Concrete - Science topic

Hello, Professor. Is it useful to place a thick steel plate -well anchored by bolts in a column at the face of an external concrete beam-column joint- and expect this configuration to behave as an interior joint?

Born from the imagination of Planck, Schrödinger, Bohr, and others, is incomplete, unsound, and doomed to disappear sooner or later.

Concrete artificial intelligence predicts that quantum physics does not exist, but rather a description of the quadratic attraction of classical physics.

I’m curious to hear about the maximum compressive strength of concrete that you have achieved in laboratory conditions. What values have you recorded?

I need to know if we use plastic in concrete will provide positive impact on structure

I modeled a concrete beam using Abaqus (Dynamic Explicit, CDP model, 10mm mesh) and compared the numerical and experimental load-displacement curves. While the peak load matches well, the initial stiffness and post-peak behavior show significant differences. What could be the possible reasons for this discrepancy?

I have been simulating low velocity impact test on concrete brick using concrete damage plasticity model. The impactor is penetrating the concrete brick instead of forming crack on the brick upon impact. What migt be the issue here? I am using dunamic/explicit solver. Below I have attached the picture of simulation. Please help me figure this out as i am new to learning Abaqus. Thank you

Recently I've been working on a simulation of concrete 3D printing, and has successfully simulated a layer-by-layer 3D printing process using model change. However, when I proceeded to try simulations of uneven load during the 3D printing process(which is dividing a layer into like 4 parts and activating them one by one in a clockwise order, then move on to the next layer.), there was an error message even before Step-1 finished, saying that the global mass matrix is singular. So I did as it hinted and set *dynamic, singular mass=warning, so I could finish Step-1, where all element sets except the 1st set are deactivated until their activation step.

However, Step-2(where the 2nd element set gets reactivated) went straight from U1 to U5, there were zero pivot points located between the 2 adjacent element sets, and elements distorting excessively for unknown reasons.

The most blizzard part is that when I consulted one of the senior students who had already successfully finished his similar model, and he sent me his FUNCTIONAL model(.inp), there were still the same error messages that I encountered when I tried to run his model. Could it be that we ran the same model on different versions of Abaqus that led to different outcomes? Mine was Abaqus 2021 and his was 2023.

Here are some of my error messages and zero pivot points.

The entire model was functional until the same layer was set to be activated in 4 adjacent steps.

Quels sont vos critères prioritaires pour évaluer et sélectionner des ressources (livres, articles, bases de données, etc.) afin d’assurer la pertinence et la qualité des informations utilisées dans vos recherches ?

Pouvez-vous partager des exemples concrets ou des outils spécifiques que vous trouvez particulièrement efficaces ?

Merci

whether any future scope remedies are needed in the areas of sustainability, concrete, materials, etc.

Dear Research Community,

I am modelling the stress-strain behaviour of FRP-confined concrete in ABAQUS. I have written a USDFLD sub-routine. My ABAQUS stress-strain curve follows the expected curve up to the peak stress. After that, the stress is overshot by about 5 MPa (which is about 8% higher than expected). The gradient of my ABAQUS curve is the same as the expected curve - just 5 MPa stress higher than expected in the post-peak region. What could be the problem, and how do I rectify it?

Any suggestions are welcome. Thank you.

Holly

All the elements/mesh are distorting presenting unrealistic fracture. How can i solve?What might be the issue. Please help me

Hello, My name is Nathan Ruas Alves, I am a civil engineer graduated from the Federal University of Uberlândia and I am currently studying for a master's degree in Civil Engineering with an emphasis on Structures. I would like to ask for your kind collaboration in solving a problem I am facing in my research. I have tried several approaches, but so far, I have not been successful. I am studying smooth concrete slabs reinforced with non-metallic GFRP rebars. The slabs are being simulated by a quarter of the entire slab to facilitate processing. I am using a mesh size of 35 mm, viscosity of 0.0001 and dilatancy angle of 43º. The interaction of the concrete slab with the GFRP rebars is of Embedded region and the Actuator (element considered as rigid in numerical modeling) with the top of the slab where the load is applied was of Constraint type Tie type. For the constitutive model of the concrete I am using the fib Model Code 2010 model for compression and for tension I am using Hordijk (1991). It is worth mentioning that I am using symmetry boundary conditions on the faces of the slabs! The concrete compression and tension damage model that I am using is from the formulation proposed by Yu et al. (2010) which represents a simplified method, as it consists only of subtracting from the unit the ratio between the acting stress and the maximum resistant stress. What I don't understand is why in all the simulations I perform mixing dilatancy or viscosity angles or meshes the stress x displacement curve always looks like this before the peak. How can I reduce this peak to get closer to the experimental one?

A six-story building with a height of 18 m and a floor area of 100 m² contains 35 m³ of concrete per floor and 50 m³ in the foundation.

Total Weight Calculation:

Total concrete volume:

35×6+50=260 m3

Total weight (with a density of 2500 kg/m³):

260×2500=650,000 kg=650 tons

Inertia Due to Earthquake Acceleration (1.5g):

Inertial force:

1.5×650=975 tons

Overturning Moment Calculation:

The center of gravity is located at:

18m/2=9m

Assuming a uniform distribution, the overturning moment is:

9×975=8775 ton⋅m

Since the floor plan area is 10 × 10 meters, the lever arm at the base (i.e., the distance from the overturning axis to the center of the counteracting weight) is:

10/2=5m

Counteracting Moment Calculation:

The total weight that can act as a counteracting force is:

(650×1.5)×5=975×5=4875 ton⋅m

Comparison with Overturning Moment:

The previously calculated overturning moment is:

9×975=8775 ton⋅m

Since 8775 > 4875, the building cannot resist overturning based solely on its own weight.

Conclusion:

Overturning is possible if no additional stabilization methods are implemented, such as foundation piles, ground anchoring, retaining walls, or other seismic techniques.

However, in practice, buildings do not overturn!

Instead, they collapse due to joint and beam failures, as beams and joints do not have the necessary strength to transfer such forces. As a result, the structure fails before reaching the point of full overturning.

If the joints and beams had the necessary strength to transfer the overturning forces, the structure would undergo overturning rather than collapse. However, since this is not the case, it is essential to explore alternative design approaches to protect the joints and beams.

Anchoring the four corners of the structure to the ground would enhance its stability but would not eliminate the moments in the joints and beams. The optimal solution is to eliminate both the overturning moment and the bending moment in the columns and walls by anchoring them to the foundation ground.

The elongated wall is the most suitable structural element for this purpose, as it offers high stiffness, enhanced dynamic response, and a long lever arm, which generates strong counteracting moments. These moments become particularly effective when the wall’s ends are anchored to the ground.

Hello, everyone!

I'm currently exploring innovative solutions in the field of concrete materials, specifically focusing on "Concrete shrinkage and the integration of self-sensing properties," which is a major part of my PhD thesis. If anyone is working on similar research or has the expertise in this area, feel free to reach out to me for collaboration. Thank you for your time, Have a nice Day

The compressive force in the wall section, combined with the anchoring of tendons in the ground, halts the bending moment by increasing stiffness, eliminates tension and cracking, improves the shear angles caused by diagonal tension, enhances the section's resistance to base shear, mitigates the wall's overturning moment and joint moments, increases the load-bearing capacity of the ground and the structure, and prevents the shear failure of concrete cover.

Science has proven all of this; these are established facts—facts about prestressing and anchoring.

All these measures halt deformation, and without deformation, failure does not occur. They increase the dynamic capacity of the wall without increasing mass, which, incidentally, also increases seismic loads and costs.

The question is: why aren’t these measures applied in construction to address earthquakes?

Dear Research Community,

I am modelling FRP-confined concrete, and I have written a USDFLD sub-routine to define the field variable, which is lateral confining pressure. The stress-strain curve of FRP-confined concrete should go up after the peak stress, due to the lateral confinement provided by the FRP jacket. However, my stress-strain curve matches that of unconfined concrete up until the peak stress (which is expected), after which it dips like unconfined concrete, before increasing again. The stress-strain curve should not dip. What are the possible causes, and how can I rectify them?

Concrete formulation

Dear N cycling community,

I have been looking for studies reporting the difference in the gross N mineralization rates in soils under oxic vs. anoxic conditions?

Lower rate is expected under anoxia I assume, but would anyone have any concrete numbers to this, or good hints about references? Also studies reporting mean residence time for ammonium under oxic vs. anoxic conditions would be helpful.

Best, Maija

As part of my project, I aim to develop the lightest possible concrete while reducing the associated carbon footprint. I plan to completely replace Portland cement with blast furnace slag (GGBFS) and use lime as a chemical activator. I would like to hear your opinions on the feasibility of such an approach, as well as any information on its potential impact on density and environmental benefits (e.g., CO₂ emission reduction). Do you have examples of successful applications or recommendations on optimal dosages and potential challenges to anticipate? Thank you for your contributions!

concrete is essential in construction but also it's heavy in weight that effect in construction

i need to know another materials which can replace concrete or method to reduce weight of concrete

"I am looking for recent studies or data that illustrate the economic impact of food fraud, including estimates of direct and indirect costs, losses in the supply chain, and effects on consumer trust. Additionally, I am interested in concrete examples of food fraud cases and their financial impact on companies. Any references or literature sources would be very helpful.

I want to absorb my readings as much as possible, while still having some free time! I switched recently to a digital note taking platform called notion, but I want to make sure I didn't unintentionally sacrifice power for speed. I've heard things about digital vs paper notes, but nothing super concrete.

I am using a circular disc type PZT. Since I couldn't find a definitive source, I would like to confirm whether I should place the metal side, which is brass, directly on the surface, or should the ceramic side face the surface instead?

I am modelling a UHPFRC jacketed column in abaqus. After reaching ultimate load sudden decrease in load is observed...ACC to experiment it should be gradual decrease.

Hello... Is there a concept that stipulates that the increases obtained in the flexural or tensile test results must be higher than the increases obtained in the compressive strength assuming the use of steel fibers in a fixed ratio for geopolymer concrete with the reference mixture and adding a specific nanomaterial to it, or could it be less?

What are the realistic applications of self-compacting geopolymer concrete in the world? Are there names of projects implemented with this concrete around the world? Please mention the names and materials that were used for this concrete.

Question: I am looking for data about crops ( 🌽 🥔 🍠 🍅 🌶 🍋 🍆 🥑 🍌 🥕 🥒 - whatever), soil nutrients and soil parameters (like silt and clay amount, pH value, soil moisture, nitrogen, phosphate, etc.) and the resulting yield. Country or year does not matter. Any concrete ideas? Maybe someone has something unpublished and would like to share? Thanks a million!

I have modeled a prestressed concrete beam in ABAQUS using following element type:

Concrete- C3D8R, Steel Strand- T3D2.

I have considered elastic and plastic behavior of both steel and concrete(CDP). While comparing load-deflection curve from both experiment and FEA, it has given me pretty much accurate value for ultimate load. However, the elastic response of the structure is much more stiffer from experiment data. I have already updated the FE model based on constructed specimen such as diameter of steel bar and prestress strand, concrete strength. What could be the problem?

I want to do cyclic loading on a concrete column by using simplest method not want accurate results. Suggest some easiest model except CDP or any simplest way to analysis a concrete column under cyclic loading

I need help with suggestions for a thesis title as a requirement for me to achieve a bachelor's degree in engineering

When calculating the punching shear resistance of foundations according to the equations of the various codes, the participation of the plain concrete footing is neglected regardless of its thickness. Is the plain concrete footing ineffective in resisting punching shear even if its thickness is greater than or equal to 30 cm, or are there other reasons for neglecting its effect?

During the preparation of alkali activated concrete there involves a step to decide which activator must be used to activate the precursor. In order to know the the efficiency of the activator we need to know the basic reaction taking place during activation between the activator and the precursor.

In human psychology, time is a conscious experience—a construct reflecting the sequence of existence and events. In cosmology and physical sciences, time is often defined as the indefinite, continuous progression of existence and events in a uniform and irreversible succession, extending from the past, through the present, and into the future. This progression is conceptualized as a fourth dimension that exists above the three spatial dimensions.

Time is fundamentally a measurement to quantify changes in material reality. The SI unit of time, the second, is defined by measuring the electronic transition frequency of caesium atoms. Time is also recognized as one of the seven fundamental physical quantities in both the International System of Units (SI) and the International System of Quantities.

In physics, time is commonly defined by its measurement—essentially, "what a clock reads."

This description suggests that time, in its conventional understanding across various scientific disciplines and human experience, is an abstract concept, not a real, tangible entity. While time provides a framework for understanding the succession of events, it does not have a direct physical existence as space does in three dimensions. Time is often viewed as a hyper-dimensional abstraction—imperceptible and unreachable beyond the three-dimensional spatial realm.

However, relativity challenges this interpretation by treating time as a real entity—integrated with space to form a four-dimensional space-time continuum where time becomes subject to physical modifications, such as time dilation. This relativistic concept implies that time is not only concrete but also malleable under the influence of velocity and gravity, leading to discrepancies with other scientific interpretations that consider time an abstract or imaginary concept.

One of the main contentions is that time dilation, a cornerstone of relativity, effectively violates the standardization of time by presenting it as something dilatable, thereby questioning the uniformity and constancy of time itself. The traditional time scale based on a 360-degree cycle—representing a consistent progression—is disrupted by the relativistic notion of time dilation, which converts abstract time into something perceived as "real" or "natural." This treatment of time also seems to ignore the conscious human experience, which understands time as a subjective, psychological construct.

Furthermore, if time is not directly reachable—being an abstract hyper-dimensional concept—what then is the "time" that a clock measures? Clocks are designed to provide a standardized approximation of cosmic time through calibrated frequency counts, such as the electronic transitions of caesium atoms. However, the physical manifestation of time in clocks is inherently subject to distortions, primarily due to gravitational effects. Gravity affects mass and energy, altering the oscillation rates of clocks and resulting in time distortions. Consequently, even the most accurate atomic clocks require periodic adjustments to compensate for these external influences.

The discrepancy between the "real time" measured by clocks and the "conceptual time" of cosmic progression raises further questions about the nature of time. Clocks, intended to represent a uniform progression of time, must contend with gravitational influences that disrupt this uniformity, necessitating ongoing corrections. This challenges the idea that time is a tangible, concrete entity and supports the view that it remains fundamentally an abstract concept—a conceptual framework through which we interpret the order of existence and events.

In short, while relativistic physics proposes that time is a real entity susceptible to physical modifications like time dilation, this interpretation remains contentious when viewed through the lens of broader scientific understanding. Time appears more consistent with an abstract or imaginary concept, a near-approximate representation that is susceptible to external influences, yet ultimately remains beyond the realm of tangible existence.

Hi Everyone

It's been a while that I've been trying to model a Concrete beam for bending test but the more I study about Concrete damage plasticity, the more I get confused.

I have read articles and watched videos but still can't calculate CDP parameters. Can anyone help me how to obtain compression and tension behaviour and its damage parameters?

Thanks

Best Regards.

I am currently working with recycled aggregate concrete and using finite element simulations to predict its behavior under different conditions. I have faced several challenges in accurately modeling the properties of this material, especially considering its heterogeneous nature and the variability of recycled aggregates.

I would like to know what specific challenges others have encountered while modeling recycled aggregate concrete in finite element analysis and what methods or techniques have proven effective in addressing these issues. Any insights into improving the accuracy and reliability of these models would be greatly appreciated.

1. Data Quality and Availability.

2. Feature Engineering.

3.Model Selection and Complexity.

4. Generalization to New Data.

5. Computational Resources.

6. Integration with Existing Systems.

7. Regulatory and Safety Concerns.

We all know what pre-stretching and packing does

I'm just showing you what they do when combined with the ground.

1. I stopped the bending moment of walls and columns.

We all know that prestressing makes stiff sections.

2. I stopped the overturning moment - bending of the walls

We all know that bracing does not allow for rotation the horizontal and vertical displacement.

3. I stopped the tension on the sides of the walls

We all know that compression eliminates tension and an equilibrium of forces occurs because two equal and opposite forces such as compression and tension cancel each other out.

4. I stopped the base cutting

The friction coming from the wall compression increases the shear strength of the cross-section to the shear stress. In a simulation I performed, I applied compression at 50% of the strength of the cross-section with a concrete safety factor of 1.5 and the result showed that the strength of the cross-section to base shear increased by 30.9%

5. I stopped shearing

We all know that compression improves the oblique tensile trajectories causing shear and this is because friction increases.

6. I stopped the inelastic deformation of the load-bearing structure.

When you stop wall bending moment and wall overturning moment using additionally the external force of the soil then you control the displacement hence the inelastic failure.

7. I stopped the torques at the nodes

After stopping bending moment and overturning moment I stopped the two causes that creates the moments at the nodes.

8. I stopped the shear failure in the concrete overlay occurring around the concrete steel interface due to the super tensile strength of the steel.

Without synergy there is no shear failure and since the tendon has free passage through passage tubes it will never fail by shear since it does not undergo shear.

9. I increased the strength of the concrete without increasing the mass and quality of the concrete which increases inertia and cost.

Prestressing increases the active cross section of the concrete Even the overlay concrete is active, hence its compressive strength. This is not the case in reinforced concrete because it cracks easily and only a small part of its cross-section receives the compression.

10. I increased the bearing capacity of the foundation soil to the moment in compression and tension.

Since the prestressing caused by the soil surface opens the mechanism which compacts the foundation soil in all directions and on the other hand by filling the borehole with reinforced concrete, it creates an expanding pile which transfers the static loads both to the slopes of the borehole and to the deeper areas of the soil where we have more compacted strong soils suitable to receive static and seismic loads.

11. I increased the earthquake bearing capacity of structures to such a degree that it is impossible to have even a small inelastic failure in the largest recorded earthquake on planet earth.

I did experiments with 5 times the acceleration of the largest recorded earthquake and nothing happened to the scaled specimen.

12. I checked the increase in displacement means of the construction ground resonance and duration.

When you control with the ground force the inelastic deformation in each seismic loading cycle then any elastic displacement remains unchanged.

Dear researchers,

Selecting a function of the right form (linear, polynomial, exponential, power law ...) to fit a set of data usually requires the use of some knowledge and some trial-and-error experimentation.

In practice, I guess researchers:

- first select a function form and

- then use a chosen method (e.g., ordinary least squares OLS) to estimate the parameters of that model minimising a defined objective (e. g: minimising the RMSE)

The web contains numerous guidelines on how to estimate the parameters for a given objective . However, at first, from my understanding, the function form must be assumed.

My concern comes from a very concrete issue.

I have numerous inputs and one output. I would like to build a model to predict the output. I've checked numerous laws in the form:

ex:

test 1: F1=aX^2+b*X+c*Y^2+d^Y+e*(X*Y)**2+f*(X*Y)

test 2: F2=a*ln(X)+Y^b+c

..

For each test, I've used train/test subsets, OLS method to find parameters and then RMSE computation, ... very usual process I guess.

Is there research work/tools to automatically generate the functions to evaluate?

I've been searching online for days so any help will be very much appreciated.

Regards,

1.Use the small weak cross-sections of beam and wall elements to take the moments at the nodes, instead of using the strong large cross-sections. This goes against science. I use the large strong cross sections.

2. You only use the element cross sections to obtain the earthquake stresses. This goes against science. I use in addition the external ground force to derive earthquake intensities.

3.To increase the strength of the sections you add more reinforcement and concrete increasing the mass which increases the seismic loads without increasing the strength because no matter how many irons you put in the butter the concrete will break once they start pulling.

I am using artificial compression to increase the concrete's active cross section, dynamic, stiffness, and bearing capacity to the lateral earthquake loads and base shear and all shear in general without increasing the mass and by sending the stresses into the ground I am removing them from the cross sections.

4. Concrete in two things does not resist a. tension b. shear. You are forcing it to take tension and shear. Concrete can only withstand compression. But even in compression it can resist compression you have disabled it because as you design only a small part of the cross section receives compression.

I design so that the whole cross-section is active in compression since that is what the prestressing does, secondly I design so that there is no shear failure in the concrete overlay, and I apply compression to counteract the tension which compression is resisted by the concrete.

The new seismic technology aims to solve all existing problems of structures that occur at high seismic ground accelerations.

The method applies controlled artificial compression with a stress ranging at 50% of the strength of the cross-section with a concrete safety factor of 1.5, at the ends of all longitudinal walls of reinforced concrete, applied between the nodes of the top level and the base. It also braces the lower ends of the tension tendons to the foundation soil using expandable anchorage mechanisms, which are activated from the foundation soil level, prior to the construction erection works, using hydraulic tensioners, which apply pulling intensities to excite the mechanisms and open them, which are twice the axial calculation loads.

Can we make the earth's faults resistant and prevent it from breaking? And have safe and secure homes?

There are several ways to prevent ground faults from shaking. According to most geologists, what causes the rupture of the earth's fault and the strong shaking of the fault and the release of energy from the center of the earthquake from the fault and the L waves or the P, S and L waves from inside the earth, is excessive pressure on the fault in millions of years. And most importantly, the penetration of water, humidity and cold into the faults is more in the cold seasons of the year; It happens like autumn, winter and spring and also in the early morning and night. And it causes the energy inside them to be released, and check this in the time series of several years of earthquakes, we understand the reason for the cold and water penetration into the faults, especially at night and early morning when the weather gets colder. This rupture of faults is more in the early morning and most earthquakes occur in the early morning from 4 am to 6 am or from 9 pm to 2 am. Underground and fault is easier. And now geologists have realized that man himself can create earthquakes in 3 or 4 ways, i.e. artificial earthquakes. For example, in the faults and in the parts where there is displacement in the folded layers of the earth, by digging Amin wells and injecting water pressure into these wells, it penetrates the layers inside the fault and causes energy to be released from within. They fall to the ground. The energy and rupture of the fault generated from the center of the artificial earthquake was created so that it would not shake too much and prevent continuous shaking. And then by filling it with reinforced concrete, it becomes like a nail in the ground, which can prevent the faults of the ground from breaking, because it is also mentioned in the Holy Quran. that mountains are like nails on the earth because mountains prevent the earth from shaking and we humans can create artificial earthquakes on the earth and prevent the eternal shaking of the earth in the fault zone and it is not only nature that nails like A mountain is like a mountain, humans themselves can create it, i.e. artificially create nails in the earth. These nails tighten the faults and prevent them from constantly vibrating. Of course, this experiment was conducted by geologists in the Texas region of America in 1946, when the oil well was at a shallow depth and they had to drill a well next to the oil well. Injection of water or a solution of water and salt. cause the well oil to rise. After a while they saw; An earthquake occurred in the Texas region of America for a week, and after that, geologists realized that the injection of salt and water solution in the anticline region of this region, where there was also a fault, caused the faults to break and create an artificial one. Earthquake in the region and the release of energy and this earthquake shows that humans can also cause earthquakes. Of course, earthquakes can be caused by other methods, one is like the explosion of a bomb on a fault. Like the bomb explosion in Mallard Karaj region in Alborz province in 1379 at 2:00 p.m. Tahir, 5 provinces that were on the Mesha fault shook and everyone felt it because with the explosion of this bomb that was used for testing in the military area, it suddenly exploded. and took responsibility. They were killed and injured, but because it was on the Masha fault, and this fault starts from about 400 kilometers from Abiq Qazvin and continues to the north of Semnan, it caused the fault to vibrate and release. energy, and perhaps there are other ways to rupture the fault, for example by using many dams in the area of ​​faults and folds of the earth where there are depressions and anticlines. Because the dams intensify the infiltration of water into the ground. Of course, other methods have also been proposed, such as the use of waste and sewage, which causes further destruction of the environment, because burying waste and sewage in fault locations, despite the presence of water, leads to further destruction of the environment on the ground. Therefore, it is possible to break the fault and create and sew strong concrete and cement in it. But all this is a theory, no country has done this yet and it is only a theory. According to geologists, faults are like seams around large blocks and large plates of the earth, and they are the release of the accumulated energy of the earth, and humans cannot prevent its release, and they should only make their houses or structures resistant. For example, by creating wagers, which are in the form of resistant houses, for example, the use of light unilite on the roofs of houses instead of bricks and reinforced concrete buildings, and also like the palm tree, which has deep roots, he made the houses deep and many columns. It made it strong and also by creating spring and rubber under the pillar of the house at the bottom of minus 2 parking lots; Houses are springs like the car you have; He made it so that during an earthquake it only shakes like God Kong, but does not fall, and people are saved, and the construction engineer wants to create springs and pistons in bridges and buildings and prevent the impact of an earthquake like a shock absorber. And these works are useful for saving people.

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Mikayel Grigor Melkumyan added a reply

July 6

Dear Mr. Abbas Kashani,

In the text you provided you are trying to answer to your own question on the possibility to make the earth's faults resistant and prevent them from breaking. I think that everything is possible in this world, but is it necessary to do? Of course not, because you are looking on this problem only from technical point of view but, by all means, you must first of all take into account financial aspect of this problem!!! Even if some methods will be suggested to make the earth's faults resistant and prevent them from breaking the huge funds across the globe and very complex technologies will be needed to do that. So, I consider this as a useless idea and undertaking.

My approach is different. I think that we must concentrate ourselves on the task to make buildings earthquake proof. I devoted myself on solving this important problem, and I created very simple and cost-effective seismic isolation technologies for construction of new and retrofitting of existing buildings. You can read my paper:

Mikayel G. Melkumyan. "Armenia is the World Leader in Development and Extensive Application of Low-Cost Seismic Isolation for Construction of New and Retrofitting of Existing Buildings". - Journal of Architecture and Construction (JAC), Volume 3, Issue 3, 2020, pp.43-60, ISSN: 2637-5796

I am sure that the way to save people from earthquake is to make resilient construction using modern and very efficient technologies!

Best regards,

Mikayel Melkumyan

Doctor of Sciences (Engineering), Professor

Academician of the Saint-Petersburg Arctic Academy of Sciences

Academician of the Athens Institute for Education and Research

President of the Armenian Association for Earthquake Engineering

Vice-President of the International Association of CIS Countries on Base Isolation

Member of the USA Association for Science and Technology

Foreign member of the Research Center of Seismic Resistant Structures of the Institute of Industrial Science, University of Tokyo

Eminent Expert of the Committee of Eminent Experts in International Research Base of Seismic Mitigation and Isolation of Gansu Province in China

Founder of the "Save the Yerevan Schools From Earthquakes" foundation

CEO of the "Melkumyan Seismic Technologies" LLC

+374 (91) 94-54-02

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Christian Ungewitter added a reply

1 day ago

Hello,

I agree in big parts with the opinion of Mikayel Grigor Melkumyan . The much more feasible way to prevent damage of earthquakes is to makes buildings safe.

What I don't see is a technology that can prevent faults from breaking. One problem is the size of a fault. They can be few hundred meters longs up to several hundreds of km. So, in the latter case you would have to provide lot of material to stop the faulting process.

Even if it would be possible the next problem is the very complex stress field and stress distribution in earthquake zones. If you would "fix" one fault the stress would go somewhere else and could trigger an earthquake somewhere else.

At the moment it is even a technically demanding task to stop slow landslides due to e.g. road cuts parallel to slopes. If the rock or soil mass is moving you have to react very quick with the right tools to prevent a failure. It also depends on the force applied by the rock/soil volume that is sliding. When the shear is to high there is is no available technique (special anchors, piles etc.) to prevent such an event. And I'm talking only about local landslides, not about preventing earthquakes.

Best regards

I am working on scale development in behavioral finance by undertaking a mixed-method approach using the exploratory sequential design. The phenomenon has diverse meanings in existing literature (some measuring it in terms of behavior while others use combinations of dimensions such as knowledge and access). I am unclear about its definition, so I want to explore the perspectives about the concept and what components participants feel it includes by taking a phenomenological approach.

My notation for research design is qual→ QUAN→ QUAN. Please guide me as if my approach is right. Do I need to go in so much depth as my main aim is to develop and validate the scale and not undertake a qualitative approach? I just need to take a qualitative viewpoint to support my framework or to guide the initial items bank and dimensions I created using a literature review. Second, if not then is it still remains a mixed-method design? and if yes, then guide me as to how much the sample size should be? I referred to Creswell & Poth's (2018) Qualitative inquiry research design, which says 3-10 (Dukes, 1984) or 5-25 (Polkinghorne, 1989). I am confused, so please if you have any concrete reference, suggest here.

Thanks in advance to the reviewers!

Hi guys, I have developed an online interactive concrete mix design tool for my fellow researchers. It's free to use. Please feel free to suggest modifications or reach out to me if you have any difficulties in understanding how to use it. Please follow the URL https://rajeevroychand.com/concrete-mix-design.html

Scientific discussion

Dear colleagues,

I'm currently modelling a simple 4-point bending test of a concrete beam in Abaqus. However, the load-displacement curve was ascending (without final point), which didn't match the experimental data. I used embedment for reinforcements and tied the supports to the beam. The load is applied to the reference points coupled to the steel blocks tied to the beam. Do you have any suggestions to solve this problem?

I submitted my journal and got some comments, I have answered and corrected all the comments from the reviewer but I don't understand how to answer this question.

any expert researcher help me to explain what I have to do and how?

What can the authors say about the interface problem between the concrete core and the CFRP shells? What is the adhesion type like? How can core-shell bonding affect performance?

What heavy aggregates are available for protective concrete in your country?

What are the benefits and advantages of concrete flooring when used in parking lot floors, and what are the technical requirements and general specifications that should be considered to ensure the quality and durability of these floors?

Hi colleagues,

I am currently working on shear strengthening of reinforced concrete (RC) beams using CFRP wraps and FRCC jackets. As part of my research, I am performing a finite element method (FEM) analysis of a four-point bending test on unstrengthened RC beams using Abaqus to compare with the experimental results. Here is a brief description of the model:

I am using the concrete damage plasticity model to simulate the non-linear behavior and post-cracking responses of concrete. All compressive and tensile properties, as well as damage parameters, have been defined based on recommendations from reference papers and design codes. The model employs roller support boundary conditions to match the experimental setup. For the mesh controls, a C3D8R is used for concrete while a T3D2 is used for rebars.

The force-displacement results from the experiment indicate a mixed failure mode, with initial flexural failure followed by shear failure. The FEM simulation accurately captures the section's capacity and aligns well with the experimental results. However, in the FEM I am unable to replicate the failure/drop observed in the experiment.

Do you have any suggestions on what might be causing this discrepancy?

I have attached some picture of the setup, model parameters and results for reference.

Explain the impact of temperature increase on environment?

What are the realistic applications of self-compacting geopolymer concrete in the world? Are there names of projects implemented with this concrete around the world? Please mention the names and materials that were used for this concrete.

If you can share it with me, please email it to 1939105@brunel.ac.uk.

Many thanks in advance!

Mohammad

I am working with electroluminescence (EL) imaging of photovoltaic panels and need to ensure that the modules are not damaged during testing. I understand that the bias current is usually set based on the short-circuit current (Isc), often as a percentage of it.

However, I have not found concrete information on the safe current range that can be applied without risking damage to the panel. I would like to know if there is a consensus or specific standard regarding the maximum current that can be applied during EL testing. Any normative references, practical experiences, or specific recommendations to ensure the integrity of the modules during these tests would be greatly appreciated.

Dear professors and colleagues，

hello！Recently, while studying the CDP model, I have read the manuscripts of various experts and have gained a lot, but I still have some questions.What I particularly want to know is about the parameters of the simulation:Dilatance angle y, Eccentricity e,Form factor Kc.I sincerely want to inquire about how these values should be taken.

Thank you to all experts for reading the questions！

Modern physics because afterlife prediction is new. More specifically, exact and concrete quantum mechanics.

The afterlife is so unpredictable, empiricism is more accurate than rationalism. https://www.researchgate.net/publication/381108355_Quantum_mechanicsmore_exact_would_predict_the_afterlife_more_accurately_than_relativity_more_theoretical

Violating [(tradition)' = (risk analysis)' = (skin in the game)'] = ethics has many risks.

1)LONG-term higher SELF.

2)Morality is more about concrete empathy than the abstract kind.

3)Criminals risk A LOT.

4)More parsimonous, given the law of identity, and time is an illusion, the individual is more likely eternal than abstract ideas are.

5)We probably realize, upon death, time is an illusion.

6)People evolved to be more easily bored by the abstract than concrete. So, applied mathematics may help teach math.

1)Identify concrete situation.

2)Have empathy.

3)Either already know the language or have an effective enough AI translator.

0)https://www.researchgate.net/publication/380427514_Kalergi_and_Hart-Cellerand_Memetics_White_Antifragility

1)https://www.researchgate.net/publication/380729229_Fractal_Vindication_of_CRT

Kindly greetings,

In a conference I attended before, the peer reviewers believed that the flexural strength, compressive strength, and Young's modulus in the submitted manuscript could not fully represent the mechanical performance of concrete. I would like to ask professors and colleagues, what is the detailed mechanical characteristics of concrete should be included?

Thank you to everyone who saw it!

In the Netherlands, there is much concern about the distance between citizens and government and the lack of mutual trust in each other. Some say this is a result of technology - algorithms and automation of many activities are making the relationship between government and citizen (national but also local) increasingly businesslike and formal. AI could further increase this distance. There are also those who believe that AI can actually help make government more human and improve government-citizen contact. What do you guys think about this and are there people here who know of concrete examples or studies where AI is helping to make government more trusting and human?

Concrete subjects translate easier.

I am trying to simulate a rectangular short column (L/D ratio of 2) for cyclic load under axial compression. I am using the concrete damage plasticity model for concrete. The first problem I am facing is excess lateral stiffness in my ABAQUS model as you can see in the force vs displacement curve. I am trying to match the slope of the red curve generated by the cyclic hysteresis response of the column. The dashed line is the result I got. I have only included the elastic property for concrete for this instance. All the pictures related to the analysis are listed below.

Can anyone tell me what I am doing wrong?

I need to test fire performance of concrete cubes (150 mm * 150 mm * 150 mm). May I know about what kind of arrangement need to conduct this test at home? It shouldn't be a scientific one. But it should have been used to measure fire performance of concrete.

"How do we understand special relativity?"

Discussion

"How do we understand special relativity?"

The Quantum FFF Model differences: What are the main differences of Q-FFFTheory with the standard model? 1, A Fermion repelling- and producing electric dark matter black hole. 2, An electric dark matter black hole splitting Big Bang with a 12x distant symmetric instant entangled raspberry multiverse result, each with copy Lyman Alpha forests. 3, Fermions are real propeller shaped rigid convertible strings with dual spin and also instant multiverse entanglement ( Charge Parity symmetric) . 4, The vacuum is a dense tetrahedral shaped lattice with dual oscillating massless Higgs particles ( dark energy). 5, All particles have consciousness by their instant entanglement relation between 12 copy universes, however, humans have about 500 m.sec retardation to veto an act. ( Benjamin Libet) It was Abdus Salam who proposed that quarks and leptons should have a sub-quantum level structure, and that they are compound hardrock particles with a specific non-zero sized form. Jean Paul Vigier postulated that quarks and leptons are "pushed around" by an energetic sea of vacuum particles. 6 David Bohm suggested in contrast with The "Copenhagen interpretation", that reality is not created by the eye of the human observer, and second: elementary particles should be "guided by a pilot wave". John Bell argued that the motion of mass related to the surrounding vacuum reference frame, should originate real "Lorentz-transformations", and also real relativistic measurable contraction. Richard Feynman postulated the idea of an all pervading energetic quantum vacuum. He rejected it, because it should originate resistance for every mass in motion, relative to the reference frame of the quantum vacuum. However, I postulate the strange and counter intuitive possibility, that this resistance for mass in motion, can be compensated, if we combine the ideas of Vigier, Bell, Bohm and Salam, and a new dual universal Bohmian "pilot wave", which is interpreted as the EPR correlation (or Big Bang entanglement) between individual elementary anti-mirror particles, living in dual universes.

Reply to this discussion

Fred-Rick Schermer added a reply

Abbas Kashani

A lot to work with, Abbas.

However, I am standing in a completely different position, and want to share my work with you. I hope you are interested about this completely distinct perspective.

My claim is that Einstein established a jump that is not allowed, yet everyone followed along.

Einstein and Newton's starting point is the behavior of matter through space. As such, one should find as answer something about the behavior of matter moving through space, and yet Einstein did not do that.

To make the point understandable quickly, Einstein had not yet heard about the Big Bang yet. So, while he devised his special relativity, he actually had not incorporated the most important behavior of matter through space.

Instead, he ended up hanging all behaviors of matter on spacetime. It does not matter that his calculations are correct.

--

Let me find a simple example to show what is going on.

We are doing research on mice in a cage, and after two years we formulated a correct framework that fully captures all possible behaviors of these mice in the cage. That's the setup.

Now comes the mistake:

The conclusion is that the cage controls the mice in their behaviors.

Correctly, we would have said that the mice are in control of themselves, yet the cage restricts them in their behavior. We would not say that the cage controls the mice.

Totally incorrect of course, and yet that is what Einstein did. He established a reality in which matter no longer explains the behavior of matter through space, but made it space (spacetime) that explains the behavior of matter. It is a black&white position that has to be replaced by the correct framework (which is a surprise because it is not based on one aspect, but on both aspects).

--

I know I am writing you from a perspective not often mentioned, and it may not interest you. I'll find out if you are interested in delving deeper into this or not.

Here is an article in which I delve into this matter more deeply:

Article On a Fully Mechanical Explanation of All Behaviors of Matter...

Wolfgang Konle added a reply

"Richard Feynman postulated the idea of an all pervading energetic quantum vacuum. He rejected it, because it should originate resistance for every mass in motion, relative to the reference frame of the quantum vacuum."

Richard Feynman's idea is perfect, and there is no reason to reject it. The existence of vacuum energy, or better dark energy is consistent with Einstein's field equations with a positive cosmological constant.

The energy gain from mass or energy in motion leads to an increasing dark energy density.

The only idea which is missing, is the answer to the question: What happens with the additionally gained energy density?

As an answer to that question I propose the following working hypothese:

This energy is used to recycle star fuel from black holes.

On a first glance, this answer looks as being pure madness, because black holes with their unconvincible gravity seem to be a deposit of matter for eternity.

But in fact there is a plausible possibility. This has to do with the negative energy density of gravitational fields and the non-existence of a negatively definite energy density.

But we need open minded thinking in order to delve deeper into details.

Sergey Shevchenko added a reply

"How do we understand special relativity?"

- the answer to this question, which is really fundamental one, since is about what is some physical theory as a whole; what really means – why and how the postulates of a theory, in this case of the SR, really are formulated, and why and how the postulates

- which in any theory fundamentally – as that happens in mathematics, where axioms fundamentally cannot be proven – aren’t proven; while are formulated only basing on some experimental data, which fundamentally prove nothing, though one experiment that is outside a theory prediction proves that this theory is either wrong, or at least its application is limited.

Returning to the SR, which is based on really first of all four postulates – the SR-1905/1908 versions relativity principle, SR-1905 also on the postulate that light propagates in 3D XYZ space with constant speed of light independently on light source/ an observer’s speeds; and, additionally,

- in both theories it is postulated (i) that fundamentally there exist no absolute Matter’s spacetime, and (ii) - [so] that all/every inertial reference frames are absolutely completely equivalent and legitimate.

In the standard now in mainstream physics SR-1908 additionally to the SR-1905 it is postulated also that observed contraction of moving bodies’ lengths, and slowing down of moving clocks tick rates, comparing with the length and tick rates when bodies and clocks are at rest in “stationary” frames, is caused by the “fundamental relativistic properties and effects”, i.e. “space contraction”, “time dilation”, etc..

Really from yet the (i) and (ii) postulates any number of really senseless consequences completely directly, rigorously, and unambiguously follow, the simplest one is the Dingle objection to the SR;

- from this, by completely rigorous proof by contradiction completely directly, rigorously, and unambiguously it follows , first of all, that

- Matter’s spacetime is absolute, that so some “absolute” frames that are at rest in the absolute 3DXYZ space can exist, while applications, i.e. measurements of distances and time intervals, of moving in the space inertial frames aren’t completely adequate to the objective reality; and

- there exist no the “relativistic properties and effects”.

Etc. However really the SR first of all is based on the indeed extremely mighty Galileo- Poincaré relativity principle.

That is another thing that

- according to SR-1905 relativity principle there is some extremely potent entity “light”, the constancy of which for/by some mystic reasons/ways forces moving bodies to contract and moving clocks to slow down tick rates; and

- the SR 1908 relativity principle is practically omnipotent, so the moving frames, bodies, clocks for/by some mystic reasons/ways really contract/dilate even evidently fundamental space and time.

All that above in the SR really is/are only postulated illusions of the authors, nonetheless, again, the Galileo- Poincaré relativity principle is really . extremely mighty, and the SR indeed in most cases at everyday physical practice is applied in completely accordance with the objective reality. The fundamental flaws of the SR reveal themselves only on fundamental level.

The post is rather long now, so here

Cheers

Sergey Shevchenko added a reply

So let’s continue about what is “special relativity”

In the SS post above it is pointed that Matter’s spacetime is fundamentally absolute, however to say more it is necessary to clarify - what are “space” and “time”, just because of the authors of the SR – and whole mainstream physics till now - fundamentally didn’t/don/t understand what these fundamental phenomena/notions are, the really mystic and simply fundamentally wrong things in the SR were/are introduced in this theory.

What are these phenomena/notions, and what are all other really fundamental phenomena/notions, first of all in this case “Space”, “Time”, “Energy”, “Information”,

- and “Matter”– and so everything in Matter, i.e. “particles”, “fundamental Nature forces” – and so “fields”, etc., which is/are fundamentally completely transcendent/uncertain/irrational in the mainstream philosophy and sciences, including physics,

- can be, and is, clarified only in framework of the Shevchenko-Tokarevsky’s philosophical 2007 “The Information as Absolute” conception, and more concretely in physics in the SS&VT Planck scale informational physical model, in this case it is enough to read

More see the link above, here now only note, that, as that is rigorously scientifically rationally shown in the model, Matter absolutely for sure is some informational system of informational patterns/systems – particles, fields, stars, etc., which, as that is shown in the model, is based on a simple binary reversible logics.

So everything that exists and happens in Matter is/are some disturbances in the Matter’s ultimate base – the (at least) [4+4+1]4D dense lattice of primary elementary logical structures – (at least) [4+4+1]4D binary reversible fundamental logical elements [FLE], which [lattice] is placed in the Matter’s fundamentally absolute, fundamentally flat, fundamentally continuous, and fundamentally “Cartesian”, (at least) [4+4+1]4D spacetime with metrics (at least) (cτ,X,Y,Z, g,w,e,s,ct); FLE “size” and “FLE binary flip time” are Planck length, lP, and Planck time, tP.

The disturbances are created in the lattice after some the lattice FLE is impacted, with transmission to it, by some non-zero at least 4D space, momentum P[boldmeans 4D vector] in utmost universal Matter’s space with metrics (cτ,X,Y,Z). The impact causes in the lattice sequential FLE-by-FLE flipping, which, since the flipping cannot propagate in the lattice with 4D speed more than the flipping speed c=lP/tP [really at particles creation and motion c√2, more see the link, but that isn’t essential here].

Some FLE flipping above along a direct 4D line can be caused by a practically infinitesimal P impact; but if P isn’t infinitesimal, that causes flipping FLE precession and corresponding propagation of the “FLE-flipping point” in the 4D space above along some 4D helix,

- i.e. causes creation of some close-loop algorithm that cyclically runs on FLE “hardware ” with the helix’s frequency ω, having momentum P=mc above, mis inertial mass, the helix radius is λ=λ/P;

- and the helix’s 4D “ axis” is always directed along P – particles are some “4D gyroscopes”.

The post is rather long already, so now

Sergey Shevchenko added a reply

So let’s continue about what is “special relativity”.

In the SS posts above it is pointed that everything that exists and happens in Matter is/are some disturbances in the Matter’s ultimate base – the (at least) [4+4+1]4D dense lattice of FLEs, which [lattice] is placed in the Matter’s fundamentally absolute, fundamentally flat, fundamentally continuous, and fundamentally “Cartesian”, spacetime,

- and that happens always in utmost universal “kinematical” Matter’s space with metrics (cτ,X,Y,Z), and corresponding spacetime with metrics (cτ,X,Y,Z ct), where ct is the real time dimension.

At that particles, most of which compose real bodies, at every time moment exist as “FLE –flipping point” that move along some4D helixes that have frequencies ω, having 4D momentums P=mc, m are inertial masses, a helix radius is λ=λ/P;

- and the helix’s 4D “ axis” is always directed along P – particles are some “4D gyroscopes”.

So in Matter there exist two main types of particles – “T-particles”, which are created by momentums that are directed along the cτ-axis [more generally – by 4D momentums cτ-components, but here that isn’t too essential], and so, if are at rest in the 3DXYZ space, move only along cτ-axis with the speed of light, and at that a T- particle’s algorithm ticks with maximal “own frequency”, the particle’s momentum is P0=m0c, where, correspondingly, m0 is the “rest mass”.

If a such T-particle, after some 3D space impact with a 3D space momentum p, moves also in 3D space with a velocity V, having 4D momentum P=P0+p, its speed along the cτ-axis decreases by the Pythagoras theorem in (1-V2/c2)1/2 , i.e. in reverse Lorentz factor,

- and, at that, despite that the helix’s frequency increases, the algorithm is “diluted by “blank” 3D space FLEs flips. So the “own frequency above” decreases in Lorentz factor, so the algorithm ticks slower; and so, say, moving clocks that are some algorithms as well, tick slower in Lorentz factor as well; if a particle algorithm has some defect, and so at every its tick it can break with some probability, so the particle is unstable and decay, such moving in 3D space particles live longer.

Nothing, of course, happens with time, there is no any the SR’s “time dilation”.

The post is rather long already, so now

Cheers

I am working on designing evolution algorithm based scheduling algorithm using ifogsim. Before that, I want to simulate existing algorithms using ifogsim. Can someone help me on this?

Note: In source code, there is a folder named scheduler.There is a TupleScheduler class in that. I can change this. But at the sametime i may need to change AppModule policy too. Actually I need a concrete suggestion about where to change in ifogsim source code?

Nanomaterials in a powdered form are challenging to use in laboratory concrete specimen casting. This is due to the minute-sized particles and the safety considerations. Therefore, there is a need to use nanomaterials in liquid form without altering their properties when used in the casting of concrete specimens.

After Concrete pouring for beam or other elements, Alkalinity level of concrete increases due to forming of Calcium hydroxide and heat comes out well. My question is, would that alkalinity level persist continuously ?

I want to train neural networks to evaluate the seismic performance of bridges, but the papers online are all based on their own databases and have not been published. Where can I find the relevant dataset? The dataset can include the following content: yield strength of steel bars, compressive strength of concrete, number of spans, span length, seismic intensity, support type, seismic damage level, etc

Actually, I have a CDP model sheet for normal concrete, but I want a sheet for UHPC and Lightweight concrete..!

All the experts kindly guide me ..Thank You so much for your precious time.

1. Fire 2. Earthquake 3. Flood

But the big bill comes from 4. not maintaining them. How can we maintain the structures if we can't?

Because the buildings will start falling down on their own.

Insulation. We cover everything. We cover everything with external insulation and plasterboard. External walls, ceilings, load-bearing structure made of reinforced concrete, all covered with insulation and plasterboard.

From the inside, plasterboard on ceilings and walls

What a nice coolness, but there goes the visual control.

1.And there's an earthquake. How do I see the crack to repair it? In the next earthquake either the crack will get bigger or the ceiling will come down on our heads. In corner columns you can't see any failure from the inside because the inside of the column is covered by the masonry.

2.And rusting an iron breaks the concrete overlay and the concrete and steel cooperation is lost How do I repair something I don't see; neither in the ceiling nor in the column?

3.Catch a fire We will burn like candles. Do you know how nice styrofoam burns?

I am using electrical resistivity tomography (ERT) method to analysis cacks in concrete