1 Dakora

Bre Sulfate Classification Essay

How should I go about choosing my topic?

Begin by reading the explanations below.  Examples of each are provided below!

  • Division Essay: find a topic that people might tend to underestimate or over-simplify.  In other words, choose something that the average person might not know much about, and therefore can't really understand how complex or interesting that topic really is.  Your job in the essay will be to break your topic down into meaningful and important categories.

  • Classification Essay: think about the categories we place things in everyday and the characteristics of those categories.  The topic you choose should allow you to argue that something has been misplaced.

How should I organize this essay?

As you write, keep these guidelines in mind: 

  1. Your thesis statement and introduction will need to explain why these divisions/ classifications should matter to your reader.
  2. Your thesis statement and introduction MUST define or explain the category you plan to discuss (i.e. A sport is a competitive, physical activity therefore cheerleading should be considered a sport.)
  3. You should organize your body paragraphs so that each division or category has it's own paragraph or section. (i.e. cardio exercise is paragraph 1 and weightlifting is paragraph 2, etc.)

Division Essay Examples

If you want to lose weight, simply saying that you're going to "exercise" everyday may not be the most effective way to do so.  Exercising is more complex than many people realize--attaining your goals will involve understanding how different types of exercise can help you achieve your goals.   

Types of Exercise

  • cardio: burns calories and strengthens your heart (running, using an elliptical or stair-stepping machine, etc.)
  • weight lifting: tones muscles, increases physical strength, burns fat (using weights or weighted machines)
  • recreational/sports: depending on the sport, can provide both cardio and toning benefits (cycling, tennis, kayaking)

We could also narrow this topic down a bit further and write about the important differences between different types of cycling.

Types of Cycling:  stationary (exercise) biking, road biking, mountain biking, recreational biking

Classification Essay Examples

To write this type of essay, we'll need to think about things that should or should not be placed in a particular category.

Example: Batman (that's our topic!) is not a superhero (category people place him in), but is simply a local vigilante (category he belongs in).

Ask yourself: Why do I think that...?

  • Does not possess super powers (powers most humans don't possess).  
  • Chooses to be a hero, rather than being "chosen" by others/other forces.

Example: Cheerleading (That's our topic!) should be considered a sport (It belongs in the category, "sports"). 

Ask yourself: Why do I think that...?

  • cheerleaders go to "practice" and must be in good physical shape
  • cheerleaders work together toward a common goal
  • cheerleaders must "try out" for their squad and often compete against other squads

Sample Papers

Changes to sulfate classification

The current and intended new limits for sulfate classes based on 2:1 water/soil extraction test are as follows:

Sulfate class

Current limits

g/l SO4

New limits

mg/l SO4

DS-1

<1.2

<500

DS-2

1.2 – 2.3

500 - 1500

DS-3

2.4 –3.7

1600 - 3000

DS-4

3.8 - 6.7

3100 - 6000

DS-5

>6.7

>6000

The consequence of this adjustment will be to make the ground classification based on soil tests more conservative, eg some soils that were previously classified as DS-2 would now be considered as being DS-3.

The change stems from findings of numerous research ground investigations carried out by BRE and others on BRE concrete trial sites and locations where TSA has occurred. In the majority of cases, the sulfate class limits based on soil extract tests were both lower than sulfate class based on sulfate in groundwater and were also low when compared to the actual occurrence of TSA. The new limits bring sulfate classification based on 2:1 water / soil extract tests into parity with the groundwater based tests.

A review of the historical background to sulfate assessment has thrown light on how the current discrepancy came about. [1]  Guidance for concrete in the ground in terms of sulfate classes based on sulfate in water/soil extracts was introduced by BRS in 1968 in Digest 90. Initially 1:1 water/ soil extract was used and the limits were arbitrarily set at 1.2, 2.5, 5.0 and 10.0 g/l SO3, ie approximately doubling at each step. No field data would appear to have been available for correlation with sulfate classes based on sulfate levels in groundwater. These ball-park limits were converted in 1975 in BRE Digest 174 to 2:1 water / soil extract limits to facilitate easier filtration of the sulfate-containing solution from clays. They were further changed in BRE Digest 363:1991 from SO3 to SO4 units. It is unfortunate that, through these changes, they gained an apparent precision that has imparted greater confidence in the derived classification than is warranted.

 [1] Longworth T I. Development of guidance on classification of sulfate-bearing ground for concrete. Concrete. Vol 38, No 2, February 2004, pp 25 –26.

Leave a Comment

(0 Comments)

Your email address will not be published. Required fields are marked *