This website uses cookies to ensure you have the best experience. Learn more

Alkali Reactive Aggregates. What Happens When Alkali Cement Is Low

1076 words - 5 pages

Considerable bad experience has been encountered when alkali reactive aggregates have been used.Low alkali cement is normally required to protect against disruptive
Expansion of concrete which occurs generally due to alkali-aggregate reaction.(a
chemical reaction between alkali’s in the cement and reactive aggregates.Another
means of of controlling alkali-aggregate reactions is by the use of suitable fly ash
or natural pozzolan.If a highly reactive aggregate have to be used then it is necessary
to use a low alkali cement and a pozzolan.

Another design recommendation is the type of the cement to be used.Type-2 cement is
normally used by the Bureau of Reclamation in mass concrete ...view middle of the document...

The amount and type of cement used must be compatible with the strength,durability and temperature requirements of the structure.

Admixtures are incorporated into the mix design as needed to obtain economy,
workability,or certain other desired objectives such as permitting placement over
extended period of time.Admixtures have varying effects on concrete and should be evaluated after thorough study of their effects.Most commonly used admixturees in the design of dam are accelerators,air-entraining agents,water reducing,self controlling admixtures and pozzolans.Calcium chloride which has been used a long time should not be used as an accelerator where aluminium or galvanized metal work is embedded.
When accelerators are used added care will be necessary to prevent cold joints during placing of concrete.Air entraining agents are used to increase the durability of the structure when it is exposed to cycles of freezing and thawing.Good quality pozzolans can be used as replacement for cement without sacrificing later age strength.Pozzolans are less expensive than cement and economically good to use.Since the properties of pozzolans vary widely if it has to be used in the construction of dam it is necessary obtain one that will not introduce adverse qualities into the concrete.Concrete containing pozzolans requires thorough curing to assure good resistance to freezing and thawing

The water used in concrete mix should be free of silt,organic matter,alkali,slats and other impurities.Water containing objectionable amount of chlorides and sulfates is particularly undesirable as they prevent the full development of the desired strength.

Inherently concrete is not a homogeneous material.An approach to homogeneous concrete is made by careful and control of batching and mixing operations which will
result in concrete of uniform quality throughout the structure Because of its on strength
water used in mixing is carefully controlled.This control should start in the stockpiles of
aggregate where an effort must be kept to obtain an uniform and stable moisture content..Water to be added to mix is done by some apparatus which will assure that correct...

Find Another Essay On Alkali Reactive Aggregates. What Happens When Alkali Cement is Low

The Ozone Layer: What Does It Do And What Happens When It's Gone?

1219 words - 5 pages The Ozone Layer: What does it do and what happens when it is depleted?The ozone layer is one of the most debated scientific subjects of the last decade. The growing problem of its depletion is being researched heavily all over the world, and methods are being researched to try and solve the problem. There have also been many debates concerning the relationship between the ozone layer and the onset of global warming. Before solutions can be

A psychological take on what happens when one overdoses on heroin compared with concepts from "Mindfulness."

1101 words - 4 pages June 9, 1999 was the worst night of my life. I overdosed on heroin. I began to make strange gagging noises and was gasping for air. My breathing was ebbed. My lips were blue and my skin had also become a pale bluish color. My friends believed I was going to die.At Burger King, my friends tried to do everything they could with what resources they had. They tried throwing cold water on me, they put ice down my pants, and they slapped me around

We Are All One People. This is an essay about how it doesn't matter who you are or what you think you are, that when tragedy happens we are all the same

601 words - 2 pages hotel. I noticed the long lines of people waiting for a phone.A reporter then said that a plane had gone into the Pentagon and that one was on its way to the White House. This is when I noticed the difference in the room starting to shift. I noticed all these "professionals" that are usually so distant began to change. Oddly enough they began to merge closer and started to put one arm through another and slip arms around the next person to them

What is the role of the inspector and what happens in the rest of the play?

840 words - 3 pages An inspector calls is set in 1912 but was written in 1945. The story is about an inspector interrogating a family about the death of a girl. He speaks to them one at a time and shows them a photograph or Eva. He gets them to confess what they did and he convinces they that they all helped to kill her.Inspector Goole's name is an obvious pun on 'ghoul' a spirit or a ghost. The name makes him sound ghostly and he seems very confident when he

Jewish Festival "Passover" What is it about, why is it important and what happens during the festival

655 words - 3 pages PassoverAO1: Passover or Pesach is very important Jewish festival it celebrates the beginning of the Jewish people. it remembers when the Jews were led out of Egypt by Moses. It is celebrated by Jewish people carrying out rituals and celebrations. The festival itself means a lot to Jews as they celebrate the day that their ancestors gained freedom from being slaves. The story that is told on the day of Passover is that of the Exodus, when the

Macbeth and Jerry(Chocolate War) related to the quote by British author Aldous Huxley "Experience is not what happens to a man. It is what a man does with what happens to him."

580 words - 2 pages NOTE - its pretty decent, but could use more insightBritish author Aldous Huxley said, "Experience is not what happens to a man. It is what a man does with what happens to him." His reactions to these clashes not only shape him, but also give him more knowledge. In books, characters are constantly presented with choices about what to do with conflicts that confront them. A character's choice sets off a catalyst of events that mold him or her

Who is more to Blame for what Happens in the Novel: Frankenstein or the Monster? (Frankenstein by Mary Shelley)

1323 words - 5 pages Who is more to Blame for what Happens in the Novel: Frankenstein or the Monster?In Mary Shelley's novel Frankenstein, the main character Victor Frankenstein, becomes obsessed with the notion of bringing a human being to life. The result is the creation of a monster only known to us as 'the monster'. The monster is hideous, and is therefore rejected by Victor and by society to fend for himself. He soon commits many murders, as a result of his

This essay is a paper that states the "setting" of the story and shows how the setting affected the plot and what happens in the story

897 words - 4 pages narrative with a description of the how bad the weather is on this particular day. He not only describes the sky as "cold and gray" (117), but as "exceedingly cold and gray" (117). There was an "intangible pall over the face of things" (117). The author is expressing that the weather is exceedingly bad, and shows us that the setting is gloomy and dark. He goes on to describe what the area looks like; just how empty the landscape is. "As far as the eye

What do gender theorists mean when they claim that gender is a 'social construct'?

1654 words - 7 pages What do gender theorists mean when they say that gender is socially constructed?To say that, "masculinity and femininity are socially ... constructed dimensions that inform all the forms of our thinking, emotional experience and behaviour", is to say that gender itself is socially constructed, rather than a biological trait, which is similar to the long standing 'nature versus nurture' debate. One's 'sex' is a biological fact; male and female

Who You Know is as Important as What You Know When Starting a New Business

1288 words - 5 pages . Who you know is as important as what you know when starting a new business because network creates opportunities and knowledge gives foundation; together it forms the edge for any prospective businessperson. Who we know creates our network; our network creates our opportunities. Though independence is a quality, one must be able to rely on other’s help and acknowledge that it is a strength. Kay (2004) explains that it is incumbent in the

What Christians Mean when they Say Jesus is the Son of God

773 words - 3 pages What Christians Mean when they Say Jesus is the Son of God Christians believe that the Son of God has God's power and authority, we can see this in many passages about Jesus like in the 'Calming of the storm' (Mark 4:35-41). In this passage Jesus controls the wind and sea, all signs of God's power, Jesus also performed many miracles that show his power and His intentions, to help people get rid of sin and to destroy

Similar Essays

What Happens When We Die Essay

1960 words - 8 pages life can affect the next. Hopefully, God is capable of forgiving ignorance of the truth in those who do not believe and choose to live life their way so that eternal damnation is avoided. One thing is certain, there are truths to be found about our God and what happens to us when we die in the beliefs of others. Ironically and whether one wants to believe it or not, it appears others world views were developed from the heels of Christian

The Big Question: What Happens When We Die?

711 words - 3 pages The big question. No not that, the other one. The "what happens to us after life" question. It is something that has intrigued people everywhere. It has prompted the beliefs and semantics of different cultures all around the world. It started wars, divided people, and now dictates how we are all to act. "We should do this, we should do that. If we don't, we will be punished." I, for one, am tired of it. By all means, think what you will. But

What Happens When Relationship Building Strategies Do Not Work

1099 words - 5 pages within and outside work situations, and what happens when my strategies do not work. Relationship Building Relationship building is something that a political navigator has no trouble doing. They know which people to talk to, which to avoid, and which will do them favors and help them throughout their careers. Gilley (2006) list four strategies to improve relationships and your political savvy. These four strategies are preparation, protection

What Happens When You Do Not Manage Risk

1336 words - 5 pages monitoring and control on a project. (PMBOK, 2008). According to PMBOK (2008) known risks are those that have been identified and analyzed making it possible to plan responses to those risks. Planning responses and knowing what to do if those risks become a reality in the project can be the difference between a successful or unsuccessful process. Kendrick (2009) points out that technical projects often come with a higher risk. This is