we can ise the same manometer liquid for different test samples?
or we need to change the liquid every time we teat a new sample?
How can we know the flue gas composition from Coal-fired power plants, Refineries, Cement and Steel Industry?
Please share your knowledge and experience. How to write a review paper related to cement-based materials/concrete technology? What characteristics review paper should have? What should be the purpose of writing a review paper?
Hybrid concrete consisting of fly ash (FA), ordinary portland cement (OPC), slag (GGBS) and sodium hydroxide (NaOH) shows deprived results for compressive strength. While alkali activated material cosisting of FA, GGBS and NaOH offers better compressive strength.
Why the partial (20-40%) replacement of aluminosilicate materials (FA and GGBS) with OPC reduces the strength concretes?
Previous researches based on FA, OPC and NaOH offers higher strength.
what is the relationship between the surface area and the hydration degree of cement? Does the increase in the surface area cause the hydration degree of calcium silicate hydrate C-S-H gel to rise?
I have data for a BET analysis (surface area) in order to gain information about the surface area and the pore size of my samples (cement, cement with additive). and when I got the results, I get nothing about this size pores, just the surface area (m2/g) of the two samples and the volume of applied pressure, is there a method to extract the pore size of my sample from the information I have acquired (The test is to apply nitrogen pressure to the sample)?
Currently, the acceptance rate of MDPI Materials is about 65%. Normally, this rate is 20-30% for other journals. Is MDPI Materials publishing so many papers for money and compromising on the quality of work?
I'm looking for some help about the understanding of adsorption kinetics of composite cement paste (cement+quartz) towards starch.
My experiment like this: the starch dosage is calculated according to the powder mass cement+quartz), and the water-powder ratio is 0.4. For a given starch dosage, that is, the same starch concentration (g/L). In different systems (OPC_pure cement, Qz15_85% cement+15% quartz, Qz30_70% cement+30% quartz) calculated in the adsorption amount (normalization to cement mass) is different (mg/g cement). But the adsorption amount (normalized to powder mass) is consistent.
So I don't know how to interpret them. Or my analysis is wrong.
- PS: The literature result shows that quartz basically does not adsorb starch.
I have SEM images of cement paste samples, references and others doped with graphene oxide. After 28 days of hydration, the ettringite still appeared in all samples, since it is known that after 12 days of hydration, it turns and disappears.
what are the reasons for this appearance at a later age?
I have some x-ray tomography images of cements and I am interested in modelling their permeability using Lattice Boltzmann Modelling.
Does anyone know of any code to simulate flow throughout such a medium?
I need to complete a life cycle assessment of mixing graphene and cement to create a composite. I have found the OpenLCA software and tried to use the free databases available.
The elcd database has portland cement available, however no other free database has any values of graphene. Would anyone know a free database that contains graphene values and process, or anyway I could get these values to create my own data?
Recently, I have an idea: an innovation in the manufacture of traditional concrete. My idea is to use tailings instead of part of cement and add fly ash, steel slag and other materials as aggregate to reduce the proportion of cement to 0.3. And the use of foaming technology, plus some additives to increase the porosity of concrete. The concrete made in this way is cured in the environment of high temperature and high concentration of CO2, the mechanical strength is improved by CO2 and alkaline metal carbonation, and the CO2 is fixed.
To this end, I did a simple experiment. Here are some data: I made 4*4*4cm3 concrete according to the picture below,：
put them in 100% CO2 boxes, and did a comparative experiment on air curing, but nothing else. After a certain period of time, the removal results are as follows. I want to know in what ways I should improve my experiment. I have looked up a lot of articles, and the only clue at present is to carry out steam pre-curing before maintenance to ensure its water content.
You are welcome to post the discussion. If you need any other information, please let me know in the comments.
Cement has been in human use throughout history, and due to its binding nature, it is regarded as the backbone of the construction industry. A recent edition of the journal Nano Energy published the results from major breakthrough research conducted by engineers from Incheon National University, Kyung Hee University, and Korea University. The researchers have invented a cement-based composite (CBC) that can be used in concrete to develop electrical properties without affecting its structural performance. But what if cement could be used to generate electricity?
Any ideas from researchers?
I need to know how to modify an agg process, based in an u-so process in GaBi. For example, I modified some flows of the cement BR (u-so) in ecoinvent 3.6 creating a copy, but I need to modify this date in agg process for I can calculate the environmental impacts, how can I vincule the modifications from u-so process with the agg process?
We have many standards and method for determination of water absorption of the cement paste, mortar and concrete. Is there the standard for determination of water absorption the powder such as fly ash?
What is the difference between the amount of moisture content (%) and water absorption (%) of powders such as fly ash or pozzolan materials?
In ASTM C618 &Table 1: Moisture content, max for fly ash class N, F and C is 3%.
Though, we can use ASTM C311-13, procedure No.11 and No.12 for calculation of Moisture content.
Is there any the standard for determination of water absorption of the powder such as fly ash or pozzolan materials?
The subject of my research is jet grout spoil and I want to do various tests on it.
Thank you for answering my questions.
Cement strength dropped at summer period, this problem repeated annually. Any one face this problem before and what is his recommendation?
There are a number of scholars studied the blending of agro-waste ashes with cement and mentioned some of reasons to blend them
Is it possible to convert the Heat power obtained from the calorimeter for a given cement paste into an adiabatic temperature rise curve?
Can anyone guide me in this regard?
I am aware that EN Standards have defined the following types of cement:
CEM I 42.5 N
CEM I 42.5 R
CEM I 52.5 N
CEM I 52.5 R
where N refers to Ordinary Early Strength and R refers to High Early Strength. In addition 42.5 and 52.5 refers to minimum 28-Day Strength.
But my question is how do we produce CEM I 42.5 R and CEM I 52.5 N?
Because in literature it is reported that increasing fineness increase early strength but how do we increase 28-Day strength then?
We are researchers conducting a market research study on sustainable cement/concrete. This information will serve as input into research on the development of cement/concrete. Your responses are voluntary and will be held in strict confidence. All responses will be compiled and analyzed at an aggregate level. Neither you nor your responses will be identified. If you have any questions, please contact email@example.com. Thank you for your willingness to participate in this survey! Your candid responses are greatly appreciated. This survey should take less than 5 minutes to complete. https://lnkd.in/dUizjzc
Hello all, We are researchers conducting a market research study on sustainable cement/concrete. This information will serve as input into research on the development of cement/concrete. Your responses are voluntary and will be held in strict confidence. All responses will be compiled and analyzed at an aggregate level. Neither you nor your responses will be identified. If you have any questions, please contact firstname.lastname@example.org. Thank you for your willingness to participate in this survey! Your candid responses are greatly appreciated. This survey should take less than 5 minutes to complete. https://lnkd.in/dUizjzc
I am looking to use the pozzolanic properties of slag, but it is impossible due to its crystalline structure. Therefore, the slag structure must be transformed to amorphous. What is your solution for converting slag crystal structure to amorphous?
Thanks for your contribution.
what kind of tests should perform on self consolidated cement paste incorporating suplementary cementious materials such as fly ash, rice husk, etc. i am using differnt kind of materials for the measuring the durablity of the self consolidated cement paste after using other differnt materials. so what kind of test should i perform on such material