Name: concrete damage from low ph water
Uploaded: 2024-11-07T14:48:46.000Z
Duration: 1 min 21 s
Channel: JoVE

K12 Standards

Alabama Course of Study Science

9-12

Earth and Space Science

Earth's Systems

9-12.ESS.2.4.b

Acid Attack on Concrete

تعمل الأحماض التي تتفاعل مع الخرسانة على إذابة عجينة الأسمنت المائي ، مما يؤدي إلى مادة مخففة وضعيفة هيكليا.
تكسر الحموضة الخرسانة عندما ينخفض الرقم الهيدروجيني للماء إلى أقل من 6.5 ، ويتسارع التدهور إذا انخفض مستوى الأس الهيدروجيني إلى أقل من 4.5.
يمكن للمياه التي تحتوي على 15 إلى 60 جزءا في المليون من ثاني أكسيد الكربون ، مثل الماء المثلج الذائب ، أن تتحلل الخرسانة. الماء الخثي الذي يحتوي على أكثر من 60 جزءا في المليون من ثاني أكسيد الكربون شديد التآكل.
مياه الصرف الصحي المنزلية ، على الرغم من كونها قلوية ، تؤدي إلى تآكل المجاري ، خاصة في الحرارة ، عندما تحول البكتيريا اللاهوائية مركبات الكبريت إلى كبريتيد الهيدروجين ، الذي تتأكسد بواسطة البكتيريا اللاهوائية إلى حمض الكبريتيك.
يؤثر معدل انتشار أيونات الهيدروجين من خلال هلام الأسمنت أيضا على معدل الهجوم ، خاصة بعد إذابة هيدروكسيد الكالسيوم وغسله.
يمكن منع هجمات هيدروكسيد الكالسيوم عن طريق تثبيتها باستخدام سيليكات الصوديوم المخففة ، والتي تشكل سيليكات الكالسيوم في المسام الخرسانية.
أثبت تطبيق المعالجات السطحية مثل درجة قطران الفحم ، والدهانات المطاطية أو البيتومينية ، وراتنجات الإيبوكسي فعاليتها في الهجمات الحمضية العامة.

هجوم الحمض على الخرسانة

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عندما تتلامس الأحماض مع الخرسانة، فإنها تبدأ تفاعلًا كيميائيًا يذيب عجينة الأسمنت المائية. تؤدي هذه العملية إلى تليين الخرسانة وإضعافها بنيويا. تُلاحظ هذه المشكلة عادةً في بيئات مثل المداخن ومجاري الصرف الصحي والأماكن الصناعية. تزداد شدة الضرر مع انخفاض درجة حموضة ( الرقم الهيدروجينى) الماء المتفاعل مع الخرسانة إلى أقل من 6.5. على وجه الخصوص، يمكن أن تتسبب درجة الحموضة ( الرقم الهيدروجينى) الأقل من 4.5 في حدوث أضرار جسيمة للخرسانة.

يؤثر معدل انتشار أيونات الهيدروجين عبر هلام الأسمنت أيضًا على معدل هجوم الأحماض، وخاصة بعد إذابة هيدروكسيد الكالسيوم في الخرسانة وغسلها. بالإضافة إلى ذلك، يمكن للمياه التي تحتوي على مستويات من ثاني أكسيد الكربون تتراوح بين 15 إلى 60 جزءًا في المليون، مثل مياه الجليد المذابة، أن تتسبب في تدهور الخرسانة، في حين أن مياه الخث التي تحتوي على أكثر من 60 جزءًا في المليون من ثاني أكسيد الكربون يمكن أن تكون شديدة التآكل، مما قد يؤدي إلى خفض الرقم الهيدروجيني إلى حوالي 4.4.

حتى مياه الصرف الصحي المنزلية يمكن أن تتسبب في تآكل الخرسانة في المجاري، وخاصة في ظل الظروف الدافئة عندما تقوم البكتيريا اللاهوائية بتحويل مركبات الكبريت إلى كبريتيد الهيدروجين. ولمنع هذه الأنواع من الهجمات الحمضية، من المفيد تثبيت هيدروكسيد الكالسيوم باستخدام سيليكات الصوديوم المخففة، والتي تشكل سيليكات الكالسيوم الواقية في مسام الخرسانة. بالإضافة إلى ذلك، أثبتت معالجات السطح مثل قطران الفحم، والمطاط أو الدهانات البيتومينية، والراتنجات الإيبوكسي فعاليتها في مكافحة الهجمات الحمضية العامة.
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تعمل الأحماض التي تتفاعل مع الخرسانة على إذابة عجينة الأسمنت المائي ، مما يؤدي إلى مادة مخففة وضعيفة هيكليا.
الحموضة تكسر ...

Education

JoVE Core

Civil Engineering

الهندسة المدنية

Unit 1

الوحدة الأولى

Permeability of Concrete

نفاذية الخرسانة

KEY TERMS AND CONCEPTS

المصطلحات والمفاهيم الأساسية

concrete damage from low ph water

Concrete damage from low pH water happens when acids react with the hydrated cement paste. This reaction dissolves the paste, so the concrete becomes softer and weaker. The problem is often seen in chimneys, sewers, and industrial settings.

The amount of damage depends on how acidic the water is. When pH falls below 6.5, the attack becomes more severe. A pH below 4.5 can cause major concrete damage. The rate of damage also depends on how fast hydrogen ions move through the cement gel. This effect is especially important after calcium hydroxide has dissolved and been washed away.

Carbon dioxide in water can also harm concrete. Water with 15 to 60 parts per million of carbon dioxide, such as melted ice water, can degrade concrete. Peaty water with more than 60 parts per million can be highly corrosive. It may lower the pH to about 4.4.

Sewage can also corrode concrete in sewers. Warm conditions make this worse. In that setting, anaerobic bacteria convert sulfur compounds into hydrogen sulfide. To limit acid attack, calcium hydroxide can be stabilized with diluted sodium silicate, which forms protective calcium silicates in the concrete pores. Surface coatings such as coal-tar pitch, rubber or bituminous paints, and epoxy resins can also help protect concrete.

Concrete Damage from Low pH Water

permeability of concrete

Concrete Durability and Water Penetration

Concrete durability depends partly on how easily water and gases can move through it. This property, called permeability, is important for judging water-tightness and resistance to chemical attack in concrete structures. Permeability is measured with comparative lab tests. In a typical test, the sides of a concrete specimen are sealed, water pressure is applied to the top surface, and the amount of water that passes through is measured. The test is often run for about ten days until a steady...

sulfate attack on concrete

Concrete Damage from Sulfate Exposure

Concrete damage from sulfate exposure starts with a whitish discoloration, often first seen at the edges and corners. As the attack continues, the concrete can crack and spall. This deterioration happens when sulfates react with hardened concrete and create new compounds that take up more space than the materials they replace. Sulfates may enter concrete from soil, groundwater, or industrial effluents. Inside the concrete, they can form calcium sulfate and calcium sulfoaluminate. The reaction...

effect of sea water on concrete

Seawater Damage and Concrete Durability

Seawater can damage concrete by changing its chemistry, increasing porosity, and lowering strength. In marine settings, concrete is exposed to dissolved salts and repeated wetting, so its durability depends on how much water can enter the material. One major form of damage is the breakdown of ettringite and gypsum, two concrete minerals that can dissolve in seawater. As these materials are lost, the concrete becomes more porous. Salt can also crystallize inside pores, especially above the...

acid attack on concrete

Concrete damage from low pH water happens when acids react with the hydrated cement paste. This reaction dissolves the paste, so the concrete becomes softer and weaker. The problem is often seen in chimneys, sewers, and industrial settings. The amount of damage depends on how acidic the water is. When pH falls below 6.5, the attack becomes more severe. A pH below 4.5 can cause major concrete damage. The rate of damage also depends on how fast hydrogen ions move through the cement gel. This...

alkali aggregate reaction in concrete

How Moisture Cracks Alkali-Reactive Concrete

Alkali-aggregate reaction in concrete can weaken a structure when siliceous minerals in the aggregate react with alkaline hydroxides from cement. The reaction makes an alkali-silica gel, which pulls in water and swells. As the gel expands inside the rigid cement paste, it creates pressure that can crack and disrupt the concrete. The damage comes from both osmotic hydraulic pressure and the swelling of the solid reaction products. Particle size also matters. Fine siliceous particles can cause...

corrosion of reinforcement

Why Concrete Can Fail Around Rebar

Steel reinforcement in concrete can corrode when its protective environment changes. Fresh concrete is highly alkaline because of calcium hydroxide, with a pH of about 13. That high pH helps form a passive iron oxide layer on the steel surface, which slows corrosion. Over time, carbonation, chloride ingress, and cracking can weaken this protection. Concrete contains hydrated cement paste with salts, and it acts as an electrolyte. Different areas of the steel then behave as anodic and cathodic...

key terms and concepts

Learn how acids, carbon dioxide, and sewage can weaken concrete, and how sodium silicate and protective coatings help reduce acid attack.

Concrete Damage from Low pH Water | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

physical-properties-of-minerals-i-crystals-and-cleavage

Physical Properties Of Minerals I: Crystals and Cleavage

Source: Laboratory of Alan Lester - University of Colorado Boulder
The physical properties of minerals comprise various measurable and discernible ...

physical-properties-of-minerals-ii-polymineralic-analysis

Physical Properties Of Minerals II: Polymineralic Analysis

Source: Laboratory of Alan Lester - University of Colorado Boulder
The physical properties of minerals include various measurable and discernible ...

Types of Building Stone

Building stones are sourced by extracting rock from natural rock deposits and shaping it into the specific forms and dimensions needed for building ...

4. Obtain, evaluate, and communicate information about the geologic conditions and processes that form different Earth materials.

9-12.ESS.2.4

Igneous Intrusive Rock

Source: Laboratory of Alan Lester - University of Colorado Boulder
Igneous rocks are products of the cooling and crystallization of high temperature ...

Igneous Volcanic Rock

Source: Laboratory of Alan Lester - University of Colorado Boulder
Igneous rocks are the products of cooling and crystallization of magma. Volcanic rocks ...

Quarrying of Stone

Quarrying involves the meticulous extraction of stone from a quarry by either using controlled explosions or precision cutting techniques to remove the ...

a. Plan and carry out investigations to explore the processes that form plutonic (intrusive) and volcanic (extrusive) igneous rocks of differing compositions and textures. Example: Conduct a crystallization experiment to determine how speed of cooling affects crystal size.

9-12.ESS.2.4.a

Acids interacting with concrete dissolve the hydrated cement paste, leading to a softened and structurally weakened material.
Acidity breaks down the ...

Abrasion Resistance of Concrete

Concrete abrasion can occur from vehicular wear on surfaces or abrasive solids in water, which erodes canal linings.
The shot-blast test evaluates ...

turbidity-and-total-solids-in-surface-water

Turbidity and Total Solids in Surface Water

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Turbidity and total solids are related measurements addressing clarity of ...

b. Analyze and interpret data to explain the effects of mechanical and chemical weathering and erosion on Earth's materials by wind, water, ice, and gravity.

Making a Geologic Cross Section

Source: Laboratory of Alan Lester - University of Colorado Boulder
Geologic maps were first made and utilized in Europe, in the mid-to-late 18th century. ...

c. Construct an explanation using evidence from experiments, models, or data of the processes that create and transform igneous, sedimentary, and metamorphic rocks.

9-12.ESS.2.4.c

Pore Size Distribution

Capillary pores are considerably larger than gel pores, and various pore sizes exist within the hardened cement paste.
In conditions of partial hydration, ...

determination-of-moisture-content-in-soil

Determination of Moisture Content in Soil

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba - The University of Arizona
Demonstrating Author: Bradley Schmitz
Soils normally contain a ...

non-destructive-tests-for-concrete-strength

Non-destructive Tests for Concrete Strength

Non-destructive tests, such as the rebound hammer test and penetration resistance test, can be used to determine the strength of concrete in an existing ...

d. Plan and conduct an investigation on water's effect on surface and subsurface processes. Examples: Use particles of varying sizes to determine how the speed of water impacts particle distribution. Use the porosity and permeability of particles of various sizes to determine how the size and sorting of particles affects water movement.

9-12.ESS.2.4.d

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GIS Software, Hardware, and Sources of GIS Data

A Geographic Information System (GIS) combines specialized software and hardware to effectively manage, analyze, and present spatial and related data. GIS ...

Manipulation and Analysis

GIS manipulation and analysis functions are vital for decision-making and planning. These activities range from data retrieval tasks, such as selecting ...

Using GIS to Investigate Urban Forestry

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Urban forests broadly include urban parks, street trees, landscaped ...

e. Obtain and communicate information about significant geologic characteristics in Alabama and the southeastern United States. Examples: types of rocks, caves, sinkholes, minerals, energy resources

9-12.ESS.2.4.e

The Fossil Record

The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms ...

The Evidence for Evolution

Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of ...

5. Obtain, evaluate, and communicate information about major events in Earth's history.

9-12.ESS.2.5

Radioactive Decay and Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. ...

Isotopes

Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number ...

a. Analyze and interpret data to sequence events in Earth's history, including relative and absolute dating techniques, principles of superposition and crosscutting relationships, igneous intrusions, radiometric dating, and the fossil record.

9-12.ESS.2.5.a

Extinction

The History of Life on Earth
Fossils of organisms that were different from anything alive today had been documented as early as the 17th century, but it ...

b. Construct an explanation based on evidence of how catastrophic and long-term events have impacted life on Earth, including mass extinctions.

9-12.ESS.2.5.b

The Colonization of Land

Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they ...

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among ...

What is Photosynthesis?

Photosynthesis is a multipart, biochemical process that occurs in plants as well as in some bacteria. It captures carbon dioxide and solar energy to ...

c. Construct explanations from evidence of how the flow of energy through Earth's systems has changed over time. Example: Earth's oxygen level was lowest during the Cryptozoic Eon (Precambrian) and highest in the Carboniferous.

9-12.ESS.2.5.c

an-overview-of-bgdgt-biomarker-analysis-for-paleoclimatology

An Overview of bGDGT Biomarker Analysis for Paleoclimatology

Source: Laboratory of Jeff Salacup&#160;- University of Massachusetts Amherst
Throughout this series of videos, natural samples were extracted and ...

an-overview-of-alkenone-biomarker-analysis-for-paleothermometry

An Overview of Alkenone Biomarker Analysis for Paleothermometry

d. Obtain, evaluate, and communicate information about important tectonic and geologic events that have occurred in Alabama over geologic time. Examples: geologic ages and types of rocks, fluctuations in sea levels, temperature changes

9-12.ESS.2.5.d

determining-spatial-orientation-rock-layers-with-brunton

Determining Spatial Orientation of Rock Layers with the Brunton Compass

Source: Laboratory of Alan Lester - University of Colorado Boulder
Most rock units exhibit some form of planar surfaces or linear features. Examples ...

Properties of Transition Metals

Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3&#8211;12 are ...

6. Obtain, evaluate, and communicate information about the theory of plate tectonics.

9-12.ESS.2.6

a. Construct an evidence-based explanation of continental drift, basing conclusions on comparisons of coastlines, fossils, ages of rocks, climate, and magnetic patterns.

9-12.ESS.2.6.a

b. Construct an explanation, based on evidence, of tectonic plate movement, types of plate boundaries, and how boundary type relates to specific tectonic features, including mountain ranges, earthquakes, volcanism, volcanic islands, hotspots, mid-ocean ridges, and faults.

9-12.ESS.2.6.b

c. Develop and interpret a model of Earth's internal structure and composition, including inner core, outer core, asthenosphere, lithosphere, mantle, and crust.

9-12.ESS.2.6.c

d. Analyze data to interpret seismic activity and assess the risk of volcanic eruptions and earthquakes in Alabama and other areas in the United States.

9-12.ESS.2.6.d

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Applications of GIS: Disaster Management and Emergency Response

Geographic Information System (GIS) technology is essential for risk identification, action prioritization, and resource optimization in critical ...

Coordinates and Map Projections

Coordinates and map projections are essential tools in accurately representing the Earth's surface for various applications, ranging from navigation to ...

Mechanisms of Heat Transfer I

Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature ...

Mechanisms of Heat Transfer II

In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the ...

Heat Flow and Specific Heat

Heat is a type of energy transfer that is caused by a temperature difference, and it can change the temperature of an object. Since heat is a form of ...

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Conduction, Convection and Radiation: Problem Solving

There are three methods by which heat transfer can take place: conduction, convection, and radiation. Each method has unique and interesting ...

The Water Cycle

The Earth&rsquo;s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, ...

phase-transitions-vaporization-and-condensation

Phase Transitions: Vaporization and Condensation

The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize ...

Phase Changes

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States of Matter and Phase Changes

The internal energy of a substance&#8212;the total kinetic energy of all its molecules and the potential energy of their associated forces&#8212;depends ...

7. Obtain, evaluate, and communicate information about the role of energy transfer in wind, precipitation, cloud formation, and front formation.

9-12.ESS.2.7

a. Obtain and communicate information to explain how water cycles through the atmosphere, including condensation, evaporation, clouds, types of precipitation, relative humidity, and dew point.

9-12.ESS.2.7.a

Specific Heat

The specific heat capacity of a substance refers to the energy required to increase the temperature of one gram of that substance by one degree Celcius. ...

Temperature and Thermal Equilibrium

Heat and temperature are essential concepts for everyone every day. The study of heat and temperature is part of an area of physics known as ...

Quantifying Heat

Thermal Energy&#160;

Microscopically, thermal energy is the kinetic energy associated with the random motion of atoms and molecules. Temperature is a ...

b. Plan and carry out an investigation to determine the differential heating of land and water and explain how these differences create changes in local and global weather. Example: Heat water and soil under lamps for 10 minutes and allow water and soil to cool for 10 minutes, then apply the results to explain land and sea breezes.

9-12.ESS.2.7.b

definition-measurement-pressure-atmospheric-pressure-barometer

Definition and Measurement of Pressure: Atmospheric Pressure, Barometer, and Manometer

Gas pressure is caused by force exerted by gas molecules colliding with the surfaces of objects. Although the force of each collision is very small, any ...

gas-laws-boyle-s-gay-lussac-charles-avogadro-s-and-ideal-gas-law

Gas Laws: Boyle's, Gay-Lussac, Charles', Avogadro's, and Ideal Gas Law

Through experiments, scientists established the mathematical relationships between pairs of variables, such as pressure and temperature, pressure and ...

Ideal Gas Equation

The ideal gas equation is an equation of state that relates the state variables pressure, volume, temperature, and the number of moles of a hypothetical ...

c. Construct an explanation of how air masses, source regions, fronts, weather changes associated with frontal passage (including cold, warm, occluded, and stationary fronts), air pressure, air density, temperature, cloud types, and precipitation are related to each other.

9-12.ESS.2.7.c

Laminar Flow

Laminar flow refers to the smooth, orderly motion of fluid particles in which each particle follows parallel paths with minimal mixing between layers.
The ...

Bernoulli's Equation

In the middle of the nineteenth century, it was observed that two trains passing each other at a high relative speed get pulled towards each other. The ...

Pressure Gauges

Most pressure gauges, like those on scuba tanks, are calibrated to read zero at atmospheric pressure. Readings from such gauges are called the gauge ...

/files/media/science-education/science-education-thumbs/14712.jpg

d. Use data to construct an explanation of the role of pressure differences in the development of wind systems. Examples: Analyze high and low pressure centers to determine direction of air motion. Calculate pressure gradients to determine the direction of air motion.

9-12.ESS.2.7.d

using-topographic-maps-to-generate-topographic-profiles

Using Topographic Maps to Generate Topographic Profiles

Source: Laboratory of Alan Lester - University of Colorado Boulder
Topographic maps are &#34;plan-view&#34; representations of Earth&#39;s ...

Variation of Atmospheric Pressure

Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the ...

/files/media/science-education/science-education-thumbs/14711.jpg

e. Analyze and interpret data to create a surface map, including high-pressure and low-pressure systems, isobars, wind barbs, cloud types, precipitation, and fronts.

Concrete Damage from Low pH Water

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