Free 20 Questions 20 Marks 20 Mins The blast furnace slag cement has very low permeability and provides good resistance to chloride and sulphate attack which is present in seawater. The blast furnace slag cement is widely used in the marine structure.
Blast furnace slag cement other uses: Used for structures meant for water retaining such as retaining wall, rivers, ports, tunnels for improvement in impermeability. Used in mass concreting works such as dams, foundations which require low heat of hydration. Last updated on Sep 27, 2022 Uttarakhand Power Corporation Limited (UPCL) is soon going to announce the official notification for the UPCL AE 2022.
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What are the best practices to produce marine concrete?
Concrete has had extensive use as construction material for seawalls, jetties, groins, breakwaters, bulkheads, and other structures exposed to sea water. The performance record has generally been good. Cases of comparatively rapid deterioration have usually resulted from failure to consider and compensate of the conditions to which marine concrete is exposed.
The following practices are recommended to produce marine concrete of excellent durability. One, proper mix proportions using the optimum cement content will yield a dense, impervious and relatively unabsorbent concrete. Two, the optimum concrete is 6 and one half to 7 and one half sacks per cubic yard and the water/cement ratio should not exceed 6 gallons per sack of cement to produce a mix that is plastic and workable.
Three, reinforcing steel must have a minimum of 3 inches of concrete cover. Four, type V cement with 5 percent C3A content produces the best results. Five, non-reactive aggregates should be used. Six, an air entraining agent will reduce the danger of deterioration due to freezing and thawing.
What are the dangers of concrete in marine construction?
Concrete that is used in marine settings must withstand very harsh and extreme pressures from the environment. That concrete must withstand agents that may be corrosive. These agents can begin to eat away at steel which will cause the structure to break down and eventually fail.
How much concrete do I need for a marine concrete pier?
Concrete has had extensive use as construction material for seawalls, jetties, groins, breakwaters, bulkheads, and other structures exposed to sea water. The performance record has generally been good. Cases of comparatively rapid deterioration have usually resulted from failure to consider and compensate of the conditions to which marine concrete is exposed.
The following practices are recommended to produce marine concrete of excellent durability. One, proper mix proportions using the optimum cement content will yield a dense, impervious and relatively unabsorbent concrete. Two, the optimum concrete is 6 and one half to 7 and one half sacks per cubic yard and the water/cement ratio should not exceed 6 gallons per sack of cement to produce a mix that is plastic and workable.
Three, reinforcing steel must have a minimum of 3 inches of concrete cover. Four, type V cement with 5 percent C3A content produces the best results. Five, non-reactive aggregates should be used. Six, an air entraining agent will reduce the danger of deterioration due to freezing and thawing.
What are the different types of cement?
Free CT 1: Current Affairs (Government Policies and Schemes) 10 Questions 10 Marks 10 Mins Explanation According to IS 12330 (1988) Use of sulphate-resisting Portland cement is particularly beneficial in such conditions where the concrete is exposed to the risk of deterioration due to sulphate attack, for example, in contact with soils and groundwaters containing excessive amounts of sulphates as well as for concrete in seawater or exposed directly to the sea coast Important Points Portland Pozzolana cement (PPC): It is manufactured by the intergrading of OPC clinker with 10 to 25 percent of pozzolanic material. These rate of development of strength reduces but the ultimate strength remains same. Expansive cement: This cement expands after setting, and hence used for repair work, grouting, etc. Quick Setting Cement:
It is produced by finely grinding the clinkers and increasing the proportion of tricalcium aluminate. C 3 A contributes to high heat of hydration resulting in quick (flash) setting of cement and early strength gain This quick setting property is useful for under water concreting were the ordinary concrete may be flushed off quickly.
The various types of cement and its application are as follows:
| Type of Cement | Where to Use |
| Rapid hardening Cement | Road work where it is must to open the road with minimum delay. |
| Extra Rapid hardening | Concreting in cold weather |
| Low Heat Cement | Mass Constructions like Dams, abutments, etc. |
| Portland Pozzolana Cement | Marine and Hydraulic constructions, Mass concrete structures. |
| Quick Setting Cement | Concrete to be laid under normal water. |
| High Alumina Cement | Where early removal of formwork is required. |
| Hydrophobic Cement | Where long storage or transportation is required. |
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