Table of Contents
- 1 What is the harmful effect of organic impurities contamination in aggregate?
- 2 Which of the following is are deleterious material in aggregates?
- 3 Is a deleterious material in concrete aggregates?
- 4 What is alkali aggregate reaction in concrete?
- 5 What are deleterious materials?
- 6 Which material is most deleterious?
- 7 How alkali aggregate reaction is harmful?
- 8 What is alkali aggregate reaction how it is harmful and how it can be controlled?
- 9 What are the harmful effects of materials on concrete?
- 10 What are the disadvantages of salts in aggregates?
What is the harmful effect of organic impurities contamination in aggregate?
Besides reactive minerals, aggregates may contain other impurities, such as organic matter, which are harmful to concrete. Organic matter, such as that derived from decaying vegetation, is capable of delaying setting and hardening of concrete.
Which of the following is are deleterious material in aggregates?
Detailed Solution
| Deleterious Substance | Fine Aggregate percentage by weight, max. | Coarse Aggregate percentage by weight, max. |
|---|---|---|
| Uncrushed | Uncrushed | |
| Coal and Lignite | 1.00 | 1.00 |
| Clay lumps | 1.00 | 1.00 |
| Material finer than 75 micron IS sieve | 3.00 | 3.00 |
Is a deleterious material in concrete aggregates?
Deleterious materials are essentially the same as those found in coarse aggregates consisting of clay lumps, shale, soft, friable, or laminated particles, vegetable matter, or other objectionable material.
Which of the following is example of deleterious material?
Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs) and Hydrofluorocarbons (HFCs) are considered to be ‘greenhouse’ gases. Coal tar. Lead and Lead Containing Materials (LCM) are hazardous materials which are neuro-toxic.
What is deleterious material?
Deleterious materials (also known as prohibited materials) are materials that are prohibited for use in a project. structural stability/performance/physical integrity/life-expectancy of a project. non-compliance with regulations. susceptibility to change/deterioration.
What is alkali aggregate reaction in concrete?
Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates.
What are deleterious materials?
Which material is most deleterious?
Asbestos
Asbestos – Asbestos is the most written about deleterious material; Please see our other blogs for information on asbestos hazards and management.
What are the deleterious materials?
Deleterious materials (also known as prohibited materials) are materials that are prohibited for use in a project. This could be for a variety of reasons including: reliability. health and safety.
What is deleterious effect?
Something that has a deleterious effect on something has a harmful effect on it. [formal] Petty crime is having a deleterious effect on community life. Synonyms: harmful, bad, damaging, destructive More Synonyms of deleterious.
How alkali aggregate reaction is harmful?
The effects of alkali–aggregate reaction (AAR) on concrete and structures start at the microstructural level, that is, at molecular and microscopic levels, such as the formation of reaction products in concrete and associated microcracking, which ultimately leads to macro-level effects such as visual cracking.
What is alkali aggregate reaction how it is harmful and how it can be controlled?
It can be controlled using proper portions of supplementary cementitious materials like silica fume, fly ash, and ground granulated blast-furnace slag. Lithium compounds can be used to decrease alkali-silica reactions.
What are the harmful effects of materials on concrete?
Organic impurities, clay, silt and crushed dust, salts, unsound particles, and alkali aggregate reactions. Adverse effects of deleterious materials on concrete includes the increase of water demand in concrete, impair bond strength between cement and aggregate, reduce durability, result in concrete popouts, and impair wear resistance.
What are de-leterious materials in aggregate?
Deleterious materials in aggregate are those substances which detrimentally effect the fresh and hardened properties of concrete for instance strength, workability, and long-term performance of the concrete in which such are used. Deleterious materials and highly undesirable constituents.
What are the disadvantages of using elongated aggregates in concrete?
Concrete produced using flaky and elongated aggregates will be prone to segregation, poor surface finish, high cement and sand demand. Generally rounded, irregular rounded and cubical shapes are preferred in concrete mixes.
What are the disadvantages of salts in aggregates?
Salts coming through aggregates cause reinforcement corrosion and also absorb moisture from the air and cause efflorescence. The BS 882:1992 limits on the chloride ion content of aggregate by mass, expressed as a percentage of the mass of total aggregate. 5. Unsound Particles